Contributions to Zoology, 79 (4) – 2010José L. Carballo; José A. Cruz-Barraza: A revision of the genus Mycale (Poecilosclerida: Mycalidae) from the Mexican Pacific Ocean

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Appendix

Identification key

next section

1. Ectosomal skeleton specialization → 2

- No ectosomal skeleton specialization (Carmia) → 6

2. Isochelae present (Zygomycale) → Mycale (Z.) ramulosa

- Isochelae absent → 3

3. Serrated sigmas (Paresperella) → Mycale (Paresperella) psila

- Not Serrated sigmas (Aegogropila) → 4

4. Sigmas absent → M. (A.) dikinsoni

- Sigmas present → 5

5. Toxas absent → M. (A.) adhaerens

- Toxas present → M. (A.) magnitoxa

6. Raphidotoxas present → M. (C.) aff. magnirhaphidifera

- Raphidotoxas absent → 7

7. Toxas present → M. (C.) contax

- Toxas absent → M. (C.) cecilia

Descriptions of the species

Suborder Mycalina Hajdu, Van Soest and Hooper, 1994

Family Mycalidae Lundbeck, 1905

Genus Mycale Gray, 1867

Subgenus Aegogropila Gray, 1867

Mycale (Aegogropila) magnitoxa sp. nov.

(Figs 3A, 4)

FIG2

Fig. 3. External morphologies. A, Mycale (Aegogropila) magnitoxa sp. nov.; B, Mycale dickinsoni sp. nov.; C, Mycale adhaerens (Lambe, 1894); D, Mycale magnirhaphidifera Van Soest, 1984.

Material examined. Holotype: MNCN 1.01/631, Isla Lobos (Sinaloa), 23º13’27’’N, 106º28’01’’W, 7 m, 3.x.2003. Paratypes: BMNH 2010.11.01.1. LEB-ICML-UNAM-388, Punta Santiago (Colima), 19°05’41’’N, 104°25’22’’W, 2 m, 16.xi.2001. LEB-ICML-UNAM-632, Conchas Chinas (Jalisco), 20º35’16’’N, 105º14’42’’W, 5 m, 8.x.2002. LEB-ICML-UNAM-730, puente Maviri (Sinaloa), 25°34’55’’N, 109°06’52’’W, 2 m, 14.xi.2002. LEB-ICML-UNAM-824, antiguo corral del risco (Nayarit), 20°46’20’’N, 105°32’49’’W, 2 m, 11.vi.2003. LEB-ICML-UNAM-870, Chacala (Nayarit), 21°09’57’’N, 105°13’38’’W, 4 m, 12.vi.2003. LEB-ICML-UNAM-904, Isla Lobos (Sinaloa), 23º13’27’’N, 106º28’01’’W, 7 m, 3.x.2003. LEB-ICML-UNAM-934, Isla Hermano Sur (Sinaloa), 23º11’16’’N, 106º25’11’’W, 6 m, 22.x.2003. LEB-ICML-UNAM-953, Isla Hermano Norte (Sinaloa), 23º10’59’’N, 106º26’24’’W, 8 m, 24.x.2003. LEB-ICML-UNAM-1067, Isla El Crestón (Sinaloa), 23º11’02’’N, 106º25’37’’W, 9 m, 2.ix.2003. LEB-ICML-UNAM-1199, Submarino (Sinaloa), 23º09’59’’N, 106º25’05’’W, 18 m, 5.iii.2005. LEB-ICML-UNAM-1353, faro San Rafael (Baja California Sur), 24º17’53’’N, 110º20’43’’W, 9 m, 26.x.2006. LEB-ICML-UNAM-1494, Isla Venados (Sinaloa), 23º10’15’’N, 106º26’42’’W, 4 m, 26.iii.2007. LEB-ICML-UNAM-1539, Cabo San Lucas (Baja California Sur), 22º52’45’’N, 109º54’15’’W, 1.5 m, 25.x.2007. LEB-ICML-UNAM-1589, Las Monas, Isla Isabel (Nayarit), 21º50’59’’N, 105º52’46’’W, 6 m, 25.ix.2007. LEB-ICML-UNAM-1591, Isla Redonda, Islas Marietas (Nayarit), 20º42’04’’N, 105º34’31’’W, 5 m, 10.iv.2002.

Description. Thin sheet to thick cushion-shaped sponge, 0.4 to 1 cm in thickness, which may extend 12 cm or more on rock surface (Fig. 3A). Alive the sponge is light orange to light red. It is light brown in alcohol. The surface is smooth, and pierced by small pores 200-500 μm in diameter, giving it a punctate appearance clearly visible through the transparent dermal membrane, which is detachable in parts. The pores bear many sieve-like ostia, 80 to 110 μm in diameter. The surface in situ also shows a clear vein pattern of superficial canals, 0.5 to 3 mm in diameter, that lead to slightly elevated small contracted oscules, 2-5 mm in diameter. Consistency is soft, but firm upon preservation in alcohol. Alive the sponge exudes some slime.

Spicules. The species bears mycalostyles as megascleres, and three types of microscleres: anisochelae, sigmas and very long toxas (Table 1). The mycalostyles are straight or slightly curved, sharp and thicker towards the middle of the spicule (Fig. 4A), and with a more or less pronounced head that varies between individuals (Fig. 4B). Measurements: 177-290 × 2-7 μm. Head diameter: from 2.5 to 7 μm.

FIG2

Table 1. Distribution and comparative data for the dimensions of spicules (in μm) of Mycale (Aegogropila) magnitoxa sp. nov. specimens. Values in parentheses are means.

FIG2

Fig. 4. LM and SEM images of spicules of Mycale (Aegogropila) magnitoxa sp. nov. A, Mycalostyles; B, Mycalostyles’ end detail; C, Toxa-I (larger) and Toxa-II (smaller); D, Anisochelae I, side and face views; E, Anisochelae II, side and face views; F, Anisochelae III, side view; G, Sigma; H, Tangential view of ectosomal reticular skeleton; I, Transversal view of choanosomal structure.

Anisochelae of three sizes (Fig. 4D-F). I) 28-42 μm in length, with a palmate head that is ca. 62% of total length of the spicule. This category forms rosettes in the ectosome. II) 18.7-25 μm in length, with palmate head ca. 53% of total length of the spicule. III) 11.5-15 μm, palmate head ca. 56% of total length of the spicule. Sigmas are ‘C’ shaped in two size classes. The larger are numerous, robust, 70-120 × 6-8 μm (Fig. 4G). Smaller and fine sigmas are 25-35 × 1.3 μm, thinly scattered and very slender, and consequently sometimes hard to find. They were not found in some specimens.

Toxas of two types (Fig. 4C): the longest with small central bend, 187-352.5 × 2-5 μm. The shorter is deeply curved 60-157.5 × 1.3 μm.

Skeleton. Plumoreticulate. The ectosomal skeleton is a tangential, triangular or polygonal meshed reticulation (45 a 60 μm wide) of multispicular fibers of mycalostyles (20 to 60 μm in thickness) (Fig. 4H). In some areas it is confused, and with single scattered megascleres. It is easily detachable. Anisochelae I form rosettes in the ectosome. The choanosomal skeleton consists of plumose bundles of megascleres (80-110 μm) ending at the surface (Fig. 4I). Spongin reinforces the skeletal fibres to a varying degree. Microscleres scattered throughout choanosome.

Distribution and habitat. Sea of Cortés (Mexican Pacific Ocean). Baja California Sur, Sinaloa, Nayarit, Jalisco and Colima, on rocks, from the intertidal to 18 m depth (Fig. 1).

Etymology. The proposed name magnitoxa alludes to the large size of their toxas.

Taxonomic remarks. Only two species of Mycale (Aegogropila) are known in the Northeastern Pacific: M. (A.) adhaerens (Lambe, 1893) (see next species) and M. (A.) bamfieldensis Reiswig and Kaiser, 1989. Nevertheless, these two species are clearly different from M. (A.) magnitoxa sp. nov.; the first one has no toxas, and M. (A.) bamfieldense differs from the new species by possessing micracanthoxeas and by having much smaller toxas (19-70 μm).

In the West Atlantic and Caribbean there are three species of the subgenus Aegogropila with long toxas; M. (A.) arndti Van Soest 1984 from the Caribbean, which has sigmas in three categories, and toxas up to 85 μm long (Hajdu and Rützler, 1998), M. (A.) escarlatei Hadju et al., 1995 from the Western Tropical Pacific, with microancanthoxas and toxas in two categories up to 140 μm long (Hadju et al., 1995), and M. (A.) lilianae which posses the longest toxas (300 μm) but clearly differs from M. (A.) magnitoxa sp. nov. by the presence of micracanthoxeas.

The closest NE Atlantic species to M. (A.) magnitoxa is M. (A.) contarenii (Martens, 1824). M. (A.) contarenii is a yellow, yellowish green, ochrous or orange-green massive, semi-encrusting and occasionally lobate sponge, with a surface typically covered by small conules (Van Soest and Hajdu, 2002), while M. (A.) magnitoxa sp. nov., is a red, or light red encrusting sponge with a smooth even surface. This morphological overview distinguishes the two species easily, but these species also differ in their spicules. Toxas are much longer (77 μm to 350 μm) in M. (A.) magnitoxa sp. nov. than in M. (A.) contarenii (70 μm), and the toxas of M. (A.) contarenii have a widely extended central bend. The larger sigmas of M. (A.) contarenii are generally shorter than 70 μm, while M. (A.) magnitoxa sp. nov. presents sigmas usually longer than 100 μm.

Mycale (Aegogropila) dickinsoni sp. nov.

(Figs 3B, 5)

FIG2

Fig. 5. LM and SEM images of spicules of Mycale (Aegogropila) dickinsoni sp. nov. A, Mycalostyles; B, Mycalostyles’ heads detail; C, Typical anisochelae I; D, Anisochelae II; E, Anisochelae III; F, trichodragmata; G, Transversal view of choanosomal structure.

Carmia fascifibula sensu Dickinson, 1945: 25 [not Esperella fascifibula Topsent, 1904]
Material examined. Holotype, here designed, material of Carmia fascifibula Dickinson, 1945 [L35661 D59: NHMLAC] (several fragments), R. V. Velero, Sta. 557-36, Isla Partida, Sea of Cortés, 45 m, 3.viii.1936.

Description. Encrusting to cushion-shaped sponge, up to 1.7 cm in thickness. The largest fragment examined measured 2.9 cm long by 1.2 cm wide. Surface is smooth but uneven, and consistency is soft. Subectosomal canals 0.25 to 0.4 mm in diameter sculpture the surface. Small pores from 33 to 67 μm in diameter are scattered over the surface. Circular or oval shaped oscules, from 0.7 to 1 mm in diameter. Ectosomal membrane is easily detachable (Fig. 3B).

Spicules. The species present mycalostyles, anisochelae in three categories, and rhaphides. Mycalostyles are straight or slightly curved, with a relatively abrupt point (Fig. 5A). Measurements: 370-435 μm × 7-14 μm, with elongate undeveloped tyle, sometimes as true styles (Fig. 5B).

FIG2

Fig. 6. LM and SEM images of spicules of Mycale (Aegogropila) adhaerens (Lambe, 1894). A, Mycalostyles; B, Mycalostyles’ ends detail; C, Anisochelae I; D, Anisochelae II; E, Sigmas; F, Tangential view of ectosomal reticular skeleton.

Anisochelae I) 55-65 μm in length, grouped into rosettes in the surface. They are robust, with the shaft curved in profile view, moderately stout, palmate head ca. 56% of total length, characteristically with the frontal alae of equal length as the lateral ones (Fig. 5C). Anisochelae II) 25 to 30 μm in length, with slender shaft, and with palmate head 65% of total length (Fig. 5D). Anisochelae III) 10-20 long, slender, with a slightly curved shaft, head 40-45% of total length (Fig. 5E). Rhaphides 20-38 μm long by 3.8 to 5 μm thick, mostly grouped into trichodragmata. (Fig. 5F).

Skeleton. The estosomal skeleton consists of a reticulation of tracts of mycalostyles (50 a 90 μm thick) forming triangular meshes (200 to 500 μm) clearly visible to the naked eye (Fig. 3B). Many individual subtylostyles and microscleres are scattered among the tracts and in the organic ectosome. Rosettes of anisochelae I are also present in the ectosome. Choanosomal tracts 100-200 μm in diameter end in brushes carrying the ectosome (Fig. 5G).

Distribution. The species is only known from Isla Partida (Sea of Cortés, Mexican Pacific Ocean) (Fig. 1), at 45 m depth.

Etymology. The species is named after Malcolm Gibson Dickinson, one the first person in studying the sponges from the Sea of Cortés.

Remarks. Dickinson (1945) indentified a specimen collected in Isla Partida (Sea of Cortés) as Carmia fascifibula (Topsent, 1904). However, by having sigmas, M. fascifibula (Topsent, 1924), a valid species from the Azores, is clearly different from Dickinson´s material (Topsent, 1924). Thus, Mycale (Aegogropila) dickinsoni sp. nov. is proposed here as a new species for the material from México.

Although M. fascifibula sensu Dickinson (1945) has the typical tangential reticulum of spicules forming meshes, usual for the subgenus Aegogropila, he assigned his specimens to the genus Carmia because De Laubenfels (1936a) had previously synonymized Aegogropila with Carmia, moving all the Mycale-species with toxas to Carmia. However, M. fascifibula sensu Topsent is well placed in the subgenus Carmia (Topsent, 1904), in view of its lack of a tangential reticulation of spiculo-fibres.

Mycale (A.) dickinsoni sp. nov. is a clearly defined species, and there is no species in the subgenus Aegogropila matching its description (see remarks in the previous species Mycale (A.) magnitoxa sp. nov.). Probably, the only Mycale (Aegogropila) with a similar spicular complement is Mycale (A.) tunicata (Schmidt, 1862) from the Mediterranean Sea. This species also has anisochelae in three categories, and trichodragmas of similar size, but there are some important micromorphological differences among their microscleres. For example, the head of the anisochelae II of M. (A.) dickinsoni sp. nov. presents an extremely long frontal alae almost fusing with the foot, and the lateral alae is characteristically elongated in a profile view (Fig. 5D), which are characteristics not present in M. (A.) tunicata. In addition, the external morphology is also different; M (A.) tunicate consists of a massive base, from which irregular digitate processes arise, and in constrast M. (A.) dickinsoni is an encrusting to cushion-shaped sponge.

Mycale (Aegogropila) adhaerens (Lambe, 1893)

(Figs 3C, 6)

Esperella adhaerens Lambe, 1893: 27; Lambe, 1894: 133
Mycale adhaerens.- Hentschel, 1929: 931; De Laubenfels, 1961: 198; Bakus, 1966: 446
Material examined. LEB-ICML-UNAM-77, Peña de la Virgen (Nayarit), 21º31’05’’N, 105º20’05’’W, 5 m, 22.xi.1999. LEB-ICML-UNAM-221, Isla Tunosa (Sinaloa), 25º34’58’’N, 109º00’51’’W, 2 m, 22.vi. 2000. LEB-ICML-UNAM-242, Isla Tunosa (Sinaloa), 25º34’58’’N, 109º00’51’’W, 2 m, 22.vi.2000. LEB-ICML-UNAM-326, Isla Lobos (Sinaloa), 23º13’49’’N, 106º27’43’’W, 6 m, 26.i.2001. LEB-ICML-UNAM-415, Isla Lobos (Sinaloa), 23º13’49’’N, 106º27’43’’W, 4 m, 17.x.2001. LEB-ICML-UNAM-533, antiguo muelle de atraque (Sinaloa), 23º11’57’’N, 106º25’15’’W, 2 m, 23.iv.2002. LEB-ICML-UNAM-658, Cerro San Carlos (Sinaloa), 25º35’33’’N, 109º02’39’’W, 4 m, 12.xi.2002. LEB-ICML-UNAM-680, Isla Tunosa (Sinaloa), 25º34’58’’N, 109º00’51’’W, 2 m, 12.xi.2002. LEB-ICML-UNAM-796, Mismaloya (Jalisco), 20°31’56.22’’N, 105°17’42’’W, 6 m, 9.vi.2003. LEB-ICML-UNAM-903, Isla Lobos (Sinaloa), 23º13’27’’N, 106º28’01’’W, 7 m, 3.x.2003. LEB-ICML-UNAM-1073 Estero el Bichi (Sinaloa), 25°32’27’’N, 109°05’29’’W, 2 m, 4.iv.2004. LEB-ICML-UNAM-1348 Isla Venados (Sinaloa) 23º10’75’’N, 106º26’42’’W, 4 m, 26.v.2006. LEB-ICML-UNAM-1587, cerro de la Virgen (Sinaloa), 25º36’57”N, 108º58’11’’W 2 m, 12.xi.2002.

Description. Mycale adhaerens is a light orange to yellow-brown encrusting sponge (Fig. 3C), 1.3 to 5 mm thick, spreading across small surfaces (3 cm × 2 cm). In alcohol it is white, almost transparent. Consistency is soft and fragile. The surface is evenly smooth, sculptured by meandering and bifurcating subectosome canals, from 0.2 to 1.5 mm in diameter, radiating from slightly elevated oval-circular oscules, 1.6 to 4 mm in diameter. Surface with abundant, scattered pore areas from 0.25 to 1.5 mm in diameter. The pores bear many ostia, 100 to 300 μm in diameter. Alive the sponge exudes some slime. The ectosomal skeleton is easily detachable in the dry specimens.

Spicules. Megascleres are mycalostyles, and the microscleres are anisochelae in two categories and sigmas (Table 2).

FIG2

Table 2. Distribution and comparative data for the dimensions of spicules (in μm) of Mycale (Aegogropila) adhaerens Lambe, 1894 specimens, with to other Pacific Ocean specimens. Values in parentheses are means.

The mycalostyles are usually straight, occasionally slightly curved, with a short acerate point (Fig. 6A). They measure 180-365 × 2-10 μm. The head may be that of a typical style, or may tend to be that of a subtylostyle (Fig. 6B). The head diameter is from 2.5 to 11.3 μm.

Anisochelae I) 27-48 μm in length, with a palmate head ca. 50% of total length of the spicule (Fig. 6C). Anisochelae II) 8.5 to 27 μm in length, with a palmate head ca.56% of total length of the spicule (Fig. 6D). Sigmas tipically C-shaped and also twisted, from 37.5 to 72.5 μm, in a size class (Figs. 6E, 13A).

Skeleton. The ectosomal skeleton is made of the typical tangential reticulation of tracts of mycalostyles (3-8 mycalostyles per cross section), 50 to 100 μm in diameter, and scattered spicules, forming meshes 150 to 700 μm wide (Fig. 6F). Microscleres and rosettes of anisochelae I scattered in the ectosome. The choanosomal skeleton is made of tracts of mycalostyles that arise from the base of the sponge and end in brushes that carry the ectosome at the sponge surface. Between the tracts the microscleres are strewn at random.

Distribution and habitat. Eastern North Pacific Ocean. From Alaska (Lambe, 1893), and San Juan archipelago, northern USA (Bakus, 1966) to Gulf of California (Mexico, present study). It was found in the states of Sinaloa, Nayarit and Jalisco (Fig. 1). From the intertidal to 60 m depth. Frequently under boulders, between 2-7 depth.

Remarks. This is the first record of M. adhaerens from the Mexican Pacific. Our specimens agree well with the original description of M. adhaerens (Lambe, 1893, as Esperella adhaerens) and with the subsequent records by Bakus (1966) from San Juan (Washington) (see Table 2). M. adhaerens has been also recorded in Japan (Hoshino, 1981), but the spicule types and the micrometries of the Japan specimens are slightly different from the East Pacific records. For example, Hoshino’s specimens have longer mycalostyles (up to 545 μm), and sometimes without the typical anisochelae I in rosettes. Another reason to doubt that they are the same species is the disjunct distribution. Whether or not the present species is the same cited by Hoshino remains a matter of consideration.

Subgenus Carmia Gray, 1867

Mycale (Carmia) aff. magnirhaphidifera Van Soest, 1984

(Figs 3D, 7)

FIG2

Fig. 7. LM and SEM images of spicules of Mycale (Carmia) aff. magnirhaphidifera Van Soest, 1984. A, Mycalostyles; B, Mycalostyles’ ends detail; C, Anisochelae I; D, Anisochelae II; E, Sigmas; F, Rahides; G, Tangential view of ectosomal reticular skeleton, arrow shows a raphidotoxas group; H, Choanosomal structure.

Mycale (Carmia) magnirhaphidifera, Van Soest, 1984
Mycale (Carmia) magnirhaphidifera.- Hajdu and Rützler, 1998: 755; Carballo and Hajdu, 2001: 211; Cruz-Barraza and Carballo, 2008: 754
Mycale cecilia.- Wells and Wells in: Wells et al., 1960: 212. [not M. cecilia De Laubenfels, 1936b, a valid species; see below]
Material examined. LEB-ICML-UNAM-45, cerro el Crestón (Sinaloa), 23º10’46’’N, 106º25’33’’W, intertidal, 26.x.1999. LEB-ICML-UNAM-85, Peña de la Virgen (Nayarit), 21º31’05’’N, 105º20’05’’W, 5 m, 22.xi.1999. LEB-ICML-UNAM-130, Punta Chile (Sinaloa), 23º12’29’’N, 106º25’40’’W, intertidal, 19.ii.1992. LEB-ICML-UNAM-196, Isla Pájaros 1(Sinaloa), 23º15’29’’N, 106º28’25’’W, 8 m, 9.vi.2000. LEB-ICML-UNAM-227, puente Maviri (Sinaloa), 25º34’55’’N, 109º06’52’’W, 2 m, 21.vi.2000. LEB-ICML-UNAM-234, estero el Zacate (Sinaloa), 25º36’25’’N, 109º04’33’’W, 2 m, 21.vi.2000. LEB-ICML-UNAM-259, Paraje Viejo (Sinaloa), 27º55’34’’N, 110º57’12’’W, 8 m, 4.xi.2000. LEB-ICML-UNAM-280, ensenada de Bacochibampo (Sonora), 27º54’37’’N, 110º57’12’’W, 5 m, 6.xi.2000. LEB-ICML-UNAM-404, puente Ventana (Colima), 19º02’08’’N, 104º20’34’’W, 2 m, 15.xi.2001. LEB-ICML-UNAM-407, Cerritos (Sinaloa), 23°18’51”N, 106°29’31”W, 2 m, 30.x.2001. LEB-ICML-UNAM-619, Conchas Chinas (Jalisco), 20º35’16’’N, 105° 14’42’’W, 5 m, 8.x.2002. LEB-ICML-UNAM-687, Islas Verdes (Sinaloa), 25°31’47’’N, 109°05’27’’W, 2 m, 13.xi.2002. LEB-ICML-UNAM-696, estero ‘El Bichi’ (Sinaloa), 25°32’27’’N, 109°05’29’’W, 1 m, 13.xi.2002. LEB-ICML-UNAM-708, cerro Partido (Sinaloa), 25°32’7’’N, 109°05’33’’W, 1 m, 13.xi.2002. LEB-ICML-UNAM-710, estero el Zacate (Sinaloa), 25º36’25’’N, 109º04’33’’W, 2 m, 14.xi.2002. LEB-ICML-UNAM-722, Puente Maviri (Sinaloa), 25º34’55’’N, 109º06’52’’W, 8 m, 14.xi.2002. LEB-ICML-UNAM-776 Conchas Chinas (Jalisco), 20º35’16’’N, 105°14’42’’W, 5 m, 8.x.2002. LEB-ICML-UNAM-820, antiguo Corral del Risco (Nayarit), 20°46’20’’N, 105°32’49’’W, 2 m, 11.vi.2003. LEB-ICML-UNAM-871, Chacala (Nayarit), 21º09’57’’N, 105º13’38’’W, 4 m, 12.vi.2003. LEB-ICML-UNAM-890, Isla el Crestón (Sinaloa), 23º11’02’’N, 106º25’37’’W, 7 m, 10.ix.2003. LEB-ICML-UNAM-917, Isla Lobos (Sinaloa), 23º13’27.7’’N, 106º28’01.6’’W, 7 m, 3.x.2003. LEB-ICML-UNAM-937, Isla Hermano Sur (Sinaloa), 23º11’16.2’’N, 106º25’11.5’’W, 6 m, 22.x.2003. LEB-ICML-UNAM-950, Isla Hermano Norte (Sinaloa), 23º10’59’’N, 106º26’24’’W, 8 m, 24.x.2003. LEB-ICML-UNAM-978, Isla Chivos (Sinaloa), 23º10’40.’’N, 106º24’48.2’’W, 8 m, 26.xi.2003. LEB-ICML-UNAM-981, Isla Cardones (Sinaloa), 23º11’05’’N, 106º24’07’’W, 6 m, 26.xi.2003. LEB-ICML-UNAM-1110, Punta Pinta (Sonora), 31º20’14’’N, 96º05’20’’W, 4 m, 4.iii.2005. LEB-ICML-UNAM-1198, submarino (Sinaloa), 23º09’59’’N, 106º25’05’’W, 18 m, 5.iii.2005. LEB-ICML-UNAM-1217, La Entrega (Oaxaca), 15º42’50’’N, 96º05’20’’W, 4 m, 4.v.2005. LEB-ICML-UNAM-1303, Isla Cacaluta (Oaxaca), 15º38’23’’N, 96º29’01’’W, 4 m, 4.v.2005. LEB-ICML-UNAM-1383, El Requesón, bahía Concepción (Baja California Sur), 26º38’38’’N, 111º49’53’’W, 9 m, 29.x.2006. LEB-ICML-UNAM-1397, El Requesón, bahía Concepción (Baja California Sur), 26º38’38’’N, 111º49’53’’W, 9 m, 29.x.2006. LEB-ICML-UNAM-1438, La Granja, Isla Espíritu Santo (Baja California Sur), 24º25’32’’N, 110º20’55’’W, 0.5 m, 12.iii.2007. LEB-ICML-UNAM-1532, cerro Pelón, Isla Isabel (Nayarit), 21º51’21’’N, 105º53’33’’W, 5 m, 11.ii.2007. LEB-ICML-UNAM-1537, Cabo San Lucas (Baja California Sur), 22º52’45’’N, 109º54’15’’W, 1.5 m, 25.x.2007. LEB-ICML-UNAM-1586, cerro de la Virgen (Sinaloa), 25º36’57’’N, 108º58’11’’W, 2 m, 11.xii.2002.

Description. The species is always thinly encrusting, 0.5-2.5 mm thick, frequently covering several cm2. Color in life most frequently deep-purple to bluish-purple; cream to orange-yellow in shaded zones (Fig. 3D). Preserved specimens are ochre or cream. They are fragile, very soft, and possess a smooth surface. Subectosomal canals are very conspicuous to the naked eye. In live specimens superficial canals (0.6-1.2 mm in diameter) are clearly visible from the surface by a translucent dermal membrane, and lead to slightly elevated oscules (0.3-1.0 μm in diameter). Surface of the sponge is punctuate, with subectosomal spaces 150-500 μm in diameter, abundant and regularly distributed on the surface. Over the spaces are very small ectosomal sieve-like pores 33-70 μm in diameter.

Spicules. Megascleres are mycalostyles, and the microscleres are anisochelae in two categories, sigmas, raphides and raphidotoxas (Table 3).

FIG2

Table 3. Distribution and comparative data for the dimensions of spicules (in μm) of Mycale (Carmia) magnirhaphidifera Van Soest, 1984 specimens. Values in parentheses are means.

Mycalostyles, are slender smooth, mostly straight and with sharp points (Fig. 7A). Measurements: 155-317 × 2.5-5.0 μm; tyle diameter: 2.5-7.5 μm. (Fig. 7B).

Anisochelae I are slender, 20 to 45 μm in length, very slightly curved in profile view, head about ca. 50% of total spicule length (Fig. 7C). Anisochelae II from 10 to 19.5 μm in length, with palmate head ca. 55% of total length of the spicule (Fig. 7D). C-shaped sigmas are not very abundant (Fig. 7E). Measurements: 20-60 μm; raphides, short and fusiform (microxea-like), with a sharp point (Fig. 7F). Measurements: 10-25 μm. Raphidotoxas are very thin, straight, or slightly bent with a sharp point (Fig. 7G), from 230 to 317 μm long.

Skeleton. Ectosomal skeleton consisting mainly of raphidotoxas arranged tangentially without a defined structure (Fig. 7G). Rosettes of anisochelae -I and some other free anisochelae and sigmas are also present. The choanosomal skeleton is made of sinuous ascending tracts of mycalostyles 15-75 μm in diameter, which diverge slightly into brushes when approaching the surface (Fig. 7H).

Distribution. The species is widespread in the Tropical western Atlantic and Pacific Ocean (Carballo and Hajdu, 2001; Cruz-Barraza and Carballo, 2008) (Fig. 1).

Remarks. See in Discussion the paragraph Regarding the presence of the Caribbean M. magnirhaphidifera in the east Pacific Ocean.

Mycale (Carmia) cecilia De Laubenfels, 1936

(Figs 8A-B, 9)

FIG2

Fig. 8. External morphology. A, B, Mycale (Carmia) cecilia de Laubenfels, 1936; C, D, Mycale ramulosa sp. nov.

Mycale cecilia De Laubenfels, 1936b: 447
Mycale microsigmatosa.- Green and Gómez, 1986: 284. [not Mycale microsigmatosa (Arndt, 1927), a valid species from the Western Atlantic]
Mycale angulosa.- Dickinson, 1945: 23. [not Pandaros angulosa (Duchassaing and Michelotti, 1864), a valid species from the Western Atlantic]
Mycale cecilia.- De Laubenfels, 1950: 24; Desqueyroux-Faúndez and Van Soest, 1997: 450; Cruz-Barraza and Carballo, 2008: 751
Mycale maunakea De Laubenfels, 1951
Material examined. [L35519 D46: NHMLAC] Mycale angulosa (Duchassaing and Michelotti, 1964).- Dickinson 1945, Velero Sta. 1039-40 (AHF), Guaymas, Sonora, 10 m, 23.i.1940, LEB-ICML-UNAM-1, Cerritos (Sinaloa), 23º18’27’’N, 106º29’25’’W, 3 m, 31.xi.1997. LEB-ICML-UNAM-20, muelle pesca deportiva (Sinaloa), 23º10’13’’N, 106º25’46’’W, 1 m, 14.x.1999. LEB-ICML-UNAM-23, muelle pesca deportiva (Sinaloa), 23º10’13’’N, 106º25’46’’W, 1 m, 14.x.1999. LEB-ICML-UNAM-40, Isla Lobos (Sinaloa), 23º13’49’’N, 106º27’43’’W, 3 m, 25.x.1999. LEB-ICML-UNAM-43, cerro el Crestón (Sinaloa), 23º10’46’’N, 106º25’33’’W, intertidal, 26.x.1999. LEB-ICML-UNAM-44, cerro el Crestón (Sinaloa), 23º10’46’’N, 106º25’33’’W intertidal, 26.x.1999. LEB-ICML-UNAM-54, estero del pozo (Nayarit), 21º32’48’’N, 105º17’57’’W, 3 m, 19.xi.1999. LEB-ICML-UNAM-73, Peña de la Virgen (Nayarit), 21º31’05’’N, 105º20’05’’W, 5 m, 22.xi.1999. LEB-ICML-UNAM-112, Marina del Cid (Sinaloa), 23º10’89’’N, 106º25’44’’W, 3 m, 27.xi.1999. LEB-ICML-UNAM-127, Punta Chile (Sinaloa), 23º12’29’’N, 106º25’40’’W, intertidal, 19.ii.2000. LEB-ICML-UNAM-140, Chacala (Nayarit), 21º09’57’’N, 105º13’38’’W, 4 m, 20.ii.2000. LEB-ICML-UNAM-148, Chacala (Nayarit), 21º09’57’’N, 105º13’38’’W, 2 m, 20.ii.2000. LEB-ICML-UNAM-164, Isla Cardones (Sinaloa), 23º11’05’’N, 106º24’07’’W, 8 m, 15.iii. 00. LEB-ICML-UNAM- 166, Isla Pájaros (Sinaloa), 23º15’29’’N, 106º28’25’’W, 5 m, 16. iii.2000. LEB-ICML-UNAM- 202, estero el Zacate (Sinaloa), 25º36’25’’N, 109º04’33’’W, 1 m, 21.vi.2000. LEB-ICML-UNAM-223, puente Maviri (Sinaloa), 25º34’55’’N, 109º06’52’’W, 2 m, 21.vi.2000. LEB-ICML-UNAM-229, estero el Zacate (Sinaloa), 25º36’25’’N, 109º04’33’’W, 2 m, 21.vi.2000. LEB-ICML-UNAM-233, estero el Zacate (Sinaloa), 25º36’25’’N, 109º04’33’’W 2 m, 21.vi.2000. LEB-ICML-UNAM-239, Isla Patos (Sinaloa), 25º37’12’’N, 109º00’56’’W, 3 m, 22.vi.2000. LEB-ICML-UNAM-248, Isla Tunosa (Sinaloa), 25º34’58’’N, 109º00’51’’W, 2 m, 22.vi. 2000. LEB-ICML-UNAM- 252, Isla Tunosa (Sinaloa), 25º34’58’’N, 109º00’51’’W, 3 m, 22.vi.2000. LEB-ICML-UNAM-263, Paraje Viejo (Sonora), 27º52’20’’N, 110º52’08’’W, 12 m, 4.xi.2000. LEB-ICML-UNAM-282, Ensenada de Bacochibampo (Sonora) 27º54’37’’N, 110º57’12’’W, 5 m, 6.xi.2000. LEB-ICML-UNAM-350 Isla San José (Baja California Sur) 25°01’41’’N, 110°42’19’’W, 1 m, 29.iii. 2001. LEB-ICML-UNAM-385 punta Santiago (Colima), 19°05’41’’N, 104°25’22’’W 2 m, 16.xi.2001. LEB-ICML-UNAM-401 puente Ventana (Colima), 19º02’08’’N, 104º20’34’’W, 2 m, 15.xi.2001. LEB-ICML-UNAM-468, Isla Redonda (Nayarit), 20°42’04’’N, 105°33’89’’W, 10 m, 5.iv.2002. LEB-ICML-UNAM-479, Careyeros (Nayarit), 20°47’13’’N, 105°71’13’’W, 2 m, 5.iv.2002. LEB-ICML-UNAM-497, Los Arcos (Jalisco), 20°32’73’’N, 105°18’47’W, 4 m, 8.iv.2002. LEB-ICML-UNAM-505, Playa los Muertos (Nayarit), 20°52’29’’N, 105 26’72’’W, 3 m, 9.iv.2002. LEB-ICML-UNAM-552, Ensenada del Pabellón (Culiacán), 22º7’33’’N, 107º18’37’’W, 3 m, 6.vii.2002. LEB-ICML-UNAM-621, Conchas Chinas, (Jalisco), 20º35’16’’N, 105 14’42’’W, 3 m, 8.x.2002. LEB-ICML-UNAM-669, muelle del contenedor (Sinaloa), 25°34’55’’N, 109°03’32’’W, 4 m, 12.xi.2002. LEB-ICML-UNAM-682, Isla Tunosa (Sinaloa), 25º34’58’’N, 109º00’51’’W, 2 m, 12.xi.2002. LEB-ICML-UNAM-684, Islas Verdes (Sinaloa) 25°31’47’’N, 109°05’27’’W, 2 m, 13.xi.2002. LEB-ICML-UNAM-693, estero ‘El Bichi’ (Sinaloa), 25°32’27’’N, 109°05’29’’W, 1 m, 13.xi.2002. LEB-ICML-UNAM-702, Cerro Partido (Sinaloa), 25°32’07’’N, 109°05’33’’W, 1 m, 13.xi.2002. LEB-ICML-UNAM-714, estero el Zacate (Sinaloa), 25º36’25’’N, 109º04’33’’W, 2 m, 14.xi.2002. LEB-ICML-UNAM-724, puente Maviri (Sinaloa), 25º34’55’’N, 109º06’52’’W, 4 m, 14.xi.2002. LEB-ICML-UNAM-747, Paraje Viejo (Sonora), 27º52’20’’N, 110º52’08’’W, 6 m, 26.xi.2002. LEB-ICML-UNAM-792, Mismaloya (Jalisco), 20°31’56.22’’N, 105°17’42’’W, 5 m, 9.vi.2003. LEB-ICML-UNAM-814, Isla Redonda (Nayarit), 20°42’04’’N, 105°33’89’’W, 12 m, 10.vi.2003. LEB-ICML-UNAM-852, Majahuita (Jalisco), 20°29’06’’N, 105°35’03’’W, 7 m, 8.vi.2003. LEB-ICML-UNAM-872, Chacala (Nayarit), 21º09’57’’N, 105º13’38’’W, 4 m, 12.vi.2003. LEB-ICML-UNAM-883, Isla el Crestón (Sinaloa), 23º11’02’’N, 106º25’37’’W, 7 m, 10.ix.2003. LEB-ICML-UNAM-923, Isla Hermano Sur (Sinaloa), 23º11’16’’N, 106º25’11.5’’W, 8 m, 22.x.2003. LEB-ICML-UNAM-954, Isla Hermano Norte (Sinaloa), 23º10’59’’N, 106º26’24’’W, 8 m, 24.x.2003. LEB-ICML-UNAM-975, Isla Chivos (Sinaloa), 23º10’40’’N, 106º24’48’’W, 8 m, 26.xi.2003. LEB-ICML-UNAM-1019, Cerro San Carlos (Sinaloa), 25º35’33’’N, 109º02’39’’W, 2 m, 11.xii. 2002. LEB-ICML-UNAM-1099, La Entrega (Oaxaca), 15º42’50’’N, 96º05’20’’W, 6 m, 14.iv.2004. LEB-ICML-UNAM-1112, punta Pinta (Sonora), 31º20’14’’N, 96º05’20’’W, 4 m, 03.iv.2005. LEB-ICML-UNAM-1124, punta Pinta (Sonora), 31º20’14’’N, 96º05’20’’W, 4 m, 03.iv.2005. LEB-ICML-UNAM-1143, El Muelle (Oaxaca), 15º40’23’’N, 96º31’01’’W, 25 m, 15.iv.2004. LEB-ICML-UNAM-1168, Las Monas, Isla Isabel (Nayarit), 21º50’59’’N, 105º52’46’’W, 6 m, 07.ii.2005. LEB-ICML-UNAM-1200, submarino (Sinaloa), 23º09’59’’N, 106º25’05’’W, 18 m, 03.v.2005. LEB-ICML-UNAM-1216, La Entrega (Oaxaca), 15º42’50’’N, 96º05’20’’W, 4 m, 05.iv.2005. LEB-ICML-UNAM- 1230, Isla Cacaluta (Oaxaca), 15º38’23’’N, 96º29’01’’W, 4 m, 04.viii.2005. LEB-ICML-UNAM- 1287, El Arrocito (Oaxaca), 15º44’25’’N, 96º05’03’’W, 4 m, 11.iv.2005. LEB-ICML-UNAM-1346, Isla Cacaluta (Oaxaca), 15º38’23’’N, 96º29’01’’W, 5 m, 24.vii.2005. LEB-ICML-UNAM-1376, El Requesón (Baja California Sur), 26º38’38’’N, 111º49’53’’W, 9 m, 29.x.2006. LEB-ICML-UNAM-1435, La Granja, Isla Espíritu Santo (Baja California Sur), 24º25’32’’N, 110º20’55’’W, 0.5 m, 12.iii.2007. LEB-ICML-UNAM-1452, muelle petrolero (Baja California Sur), 24º13’23’’N, 110º18’44’’W, 4 m, 12.iii. 2007. LEB-ICML-UNAM-1583, cerro de la Virgen (Sinaloa), 25º36’57’’N, 108º58’11’’W, 2 m, 12.xi. 2002. LEB-ICML-UNAM-1602, piedra del Asadero (Nayarit), 21º34’45’’N, 105º29’45’’W, 2 m, 11.iii. 2007.

Description. Incrusting to cushion-shaped sponge 1-9 mm thick. Specimens commonly red to reddish-orange, or green with yellow, or almost blue, but always with distinctive small orange patches (Fig. 8A, B). Preserved specimens ochre or light brown. Consistency is very soft and fragile after preservation. Surface is smooth. Subectosomal canals, 150-850 μm in diameter, converging to oscula, and subectosomal spaces 20-759 μm, are common. Small ectosomal pores about 33 μm in diameter on sponge surface. Oscules circular to oval, 0.5-4.0 mm in diameter, and commonly elevated from the surface about 3 mm by a translucent dermal membrane.

Spicules. Megascleres are mycalostyles, and the microscleres are anisochelae in one category (Fig. 13B, C) and sigmas (Table 4).

FIG2

Table 4. Distribution and comparative data of external color and the dimensions of spicules (in μm) of Mycale (Carmia) cecilia de Laubenfels, 1936 specimens. Values in parentheses are means.

Mycalostyles are straight, with sharp or blunt points and with a characteristic faintly marked oval head (Fig. 9A, B). Measurements: 130-290 × 2.1-8.8 μm; tyle diameter: 2.5-10.0 μm.

FIG2

Fig. 9. SEM images of spicules of Mycale (Carmia) cecilia de Laubenfels, 1936. A, Mycalostyles; B, Mycalostyles’ ends detail; C, Anisochelae; D, Sigma; E, Tangential view of ectosomal reticular skeleton; F, Transversal view of choanosomal structure.

Anisochelae from 12.5 to 27.5 μm long but in a single category (Figs. 9C, 13B, C) and C-shaped sigmas from 15 to 50 μm (Fig. 9D).

Skeleton. The ectosomal membrane lacks spicules, only free tylostyles are arranged tangentially (Fig. 9E). Sigmas and anisochelae are also distributed throughout the surface. The choanosomal skeleton is plumoreticulate made of ascending multispicular tracts of mycalostyles (30-300 μm in diameter) reinforced with variable amounts of spongin, which slightly diverge into brushes when approaching the surface (Fig. 9F). In some places, a few of these choanosomal tracts 30-150 μm in diameter continue tangentially over the surface. Microscleres, anisochelae, and sigmas common all over the sponge.

Distribution. The species is quite common in the Mexican Pacific (Cruz-Barraza and Carballo, 2008, present study, see Fig. 1). It is common in the east Pacific Ocean from Hawaii (De Laubenfels 1950) to Panama (De Laubenfels 1936b).

Mycale (Carmia) contax (Dickinson, 1945)
Carmia contax Dickinson, 1945: 24
Material examined. The holotype labeled as AHF no. 12; Material- Sta. 751-37 Los Frailes 4-4-37 20 m was not found in the Hallan Hancock collection, currently deposited in the Museum of Natural History Museum of Los Angeles County (NHMLAC) (USA).

Description. No material was studied, so a brief description was adapted from Dickinson, 1945. The sponge is about 2 cm2 by 0.5 cm thick. The surface is irregular. The consistency is softly spongy. Pores and oscules are not evident. Ectosomal membrane very thin and detachable in some places.

Spicules. The megascleres are styles to subtylostyles, and as microscleres present anisochelae in 3 size categories, sigmas, toxas and raphides. Mycalostyles of 300 by 3 μm in average.

Anisochelae I) from 21 to 23 μm, anisochelae II) from 14 to 16 μm and anisochelae III) from 6 to 7 μm in length. Sigmas from 18 to 75 μm. Toxas are long, averaging 55 μm, and raphides are up to 150 μm long.

Skeleton. Ectosomal membrane with some spicules in confusion. The choanosomal skeleton made of ascending multispicular fibres of subtylostyles.

Distribution and habitat. Type locality, Los Frailes (Los Cabos, Lower California); 20 m; sand and algae bottom.

Remarks. The type material of M. contax (Dickinson, 1945) was not found in the Allan Hancock Foundation, where most of the sponges collected by Dickinson were deposited. However, the original description is clear enough to considerer it as a valid species.

The species is distinguished from other species belonging to the subgenus Carmia because of the presence of long toxas (55 μm, in average) and raphides up to 150 μm long. Other two Mycale (Carmia) with long raphides are, M. (C.) magnirhaphidifera Van Soest, 1984, which has longer raphides (from 315 to 367 μm) and shorter sigmas, and does not have toxas, and M. (C.) rhaphidotoxa Hentschel, 1912 from Arafura Sea (Indonesia), which has also larger raphides (200-400 μm), sigmas over 60 μm long, and in addition has not toxas (Carballo and Hajdu, 2001). Other two species with long raphides are M. (Aegogropila) mannarensis Thomas, 1968 from the Gulf of Mannar (India), and Mycale (A.) kolletae Carballo and Hajdu, 2001, from the Atlantic coast of Africa, both clearly different to M. (C.) contax by their typical Aegogropila ectosomal skeleton. M. (Zygomycale) parishi also has long raphides (from 30 to 160 μm), but the spicular complements of this species, and the ectosomal skeleton, are very different to those in M. (C.) contax (see Remarks in M. (Zygomycale) ramulosa).

Subgenus Paresperella Dendy, 1905

Mycale (Paresperella) psila (De Laubenfels, 1930)

(Fig. 10)

FIG2

Fig. 10. Images of spicules and skeletal arrangement of Mycale (Paresperella) psila (de Laubenfels, 1930). A, (LM) Mycalostyles; B, (SEM) Mycalostyles’ ends detail; C, (SEM) Anisochelae I; D, (SEM) Anisochelae II; E, (LM) Toxa; F, (SEM) Sigmas; G, (SEM) Detail of serrated edges. H, Drawing of tangential view of ectosomal structure; I, Drawing of transversal view of choanosomal structure.

Paresperella psila.- De Laubenfels, 1930: 36; De Laubenfels, 1932: 70
Esperella serratohamata.- Lambe, 1895; 130 [not Esperia serratohamata Carter, 1880]
Mycale psila.- Bakus, 1966: 459; Bakus and Green, 1987
Material examined. LEB-ICML-UNAM-329, Isla Lobos (Sinaloa), 23º13’49’’N, 106º27’43’’W, 6 m, 20.iii. 2001. LEB-ICML-UNAM-853, Majahuita (Jalisco), 20°29’06’’N, 105° 35’03’’W, 10 m, 08.vi.2003. LEB-ICML-UNAM-896, Isla el Crestón (Sinaloa), 23º11’02’’N, 106º25’37’’W, 7 m, 12.ix.2003. LEB-ICML-UNAM- 1118, Punta Pinta, Pto. Peñasco (Sonora), 31º20’14’’N, 96º05’20’’W 4 m, 04.iii.2005.

Description. Specimens of this species are thinly to thickly encrusting up to 2.5 mm thick. Live colors range from light yellow to almost white in some specimens, and turn pale brown in alcohol. Maximum substratum coverage of 9 cm long × 5 cm wide. Surface is smooth, but feels slightly hispid. The species presents numerous projections, 2.5 to 5.5 mm high and 1.3 to 1.8 mm thick. The consistency is soft but the projections are firm. Oscules are frequently oval, 0.4 to 1.2 mm in diameter. The body of the sponge and the surface harbor sand, and small fragments of shells.

Spicules. Megascleres are mycalostyles, and microscleres are anisochelae in two categories, toxas, and the typical serrated sigmas of the subgenus in two size classes.

Mycalostyles with shaft that is usually curved, tapering gradually to a sharp point (Fig. 10A, B), 245-325 μm long × 2.5-10 μm wide. With elliptical heads 2.5-7.5 μm in diameter, sometimes weakly mucronate.

Anisochelae I) with head about ca 55% of total spicule length (Fig. 10C). Size: 27-35 μm long.

Anisochelae II) with palmate head ca 56% of total length of the spicule (Fig. 10D). Size: 11-14 μm long.

Toxas are slender, central curve often marked, lateral curves often gentle, gradually tapering to sharp endings (Fig. 10E). Size: 42-63 μm long.

Sigmas with serrated edges (Fig. 10F, G), ‘S-C’ shaped, in two categories. Size category I: 130 to 188 μm long. Size category II: 37 to 60 μm long.

Skeleton.The ectosomal skeleton is made of a tangential reticulation of paucispicular (1-5 spicules), or pluriespicular tracts of mycalostyles (11-18 spicules). Meshes formed by the reticulation are 60 to 200 μm wide. Anisochelae-I are mostly organized in rosettes (Fig. 10H). The choanosomal skeleton is made of ascending tracts of mycalostyles, 150 μm thick (Fig. 10I). Tracts branch towards the ectosome where they diverge in paucispicular tufts 40-100 μm thick that support and slightly pierce the ectosomal reticulum and surface peel.

Distribution and habitat. Northeast Pacific Ocean: Vancouver (Canada) (as Esperella serratohamata Lambe, 1894), San Juan (Washington) (Bakus, 1966), California (De Laubenfels, 1930, 1932; Bakus and Green, 1987), and México (Sonora, Sinaloa, Jalisco and Guerrero) (Fig. 1), on sublittoral rocks.

Remarks. See Bakus (1966).

Subgenus Zygomycale Topsent, 1931

Mycale (Zygomycale) ramulosa sp. nov.

(Figs 8D-E, 11, 12)

Zygomycale parishii.- Green and Gomez, 1986: 288 [not Mycale parishi (Bowerbank, 1875)]
Material examined. Holotype of Raphiodesma parishi Bowerbank, 1875. Dry specimens (BMNH: 1877.5.21.1359) and slides (BK1358-1359). Holotype: MNCN 1.01/632. Isla Lobos (Sinaloa), 23º13’49’’N, 106º27’43’’W, 4 m, 28.xi.1998.Paratypes: BMNH: code 2010.11.01.2. LEB-ICML-UNAM-17, Isla Lobos 1 (Sinaloa), 23º13’49’’N, 106º27’43’’W, 4 m, 28.xi.1998. LEB-ICML-UNAM-22, muelle flota pesca deportiva (Sinaloa), 23º10’93’’N, 106º25’46’’W, 1 m, 14.x.1999. LEB-ICML-UNAM-113, Marina del Cid (Sinaloa), 23º10’89’’N, 106º25’44’’W, 2 m, 27.xi.1999. LEB-ICML-UNAM-157, antiguo muelle de atraque (Sinaloa), 23º11’57’’N, 106º25’15’’W, 4 m, 15.iii.2000. LEB-ICML-UNAM-169, Isla Pájaros (Sinaloa), 23º15’29’’N, 106º28’25’’W, 5 m, 16.iii.2000. LEB-ICML-UNAM- 208, Isla Masocawi (Sinaloa), 25º34’36’’N, 109º00’32’’W, 3 m, 22.vi.2000. LEB-ICML-UNAM-212, cerro San Carlos (Sinaloa), 25º35’33’’N, 109º02’39’’W, 5 m, 22.vi.2000. LEB-ICML-UNAM-216, estero la Chata (Sinaloa), 25º36’22’’N, 109º05’02’’W, 1 m, 21.vi.2000. LEB-ICML-UNAM-237, puente Maviri (Sinaloa), 25º34’55’’N, 109º06’52’’W, 1 m, 21.vi.2000. LEB-ICML-UNAM-545, El Yatch (Sinaloa), 25°36’12’’N, 109°02’16’’W, 3 m, 12.ix.1989. LEB-ICML-UNAM- 547, cerro las Gallinas (Sinaloa), 25°35’11’’N, 109°03’18’’W, 3 m, 22.x.1988. LEB-ICML-UNAM-597, Islas Verdes (Sinaloa), 25°31’47’’N, 109°05’27’’W, 2 m, 13.xi.2002. LEB-ICML-UNAM-659, cerro San Carlos (Sinaloa), 25º35’33’’N, 109º02’39’’W, 6 m, 12.xi.2002. LEB-ICML-UNAM-661, Isla de la Virgen, (Sinaloa), 25°36’58’’N, 108°58’12’’W, 2 m, 12.xi.2002. LEB-ICML-UNAM-671, muelle del contenedor (Sinaloa), 25° 34’55’’N, 109°03’32’’W, 5 m, 12.xi.2002. LEB-ICML-UNAM-884, Isla el Crestón (Sinaloa), 23º11’02’’N, 106º25’37’’W, 7 m, 10.ix.2003. LEB-ICML-UNAM- 922, Isla Hermano Sur (Sinaloa), 23º11’16.2’’N, 106º25’11’’W, 6 m, 22.x.2003. LEB-ICML-UNAM-946, Isla Hermano Norte (Sinaloa), 23º10’59’’N, 106º26’24’’W, profundidad 6 m, 24.x.2003. LEB-ICML-UNAM-1082, La Palma (Sinaloa), 24º37’54’’N, 107º55’50’’W, 6 m, 13.xii.1990. LEB-ICML-UNAM-1089, Estación 7 (Sinaloa), 24º38’40’N, 108º02’51’’W, 3 m, 25.ix.1990. LEB-ICML-UNAM-1437, La Granja, Isla Espíritu Santo (Baja California Sur), 24º25’32’’N, 110º20’55’’W, 0.5 m, 12.iii.2007. LEB-ICML-UNAM-1448, muelle Petrolero (Baja California Sur), 24º13’23’’N, 110º18’44’’W, 4 m, 12.iii.2007. LEB-ICML-UNAM-1550, muelle Petrolero (Baja California Sur), 24º13’23’’N, 110º18’44’’W, 4 m, 12.iii.2007. LEB-ICML-UNAM-1554, Agua de Yépiz (Baja California Sur), 24º35’35’’N, 110º35’53’’W, 1 m, 09.i.2007.

Description. The sponge is very polymorphic. It can grow as thin, flat encrustations 3 mm thick, with oscules which are slightly elevated or flush with the surface, covering areas up to 9 cm long × 7.5 cm wide. It can also be massive with a surface of attachment of 10 × 8 cm, massive-lobose with lobes 0.8 to 2 cm high, and 1.5 to 2.5 cm in diameter, and massive with coalescent branches. It is also frequently found as a large arborescent sponge 45 cm high or more, and up to 30 cm across. This form consists of branches with an irregular outline 3-4 cm across, growing from a short stalk (Fig. 8C-D). The branches may remain isolated along their entire length, or fuse to such a degree that some branches become flabelliform. Commonly the diameter of the branches decreases toward the blind ends, but there is also variation in this feature. The branch form can also have small tubercles 0.1 and 1.5 mm high and 0.75-1.3 mm in diameter. The most common color is red-brown and brownish purple, but dirty yellow specimens are also common. Surface is smooth to uneven but slightly hispid under the binocular microscope. Consistency is soft, spongy, compressible and elastic. In live specimens subectosomal canals are clearly visible leading to slightly elevated, small, contracted, circular or oval shaped oscules, 0.1 to 1.5 cm in diameter (Fig. 8D).

Spicules. The species presents mycalostyles, anisochelae in two categories, palmate isochelae, sigmas also in two size classes, toxas, raphides and micracanthoxeas (Table 5).

FIG2

Table 5. Distribution and comparative data for the dimensions of spicules (in μm) of Mycale (Zygomycale) ramulosa sp. nov. specimens. Values in parentheses are means. *Micracanthoxeas were not measured because these specimens where studied only with an optical microscope.

Mycalostyles are curved and slightly thicker in the middle region (fusiform), with a more or less pronounced head and ending in a sharp point (Fig. 11A-B). Measurements: 157-340 × 2.5-10 μm.

Toxas slender, from 25 to 97 μm in length but in one size, gently curved in the middle and gradually tapering to sharp endings (Figs. 11C, 13D).

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Fig. 11. SEM images of spicules of Mycale (Zygomycale) ramulosa sp. nov. A, Mycalostyles; B, Mycalostyles’ ends detail; C, Toxas; D, Anisochelae I; E, Anisochelae II; F, Isochelae; G, Sigma I; H, Sigma II; I, Raphides; J, Micracanthoxeas.

Anisochelae I) from 38.8 to 51.3 μm, with palmate head ca. 54% of the total length (Fig. 11D), anisochelae II) from 16 to 25 μm, with palmate head ca. 66% of the total length (Fig. 11E), and palmate isochelae from 10 to 15 μm long (Fig. 11F). Sigmas I from 62.5 to 100 μm, stout, C-shaped or contorted as S (Fig. 11G). Sigmas II from 12 to 45 μm, slender, gently curved on most of its extension (Fig. 11H). Raphides 20-46 μm long (Fig. 11I). Micracanthoxeas from 2.5 to 5 μm, straight, sharp pointed and heavily spined, very abundant but difficult to see under optical microscope (Fig. 11J).

Skeleton. Ectosomal skeleton formed by a tangential reticulation of multispicular tracts of mycalostyles (2-18 spicules across) 22 to 60 μm thick, forming meshes 180-450 μm wide (Fig. 12A). The choanosomal skeleton has a plumose architecture; tracts of mycalostyles arise from the base of the sponge and end in brushes that protrude the sponge surface (Fig. 12A-B). Microscleres are strewn at random among tracts. Anisochelae in rosettes are not common but present.

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Fig. 12. Skeletal arrangement of Mycale (Zygomycale) ramulosa sp. nov. A, SEM tangential view of ectosomal structure; B, Scheme of transversal view of choanosomal structure.

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Fig. 13. Spicule dimension-frequency distribution of some Mycale-species: A, M. (Aegogropila) adhaerens sigmas of the specimens LEB-ICML-UNAM-221 (n = 100); B,C, M. (Carmia) cecilia anisochelae of the specimens LEB-ICML-UNAM-1 and LEB-ICML-UNAM-23 (n = 100); D, M. (Zygomycale) ramulosa sp. nov.’ toxas of the specimens LEB-ICML-UNAM-113 (n = 100).

Distribution and habitat. Mexican Pacific Ocean. Sinaloa, Baja California Sur, and Jalisco (Fig. 1). The species has been previously cited as Zygomycale parishii by Green and Gómez (1986). Although the species can be found in open sea environments, it typically lives in lagoons and semi enclosed embayments, between 1 and 6 m depth. On rocks, shells, and attached to small rocks and shells in soft bottoms.

Etymology. The specific name ramulosa comes from the Latin ramulosus, ‘with branches’.

Remarks. The subgenus Zygomycale is clearly characterized by having palmate isochelae (Van Soest and Hajdu, 2002). Only two species from this genus were known thus far; Mycale parishi (Bowerbank, 1875) from the Indo- Pacific Ocean, and M. angulosa (Duchassaing and Michelotti, 1864) from the western Atlantic Ocean. Both species are quite similar in form, color, and skeleton, but spicular differences exist between them (see Burton and Rao, 1932; see Van Soest, 1984 for more detail).

The most important difference between these two species and Mycale ramulosa sp. nov. is the presence of micracanthoxas in the latter. We could think that Bowerbank, and Duchassaing and Michelotti might have overlooked the micracanthoxas due to their minute dimensions. However, this kind of microsclere was not found in the holotype of M. parishi revised by SEM nor in M. angulosa (see Custódio et al., 2002, Lerner et al., 2005). M. parishi also has long raphides (from 30 to 160 μm), which are not present in M. ramulosa sp. nov.

There are five species of Mycale known with micracanthoxeas: M. (Carmia) micracanthoxea (Buizer and Van Soest, 1977) originally reported from the north-eastern Atlantic Ocean, and later from the Strait of Gibraltar (Carballo and García-Gómez, 1994), M. (Aegogropila) bamfieldense from the Pacific Ocean (Reiswig and Kaiser, 1989), M. (A.) escarlatei from the tropical Western Atlantic (Hajdu et al., 1995), Mycale (A.) lilianae also from the tropical Western Atlantic, and Mycale (C.) urizae from the African coast (Carballo and Hajdu, 2001). M. ramulosa sp. nov. is the second Mycale-species bearing micracanthoxea from the Pacific Ocean. Species with a similar ectosomal skeletal arrangement are M. (A.) bamfieldense, M. (A.) escarlatei and M. (A.) lilianae, but these species are predominantly crustose, and don’t posses the typical palmate isochelae of M. (Z.) ramulosa sp. nov.