Callyspongia (Callyspongia) pedroi, Busutil & García-Hernández & Díaz & Pomponi, 2018

Busutil, Linnet, García-Hernández, María R., Díaz, M. Cristina & Pomponi, Shirley A., 2018, Mesophotic sponges of the genus Callyspongia (Demospongiae, Haplosclerida) from Cuba, with the description of two new species, Zootaxa 4466 (1) : -

Callyspongia (Callyspongia) pedroi sp. nov.

( Figs. 1a–e , 2a–d )

Material examined. Holotype: ANC 0 2.034, Cuba, Joint Cuba – U.S. Expedition R/ V F.G. Walton Smith, site C– 12A, Faro Roncali (W coast, Cuba), 21.868604° N 84.962657° W, depth 62.5 m, mesophotic coral reef, 22 May 2017, Collectors: M. C. Díaz & L. Busutil.

Description. External morphology: Delicate cylindrical branches (3–6 mm in diameter, 10–14 cm long) that rarely anastomose, smooth surface to the naked eye, microconulose when observed microscopically ( Fig. 1a–e ). No distinct base, but specimens attach to the substrate at a few points. Oscules 1–3 mm in diameter ( Fig. 1d–e ), oval and flush with the surface, separated by 3–4 mm, arranged in rows on one side of the branch. The diameter at the tips sharply decreases, ending always in a pointed, bent end. Color light reddish to pink externally, tan internally. Tan in alcohol. Smooth surface, but rough to the touch. Soft, flimsy in consistency. No sand or foreign material on the surface. Subdermal round cavities (0.5–1 mm), abundant throughout the body, are evident to the naked eye ( Fig. 1d ).

Spicules: Fusiform oxeas ( Fig. 2d ), 60– 82.4 –100 x 1.25– 2.5 –5 µm.

Skeleton: Ectosome and choanosome have well–developed primary and secondary tangential fibers ( Fig. 2a– c ); no tertiaries can be distinguished. Primary fibers (20–40 µm in diameter); secondary fibers (10–15 µm in diameter). In the ectosome, large meshes (120–425 µm in diameter) and smaller meshes (50–350 µm). In the choanosome, a longitudinal section of the branch shows a peripheral condensation of the skeleton, with regular and condensed meshes at the surface that become more variable towards the interior of the branch. Meshes are angular, with various shapes ranging from triangular, to square or polygonal. Large primary meshes range from 200–500 µm diameter, while smaller secondary meshes are 40–330 µm. All fibers are cored, primaries with 1–6 spicules, and secondaries with 1–3 spicules ( Fig. 2c ). The presence of a peripheral condensation of the reticulation, and overall skeletal morphology indicates the closeness of this species with the subgenus Callyspongia Duchassaing & Michelotti, 1864 .

Distribution and ecology. Northwest, west, southwest, southeast and northeast coasts of Cuba ( Table 2), mesophotic coral reef, depth range 44.4–102.4 m. At site C–50 ( Table 1, depth 91.1 m) another specimen of similar size (12 cm long) and pink in color, similar to the holotype ( Fig. 1b ), was observed but not collected.

Remarks. Based on external morphology, primarily the delicate nature of the branches, Callyspongia (C.) pedroi sp. nov. is similar to Callyspongia arcesiosa De Laubenfels, 1936 and Callyspongia (C.) densasclera Lehnert & Van Soest, 1999 . However, Callyspongia (C.) pedroi sp. nov. differs from Callyspongia arcesiosa by the larger size of its fibers, and the diameter of the meshes that are at least double in size. The spicules of Callyspongia (C.) pedroi sp. nov. are 30% of the size of the spicules of Callyspongia (C.) densasclera , which is also described as having an abnormally dense conglomeration of spicules (measuring 184–232 x 6.5–8 µm) in the fibers, a fact not observed for Callyspongia (C.) pedroi sp. nov. Callyspongia (C.) densasclera has hastate oxeas, occasionally styles, while in Callyspongia (C.) pedroi sp. nov., oxeas are always fusiform ( Tables 3, 4).

Figures

FIGURE 1. Callyspongia (C.) pedroi sp. nov. a) Holotype in live habit b) Other specimen in live habit, but not collected c-d) Holotype on deck e) Microconulose surface, and oval flushed osculum.

FIGURE 2. Callyspongia (C.) pedroi sp. nov. a) Perpendicular section of skeleton showing peripheral condensation of reticle (4X) b) Ectosome showing large meshes and spiny termination of the skeleton on the surface (20X) c) Fibers discretely cored (20X) d) Fusiform oxeas (400X).