Aplysina chiriquiensis, Diaz & Soest & Rützler & Guzman, 2005

Diaz, M. C., Soest, Van, Rützler, K. & Guzman, H. M., 2005, Aplysina chiriquiensis, a new pedunculate sponge from the Gulf of Chiriquí, Panamá, Eastern Pacific (Aplysinidae, Verongida), Zootaxa 1012 (1), pp. 1-12 : 3-6

Aplysina chiriquiensis new species

Figures 1–3

Material examined. Holotype ( USNM 1071034 ), paratype A ( USNM 1071035 ), paratype B ( USNM 1071036 ), all from the type locality. Type locality—Bajo Banderas (10–35 m), Gulf of Chriquí , Panamá. Collector: H.M. Guzman, July 3 2003.

Other material. Specimens formerly identified as Aplysina ecuatorensis Desqueyroux­Fandez & van Soest, 1997 (nomen nudum): ZMA Porifera 11262. holotype fragment in alcohol, and ZMA 14900, alcohol specimen. Ecuador, collected by South East Pacific Biological Oceanography program ( SEPBOP) Expedition stat. 18B 773, coordinates 0243' S 08033 'W (­2.7167 ­80.55), depth 20 m, donated by the Smithsonian Oceanographic Sorting Center ( SOSC), date of collection: 1966, Galapagos Islands .

Description. Sponges are ramose, with branches departing from a common stalk (peduncle, 1–2 cm in diameter). Specimens range from 10 to 45 cm in height, with branches 2–40 cm long and 1–4 cm thick. In some specimens, branches are smooth, cylindrical to sub­cylindrical, and with tapering ends ( Figs. 1 , 2a ). Others have stubby or laterally compressed branches, with annular swellings, finger–like or rounded projections, and knobby ends ( Fig. 2b ). External color ranges from pinkish­red or purple to bright yellow, or a combination of these colors. The color of the choanosome is bright yellow. All specimens are aerophobic, changing to dark green when exposed to air and to black after preservation in alcohol. The sponge surface is smooth to the naked eye, but microconulose when viewed by microscope, with regularly distributed conules 100–200 µm in height and 400–600 µm distant from each other. Sponges are compressible and elastic in consistency, almost rubbery. The oscules are circular, 2–4 mm in diameter, with a collar­like membrane, distributed in rows of one or more along the sides of the branches. The specimens with bumpy surfaces have oscules located on top of the round protuberances ( Fig. 2d ).

The skeleton consists of a reticulation made up of concentrically­laminated fibers, 30– 210 µm in diameter, amber in color, but with a predominantly black­appearing (transmit­ ted light), granular pith occupying 15–70 % of the fiber diameter ( Tab. 1). In the ectosome, in particular, fibers have a clear pith rather that a dark, granular one. It was found that the diameter, structure (smooth or granular) and color (clear, black) of the pith can vary greatly within one specimen. In general, fibers are thicker ( Tab. 1) and less regular in diameter at the base or in the stalk than in the mid­section of the sponge body. The reticulum is formed by meshes of varied shapes (polygonal to oval), and mesh diameters range between 200 µm and 1200 µm.

Etymology. named after the Gulf of Chiriqui where the types were collected and the species was found to be very abundant.

Habitat. At the type locality, Aplysina chiriquiensis is very abundant on coral reefs in 15–35 m depth. Its growth form (pedunculate ramose) and rubbery consistency seems well­suited to resisting strong currents.

Distribution. Gulf of Chiriqui ( Panamá) and Galápagos Islands ( Ecuador). Incidental observations have been received from “Archipiélago Las Perlas” in Panamá, and Costa Rica (Guzman, per.comm.), and from the Pacific coast of Colombia (Zea, per.comm.).

Figures

FIGURE 1. Underwater photograph of various specimens of Aplysina chiriquiensis from the Gulf of Chiriquí, Panamá, Eastern Pacific (20 m deep). scale bar = 7 cm.

FIGURE 2. Aplysina chiriquiensis, external morphology. A) The holotype, a typical slender specimen with smooth tapering solid branches, scale bar = 6 cm; B) Paratype A (USNM 1071035), a stubby specimen, scale bar = 2 cm.

FIGURE 3. Skeletal morphology of Aplysina chiriquiensis. A) Cross section of fiber reticulation formed by oval to polygonal meshes. Notice the darker pith. Scale bar = 0.2 mm. B) Cross section of fiber reticulation from the pedunculate base. Notice the thick and deformed fibers. Scale bar = 0.1 mm.