Holothuria (Selenkothuria) carere, Honey-Escandón, Magali, Solís-Marín, Francisco A. & Laguarda-Figueras, Alfredo, 2011

Honey-Escandón, Magali, Solís-Marín, Francisco A. & Laguarda-Figueras, Alfredo, 2011, Holothuria (Selenkothuria) carere, a new species of sea cucumber (Echinodermata: Holothuroidea) from the Mexican Pacific, Zootaxa 2922, pp. 27-33 : 29-32

Holothuria (Selenkothuria) carere n. sp. Honey-Escandón & Solís-Marín

Figs 1–3

Material examined. Holotype UNAM – ICML. 5.179.0. Total length 90 mm (measured along the outside of curved body), January 21, 2010. Collected in Cerritos, Mazatlán, Sinaloa, México (23° 18.524’N, 106° 29.584’W) at 0–1 m depth by F. A. Solís-Marín and Q. Hernández Díaz. Paratypes deposited at UNAM – ICML 5.179.1, two specimens, total length 40 and 78 mm. January 20, 2010. Same locality and collector data as the holotype. UNAM – ICML 5.179.3, one specimen, total length 90 mm. January 21, 2010. Same locality and collector data as the holotype. UNAM-ICML 5.179.3, two specimens, total length 42 and 65 mm. March 3, 2010, collected in El Corralón, Caleta de Campos, Michoacán, México (18º 04.003’N, 102º 43.958’W) at 5–6 m depth by F. A. Solís Marín and J. Arriaga Ochoa. UNAM – ICML 5.179.4, one specimen, total length 60 mm. March 4, 2010, collected in Caletilla, Lázaro Cárdenas, Michoacán, México (18º 03.143’N, 102º 39.034’W) at 3 m depth by F. A. Solís Marín and J. Arriaga Ochoa.

Type locality. Cerritos, Mazatlán, Sinaloa, México (23° 18.524’N, 106° 29.584’W).

Description. Preserved specimens 40 to 90 mm long. Color in alcohol dark brown in the longitudinal mid dorsal area that mixes with lighter brown towards the ventral side in the form of small patches of color, forming a tabby-like pattern. The specimens from Michoacán have, in addition, two rows of visible black spots along the dorsum. Body wall covered by scattered, short, cylindrical tube feet, more numerous on the ventral than on the dorsal surface. On the dorsal body wall also scattered very few tiny papillae that sometimes can be highlighted by lighter or darker patches ( Fig. 1 ). Tube feet of the bivium the same color as lightest parts of the body wall; on the trivium yellowish or light brown.

Mouth terminal, surrounded by 20 dark olive green tentacles (holotype: 0.8 cm length). Base of tentacles surrounded by tiny papillae, more numerous on the radial than the interradial area. Anus terminal, with anal papillae. Body wall up to 2 mm thick.

Ossicles absent from the dorsal and the ventral body wall. Dorsal tube feet with endplates as the only calcareous structure present, up to 300 µm across. Ventral tube feet also without ossicles, only endplates present 460–480 µm across. Ossicles present in the dorsal papillae in the form of tiny rods and pseudo endplates ( Fig. 3 , A). Smooth straight rods of different sizes, 50–130 µm long, with several distal projections, blunted or with double spines. Small rods with one distal perforation, large rods with several. Few with distal bifurcations, with an X-like shape. Pseudo endplates perforated irregularly, 50–60 µm wide and 80–85 long. Tentacles with numerous rods similar to those from the dorsal papillae, of variable sizes, from 45–70 µm up to 140–155 µm long ( Fig. 3 , D). Small rods smooth, few with projections and one distal perforation. Larger rods with distal projections, blunted or with double spines and several distal perforations. Anal papillae with straight smooth rods 30–125 µm long ( Fig. 3 , C). Some with few distal perforations and projections, some with only one distal smooth perforation. Very few X-like shaped rods and the presence of pseudo endplates (25 µm wide x 60 µm long) is rare. Papillae at the base of the tentacles also with two kinds of rods ( Fig. 3 , B). First type, smooth straight rods, some slightly curved, with distal projections (generally two) that bifurcate and join together forming one or more perforations with dentate or smooth rim; generally big in size, from 80 to 130 µm long. Second type, smooth slightly curved thin rods without distal projections or perforations; smaller in size, from 15 to 80 µm long.

Longitudinal muscles divided, completely attached. Calcareous ring ( Fig. 2 , B) with radial plates as wide as two times the length of the interradial plate. Single, well developed Polian vesicle, 1/8 to 1/4 of body length. In one specimen, additionally two Polian vesicles 3 mm long. Cuvierian tubules present. Stone canal long (1/7 to 1/8 of body length) ending in a long, flat madreporite with a tapering end ( Fig. 2 , A). Gonads present, fully grown in three specimens. Right respiratory tree extending forward to the total length of the body.

Etymology. The specific epithet carere in Latin means “to be without”. It is here used as a noun in apposition and refers to a unique characteristic of this sea cucumber, which is the absence of ossicles in the body wall and dorsal and ventral tube feet.

Ecology. This species is found in shallow waters, from intertidal to 6 m depth. Specimens from Mazatlán were found completely hidden inside holes within a big rock, with only the tentacles outside for feeding, in a dendrochirote-like way of living. The specimens from Michoacán were found completely concealed under rocks. Apparently the species is highly plastic in using different feeding strategies, not specialized in a specific habitat.

Geographic distribution. Holothuria (Selenkothuria) carere n. sp. is known only from two localities: Mazatlán, Sinaloa, México (type locality) in the lower limit of the Gulf of California and Caleta de Campos, Michoacán, México, in the Mexican Pacific Ocean.

Figures

FIGURE 1. Holothuria (Selenkothuria) carere n. sp. Holotype, UNAM-ICML 5.179. 0. Lateral view, dorsal papillae are evident. Total length 90 mm.

FIGURE 2. A. Madreporite and C. Calcareous ring from the holotype UNAM-ICML 5.179. 0. Scale in A and B = 1 mm.

FIGURE 3. Holothuria (Selenkothuria) carere n. sp. A. Rods from dorsal papillae; B. Rods from papillae at the base of the tentacles; C. Rods from anal papillae; D. Rods from tentacles.