Claviderma crassum, Ivanov & Scheltema, 2008

Ivanov, Dmitry L. & Scheltema, Amélie H., 2008, NMR solution structures of KAP- 1 PHD finger-bromodomain, Zootaxa 1885, pp. 1-60 : 16-19

Claviderma crassum n. sp.

( Figures 1D , 9 , 10 , 13C–E , 25 ; Table 4a)

Type material: Holotype USNM 1112621 . Paratypes: USNM; TAMU ; ZMUM Le1–179 ( RV Knorr Cruise 25, station 297, 5 specimens) .

Type locality: Guiana Basin, 08°04.2'N, 54°21.3'W, 1,000 m ( RV Knorr Cruise 25, station 295, 28.02.1972) .

Material examined ( Table 4a): Guiana Basin, 2 stations, 32 specimens.

Diagnosis: Body large for a Prochaetodermatidae , both length (to 7.3 mm) and trunk width (to 2.5 mm), posterium short, usually less than ½ trunk length; trunk but not shank sclerites adpressed, at 45º to longitudinal body axis; shank sclerites long, extending onto fringing sclerites. Oral shield sclerites in 5 rows, not obvious. Trunk sclerites as in Cl. amplum except longitudinal striations distinct in transmitted light, ventral sclerites shorter relative to dorsal sclerites.

Etymology: L. crassus, -a, -um = stout.

Description: External appearance ( Figs 1D , 9A, B ): Stout, posterium length less than 1/2 trunk length, posterium/trunk index 0.29–0.59, holotype length 7.3 mm, anterium 0.3 mm, trunk 4.5 x 2.5 mm, shank 1.7 x

0.9 mm, knob 0.8 mm, posterium/trunk index 0.56; trunk sclerites adpressed, diverging from ventral midline, almost convergent along dorsal midline; shank sclerites raised, long, extending onto knob. Oral shield 0.28 mm in height. Sclerites similar to those of Cl. amplum .

Collections in the Guiana Basin were made with an epibenthic sled and covered a swath perhaps a couple of kilometers long, so strict sympatry of the two species is not known. Cl. crassum may be endemic to the Guiana Basin. Sclerites of both species are most similar to the equally large (to 8.0 mm) but most commonly smaller (4–6 mm) eastern Atlantic, longer tailed species Cl. gladiatum (Salvini-Plawen) .

Figures

FIGURE 1. Holotypes of new Prochaetodermatidae species in the western Atlantic Ocean south of 35°N. A. Chevroderma cuspidatum, Gulf of Mexico. B. Claviderma amplum, Gulf of Mexico. C. Spathoderma compactum, Argentine Basin. D. Claviderma crassum, Guiana Basin. E. Spathoderma bulbosum, Gulf of Mexico. F. Claviderma mexicanum, Gulf of Mexico. G. Prochaetoderma gilrowei, Gulf of Mexico. H. Niteomica captainkiddae, Gulf of Mexico. I. Spathoderma quadratum, Gulf of Mexico.

FIGURE 9. Claviderma crassum n. sp., Guiana Basin. A, F. Holotype (RV Knorr Cruise 25 station 295). B–E. Paratype, type locality. A, B. Entire. C. Oral shield sclerites in situ. D. Radula tooth and central plate. E. Jaw. F. Trunk sclerites.

FIGURE 10. Claviderma crassum n. sp., sclerites from same paratype as Figure 8B. A. Oral shield. B. Dorsal to oral shield. C. Anterium. D. Ventral anterior trunk. E. Dorsal anterior trunk. F. Ventral mid-trunk. G. Dorsal mid-trunk. H, J. Shank. I, K, L, M. Knob. N. Fringe. (Lateral view of trunk sclerites similar to that of Cl. compactum, Fig. 8L.)

FIGURE 13. Trunk sclerites of Claviderma n. spp. paratypes (SEM). A, B. Cl. compactum, Argentine Basin, type locality; B showing fine striations not visible in A and subtriangular cross-section of thick sclerite. C–E. Cl. crassum, Guiana Basin, type locality; C, E showing long blade and sharp striations, enlarged in D; E showing curved sclerite. F. Cl. mexicanum, Gulf of Mexico, type locality; sclerites as they appear in situ.

FIGURE 25. Distribution of Prochaetodermatidae species outside the Gulf of Mexico but restricted to the western Atlantic south of 35ºN.