The littoral sea cucumbers (Echinodermata: Holothuroidea) of Guam re-assessed – a diversity curve that still does not asymptote

The Micronesian island of Guam has been an important site for the study of littoral tropical holothurian taxonomy for almost 200 years. Despite substantial attention by both expeditions and resident taxonomists, new records are still regularly added to the fauna, demonstrating the challenge of documenting even such large and well-known animals in a small hyper-diverse area. Guam is the type locality of species described by Quoy & Gaimard (1833) and Brandt (1835). A survey of the sea cucumber fauna by Rowe & Doty (1977) led to one of the most used guides for the identification of tropical Pacific sea cucumbers because of the color illustrations of living animals it presented. Focus on echinoderms including holothurians continued with numerous new records added in the following decades. Paulay (2003a) summarized the fauna last, recording 46-47 species. At this stage the fauna was thought to be well documented. A week-long workshop on holothurian systematics sponsored by the National Science Foundation PEET (Partnerships for Enhancing Expertise in Taxonomy) project in 2010 included a substantial field work component, sampling both during the day and night, with snorkeling and SCUBA, across a variety of habitats. This survey yielded 40 species, including numerous new records and even species. Further sampling by Kerr’s lab since the workshop has added additional records. The littoral holothuroid fauna of Guam now comprises 65 species in 17 genera and 7 families. Half of the 19 newly recorded species are the result of unravelling cryptic species in complexes, the other half are based on new collections. Eleven species are known from single specimens, suggesting that much still remains to be learned about the fauna

A revision of Holothuria (Halodeima) kefersteinii (Selenka, 1867) and the revival of Holothuria inornata Semper, 1868 from sea cucumbers collected in Mexico and Central America

Honey-Escandón, Magali, Solís-Marín, Francisco A. (2018): A revision of Holothuria (Halodeima) kefersteinii (Selenka, 1867) and the revival of Holothuria inornata Semper, 1868 from sea cucumbers collected in Mexico and Central America. Zootaxa 4377 (2): 151-177, DOI: https://doi.org/10.11646/zootaxa.4377.2.

Selenkothuria Deichmann 1958

Subgenus Selenkothuria Deichmann, 1958 Diagnosis (after Deichmann, 1958): Soft-skinned forms with numerous cylindrical feet, forming a distinct ventral sole, sometimes arranged in three broad bands; dorsally numerous minute papillae, not conspicuous, rarely forming low warts. Tentacles more or less terminal in position, often bushy, adapted for plankton catching. Inner anatomy not remarkable; certain species with numerous stone canals in one or two tufts on both sides of the dorsal mesenterium, others with a single large one attached to the right side; usually one Polian vesicle; gonads as divided threads in a tuft behind the low calcareous ring; Cuverian organs present in some forms. An external layer of tables usually completely lacking, though vestiges of tables sometimes found in young individuals of certain species. The inner layer consisting of small rods or plates, smooth or spinous. Ventral feet with large end plate and walls supported by rods or plates of same size as those in the skin, rarely special supporting rods or perforated plates present. Dorsal appendages with reduced end plate or none, and often more curved, shorter rods. In some species, rods present in the cloacal retractor muscles and in the respiratory trees. Color dull gray, dark brown, olive green or black with or without two rows of dark spots and darker anterior and posterior end. Type species: Holothuria lubrica Selenka, 1867.Published as part of 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, pp. 27-33 in Zootaxa 2922 on pages 28-29, DOI: 10.5281/zenodo.20242

Holothuria (Selenkothuria) carere Honey-Escandón, Solís-Marín & Laguarda-Figueras, 2011, n. sp.

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 (18 º 04.003’N, 102 º 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 (18 º 03.143’N, 102 º 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.Published as part of 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, pp. 27-33 in Zootaxa 2922 on pages 29-32, DOI: 10.5281/zenodo.20242

PROPUESTA METODOLÓGICA PARA EL MAPEO DE COMUNIDADES ARRECIFALES

La cartografía de arrecifes coralinos se ha constituido en una valiosa herramienta para conocer diversos fenómenos y procesos biológicos que ocurren en estas comunidades, relacionados con su dimensión espacial. Los mapas se han empleado para representar la conformación topográfica de la formación arrecifal, los patrones de distribución de los corales y otras especies, como referentes para estudios de sucesión y para propósitos aplicados relacionados con programas de conservación y desarrollo sustentable. En este trabajo se presenta una propuesta metodológica de mapeo subacuático, aplicada a la comunidad arrecifal de Bahía San Agustín, Huatulco, Oaxaca, que puede ser utilizada en otros sitios del Pacífico Tropical Mexicano. El protocolo de mapeo consiste en cuatro fases generales: 1) planeación y organización; 2) levantamiento topográfico; 3) procesamiento de la información; y, 4) cartografía. Se obtuvieron dos mapas batimétricos, uno de representación bidimensional (2D) y otro tridimensional (3D), que muestran características del relieve complementarias