Characella poecillastroides, Van Soest & Meesters & Becking, 2014

Van Soest, Rob W. M., Meesters, Erik H. W. G. & Becking, Leontine E., 2014, Deep-water sponges (Porifera) from Bonaire and Klein Curaçao, Southern Caribbean, Zootaxa 3878 (5), pp. 401-443 : 410-411

publication ID

https://dx.doi.org/10.11646/zootaxa.3878.5.1

publication LSID

lsid:zoobank.org:pub:11145FA0-2CB5-460A-B7A6-9A634C778982

persistent identifier

https://treatment.plazi.org/id/170EACF1-9FC7-47C6-9904-8CE6DFCEF220

taxon LSID

lsid:zoobank.org:act:170EACF1-9FC7-47C6-9904-8CE6DFCEF220

treatment provided by

Felipe

scientific name

Characella poecillastroides
status

new species

Characella poecillastroides new species

Figures 6a–d View FIGURE 6 , 7a–e View FIGURE 7

Material examined. Holotype: RMNH Por. 9247, Caribbean Netherlands, Bonaire, Curoil Dock (Dive 3), 112.137°N 68.286°W, on a coral rock wall at 168 m, coll. L.E. Becking & E. Meesters, field nr. BON3/ BDR031 , 31 May 2013.

Description. Thickly massive, folded plate ( Figs. 6a–c View FIGURE 6 ) of 2–4 cm thick and approximately 20–40 cm in lateral expansion. A fragment of 8 x 2 x 2.5 cm was preserved. Rough/hispid surface due to protruding spicules, which cause strong accumulation of sediment. No oscules visible. Color beige alive underneath greyish sediment layer, white-beige after preservation. Consistency hard, rough, but can be torn rather easily.

Skeleton. Radiate skeleton of long oxeas ( Fig. 6d View FIGURE 6 ), with a relatively low presence of calthrops-like shortshafted triaenes. Microxeas form a rather dense cover at the surface and are abundantly strewn in the choanosome.

Spicules. Calthrops, oxeas, amphiasters, microxeas.

Calthrops-like short shafted triaenes ( Fig. 7a View FIGURE 7 ), cladi straight or curved, in a large size range, cladomes 400- 598 - 800 µm, cladi 200– 345 –500 x 20– 27 – 30 µm.

Oxeas ( Fig. 7b View FIGURE 7 ), smooth, usually somewhat curved, 2600– 3120 –3800 x 35– 46.5 – 62.5 µm.

Amphiasters ( Fig. 7c View FIGURE 7 ), rugose/spined all over, 10– 17 – 25 µm, with 10–16 rays of 2.5– 6 – 10 µm long.

Microxeas, microspined/rugose, in two size classes, larger ones (1, Fig. 7d, 7d View FIGURE 7 1 View FIGURE 1 ), gently curved and with tapering sharp ends, 170– 232 –275 x 4– 7 – 10 µm, and short ones (2, Fig. 7e, 7e View FIGURE 7 1 View FIGURE 1 ), abruptly curved and/or centrotylote, 25– 37 –45 x 2–3 µm.

Ecology and distribution. The holotype was collected on a carbonate rock wall just below the mesophotic zone off Bonaire.

Etymology. The name refers to the plate-like shape which is unusual in the genus Characella , but is characteristic for the related genus Poecillastra .

Remarks. The new species is assigned to Characella because of the occurrence of two microxea categories and the predominance of amphiaster microscleres (cf. Cárdenas & Rapp 2012). The habit resembles that of a Poecillastra , but that genus has a single microxea category and diverse streptasters including spirasters. Barbados Poecillastra sollasi sensu Van Soest & Stentoft, 1988: 36 (not sensu Topsent 1890) also has this habit, but differs in having metasters and spirasters, next to amphiasters. This Barbados material was discussed by Cárdenas & Rapp (2012), who pointed out that the species appears intermediate between Poecillastra and Characella in having two sizes of microxeas next to diverse streptasters. Apparently, habit is not a good marker for the two genera, which have been demonstrated to be distinct genetically ( Cárdenas et al. 2011). Characella aspera Sollas, 1886 as reported by Van Soest & Stentoft (1988: 38) from Barbados appears close in spiculation to C. poecillastroides n. sp., but is radically different in habit (see Table 2 View TABLE 2 and Figs 21a View FIGURE 21 1 View FIGURE 1 , 21a View FIGURE 21 2 View FIGURE 2 ). Several specimens were collected during the present submarine dives (BDR027 and 036).

RMNH

National Museum of Natural History, Naturalis