Agelas cervicornis ( Schmidt, 1870 )

Parra-Velandia, Fernando J., Zea, Sven & Van Soest, Rob W. M., 2014, Reef sponges of the genus Agelas (Porifera: Demospongiae) from the Greater Caribbean, Zootaxa 3794 (3), pp. 301-343 : 311-312

Agelas cervicornis ( Schmidt, 1870)

Fig. 3

Etymology from Latin, meaning deer horn.

Chalinopsis cervicornis Schmidt, 1870 : p. 60, pl. 5, Fig. 2 a. Agelas cervicornis ; Assman 2000: 37, pl. 4, Figs. B–E; Zea et al., 2009. Agelas longissima Pulitzer-Finali, 1986: 112 , Figs. 32, 34. Agelas sceptre ; Alcolado 1976: 5.

Agelas sceptrum ; Alcolado 2002: 61.

[Non: Agelas sceptrum ( Lamarck, 1815) , a valid species] Ectyon cylindricus Carter, 1883: 314 , Pl. XIII, Figs. 4 a–e. [Non: Agelas cylindricus ; Alcolado 1980: 3, 2002: 61, = Agelas sceptrum ] Agelas sp. 4; Pulitzer-Finali 1986: 114, Fig. 32; Lehnert & van Soest 1998: 83.

Material and distribution. Holotype not examined, apparently lost (van Soest, 2002). Schmidt’s description mentions the Antilles as the collecting locality without any further comments. The material examined here includes (but is not restricted to): Bahamas (INV– POR 929) and Jamaica (INV– POR 1003, 1010).

This species seems to be present only in the Bahamas ( Pulitzer-Finali 1986; Assmann 2000; Zea et al. 2009), Cuba ( Alcolado 1976; 2002) and Jamaica. Thus, we consider this species a Bahamian-Greater Antilles species. Our specimens were found from 14 to 30 m in depth, abundant between 23 and 28 m.

Description. Typically, this species has a long ( Fig. 3 A), erect ( Fig. 3 B) and cylindrical to subcylindrical ( Fig. 3 E, 3H) body, generally branched. Its dimensions are 3–6 cm in diameter and 50–100 cm long. The external colour in is dark brown, and internal colour cream. When dry, dark brown to dark greyish brown. The surface is smooth like velvet, but the general aspect of the body is uneven.

The oscules are numerous, small (± 1.5 mm) and evenly scattered, usually surrounded by a yellowish thin collar. Consistency is spongy, rigid, hard to tear or cut, tough in fresh, and hard when dry. The choanosome is dense, smooth and extremely compact with channels that do not exceed 3 mm in diameter.

The skeleton has plumoreticulate architecture, not evident in alcohol but more clear when dry. The main fibres are 50–150 µm in diameter, echinated and cored by 1–4 spicules per cross section. The secondary fibres are 40–60 µm in diameter, abundantly echinated, rarely cored. The acanthostyles are straight with 4–5 spines per whorl; length 65–135 (96±15.4) µm, width 1–13 (7±2.4) µm and 6–16 (10±2.2) whorls per spicule. Detailed lengths, widths and average number of whorls are shown in Table 2.

Remarks. This species was found in deep caves and on overhanging walls in Jamaica and in deep to medium slopes in the Bahamas. A superficial view could confuse this species with the clavaeformis (club shaped) form of A. dispar , but they differ by the solid choanosome in A. cervicornis and the cavernous choanosome in A. dispar . Agelas longissima ( Bahamas) and Agelas sp. 4 ( Jamaica) as described by Pulitzer-Finali (1986) and the material under the same name from Lehnert & van Soest (1998) belong to this species. Their small spicule size coincides with that of our own material from both localities (see Table 2). After several clarifying discussions, we agreed with Dr. P.M. Alcolado that his records of Agelas sceptrum from Cuba (erroneously called A. sceptre ), belongs to A. cervicornis , while what he called A. cylindricus belongs to A. sceptrum . Ectyon cylindricus Carter, 1883 is considered herein a junior synonym of A. cervicornis based on the original description.

The holotype of this species is apparently lost, as already stated by van Soest (2002), and our identification is based mainly on Schmidt’s (1870) description, and from description, specimens and photographs from Assman et al. (2001). Apart from the ZMA, we checked again unsuccessfully for the presence of the holotype at the Zoologisk Museum København in Copenhagen, where the other two holotypes ( A. conifera and A. clathrodes ) described in the 1870 Schmidt’s paper rest. We also queried without success the Natural History Museum in London, the Muséum National d'Histoire Naturelle in Paris, the National Museum of Natural History in Washington, and the Museum of Comparative Zoology in Cambridge ( USA).

In his 1870 paper Schmidt described three specimens and at the Zoologisk Museum København there are also three specimens, two representing the above-mentioned two species, and another one without specific designation (identified as A. citrina by us). Those three species are all typical for the Southwestern and Southern Caribbean, whereas A. cervicornis is common at Bahamian and Greater Antilles.

Figures

FIGURE 2. Photographs of Agelas dispar. A) Holotype. B) Bahamas massive specimen; note clustered collared oscules, and small circular oscules. C) Barbados round lobate specimen. D) Belize. E) Jamaica. F) San Andres Island (Colombia) flabellate specimen; note the keyhole-shaped oscules. G) Rosario Islands (Colombia) lobate specimen.

FIGURE 3. Photographs of Agelas cervicornis. Note the aspect if openings. A) Cylindrical. B) Rough surface detail. C) Subcylindrical ramifications. D) Multiple ramifications from specimens of the Bahamas. E) wide flattened. F) Cylindrical. G) Rough surface detail. H) Subcylindrical specimen from Jamaica.

FIGURE 4. Photographs of Agelas wiedenmayeri. A) Two tubes from the Bahamas; note the tube bud on the left tube. B) Five tubes from Belize, note two tiny tube buds at the common base. C) One tube from San Andres Island, Colombia. D) Keyholed tube covered by cianobacteria at Rosario Islands, Colombia.