Bellottia cryptica, Nielsen, Jørgen G., Ross, Steve W. & Cohen, Daniel M., 2009

Nielsen, Jørgen G., Ross, Steve W. & Cohen, Daniel M., 2009, Atlantic occurrence of the genus Bellottia (Teleostei, Bythitidae) with two new species from the Western North Atlantic, Zootaxa 2018, pp. 45-57 : 51-53

Bellottia cryptica , new species

( Figs. 4–7 )

Bellottia apoda: Ross & Quattrini (2007: 985, 996) Bellottia n. sp.: Ross & Quattrini (2008: 80)

Material examined (1 specimen, SL 42 mm): Holotype: NCSM 44451, SL 42, female, off southern Georgia, 30°48.74’N, 79° 37.96’W, st. JSL-04- 4485, 629 m, coll. S.W. Ross, 11 June 2004.

Condition of material. The holotype and only specimen was eviscerated for ecological studies, but is otherwise in good condition. Organs removed are archived with the specimen.

Diagnosis. Bellottia cryptica differs from its congeners by the following combination of characters: body slender (17.0 % SL at origin of anal fin), teeth small and pointed, caudal fin rays 7, origin of anal fin below dorsal fin ray 8, anterior gill arch with 5 long rakers, predorsal length 46.5 % SL, precaudal vertebrae 10, cleithrum with distinct spine just above base of pectoral fin, no spine on preopercular crest.

Similarity. Bellottia cryptica is most similar to B. robusta , in e. g. presence of spine on cleithrum and in fin ray and total vertebral counts, but differs by the more slender body (17.0 vs 17.5–23.0 % SL at origin of anal fin), origin of anal fin below dorsal fin ray 8 vs 10–15, precaudal vertebrae 10 vs 12 and no spine on preopercular crest vs 1 spine in B. robusta . It differs from B. galatheae by having 5–6 long rakers on anterior gill arch vs 4, and by having more rays in dorsal (92 vs 70–72), anal (84 vs 61) and pectoral (23 vs 19–20) fins. From B. apoda it differs by having 10 precaudal vertebrae vs 12, spine on cleithrum vs spine absent and 5–6 long rakers on anterior gill arch vs 3–4. From B. armiger it differs by having 7 caudal fin rays (vs 6), total vertebrae 49 (vs 45) and no spine on preopercular crest (vs spine present).

Description. The principal meristic and morphometric characters are shown in Table 1 .

Body short, highest near base of pectoral fin, completely covered with oval ca. 0.7 mm cycloid scales. Lateral line indistinct with anterior part apparently near dorsal margin of body. Head profile convex, cheek and gill cover scaled with rest of head naked. Mouth oblique with posterior part of maxilla vertically expanded ending just behind eye. Anterior nostril with low rim placed closer to upper lip than to posterior nostril. Small opercular spine strong and pointed, reaching beyond posterior margin of opercle. Lower edge of preopercle with four distinct spines, and no spine on preopercular crest ( Fig. 3 ). Origin of dorsal fin above tip of pectoral fin, anal fin origin at midpoint of fish. Pectoral fin placed on mid-body level with peduncle higher than long. A prominent spine on cleithrum just above base of pectoral fin. Anterior gill arch with 3–4 platelike rakers on upper branch, one long raker in the angle between the two branches and lower branch with 4–5 long rakers followed by 8–9 plate-like rakers. Longest gill filament about 1/3 of longest raker. Two short, broad pseudobranchial filaments.

Head pores: The loose and partly torn skin makes it difficult to observe the head pores. The following large, distinct pores were seen: three behind and three below the eye and four pores on the mandible. A few whitish sensory papillae distributed over the head.

Dentition: Head of vomer slightly curved with about 10 very small, blunt teeth in one row. Posterior half of palatines edentate, anterior half with small teeth in one row. Posterior half of dentaries edentate, anterior half with one row increasing to 4–5 tooth rows at symphysis with large and pointed teeth in outer row. Premaxillaries with posterior fourth edentate and further anteriorly small teeth in one row increasing to 4–5 rows at symphysis with larger and pointed teeth in outer row.

Axial skeleton (based on radiographs): Tips of neural and haemal spines thin and pointed. Anterior neural spine one third the length of second spine. Neural spines 2–8 depressed. Bases of neural spines 6–8 enlarged. Parapophyses present on vertebrae 7–10 and pleural ribs on vertebrae 4–9. Epipleural ribs indistinct.

Otolith ( Fig. 6 ): The 2 mm elongate sagittal otolith is 1.5 times as long as high and twice as high as thick. Dorsal and ventral rim rounded, vaguely pointed anteriorly. Sulcus undivided and 1/3–1/4 the length of the otolith. No osteal channel.

Coloration: Fig. 5 shows the holotype just after capture. The body is light brown, the margin of the vertical fins dark, the abdomen dark blue, the gill cover and side of head reddish brown and the eye is dark brown.

Biology. The general benthic habitat in the area where this specimen was collected consisted of a rugged, rocky ledge that was colonized by scattered hard corals (mostly Lophelia pertusa ), black corals, bamboo corals, sponges and hydroids. Bottom temperature was 7.8° C and salinity was 34.9 ppt. This specimen was swimming about 1.5–2 m above the ledge and was collected by suction sampler. A large amount of rotenone was spread in the area, and it seems likely this fish was escaping from that. We assume that this species is normally benthic and cryptic, similar to B. robusta . The stomach of this specimen was about one third full of unidentified crustacean parts.

Etymology. The specific name, cryptica , refers to its hidden nature.

Distribution ( Fig. 4 ). Known from a single specimen caught off southern Georgia, 30°48.74’N, 79°37.96’W, by suction-sampling from JSL at a depth of 629 m. We predict that it has a wider distribution along the slope between North Carolina and southeastern Florida.

Figures

FIGURE 3. Bellottia robusta. Paratype. USNM 394118. SL 34. Head spines: 1 — spine on cleithrum, 2 — opercular spine, 3 — preopercular spines, 4 - spine on preopercular crest.

FIGURE 4. Records of Bellottia robusta () and Bellottia cryptica (●). The number indicates the number of neighbouring stations.

FIGURE 5. Bellottia cryptica. Holotype. NCSM 44451. SL 42.

FIGURE 6. Bellottia cryptica. Holotype. Right sagitta: A—median view, B—ventral view.