Bothrocara nyx

description

Description: Vertebrae 18 (17 - 19) + 94 (90 - 98) = 112 (108 - 116); dorsal-fin rays 109 (103 - 112); anal-fin rays 93 (89 - 99); caudal-fin rays 10; pectoral-fin rays 13 (12 - 15); vomerine teeth 2 (0 - 3); palatine teeth 10 (0 - 10); gill rakers 6 (5 - 7) + 21 (17 - 21) = 27 (23 - 27); pseudobranchial filaments 9 (7 - 10). Following measurements in percent SL: head length 19.4 (17.6 - 20.3); head width 7.8 (5.6 - 8.3); head depth 8.1 (8.8 - 11.4); pectoral-fin length 12.5 (9.9 - 14.4); predorsal length 17.9 (17.0 - 21.4); preanal length 33.9 (32.5 - 38.0); body height 8.5 (8.8 - 10.8); gill-slit length 9.1 (9.1 - 12.6). Following measurements in percent head length (HL): head width 40.1 (27.7 - 43.2); head depth 41.7 (43.4 - 59.6); upper jaw length 40.1 (36.4 - 43.5); pectoral-fin length 64.5 (49.8 - 72.4); pectoral base 9.1 (8.0 - 14.7); snout length 23.1 (17.8 - 26.0); eye diameter 27.0 (24.2 - 34.7); gill-slit length 46.9 (49.7 - 64.6); interorbital width 9.8 (8.4 - 16.4); interpupillary width 26.7 (22.0 - 34.6); caudal-fin length 22.1 (13.7 - 25.4). Pectoral-fin base / length ratio: 0.14 (0.14 - 0.22). Body relatively long and compressed. Skin thin and delicate, particularly

Bothrocara nyx: a new species of eelpout (Perciformes: Zoarcidae) from the Bering Sea.

diagnosis

Diagnosis: A species of Bothrocara as defined by Anderson (1994), with vertebrae 17 - 19 + 90 - 98 = 108 - 116; pectoral-fin rays 12 - 15; vomerine teeth 0 - 3; gill rakers moderately long, 23 - 27; snout short, less than eye diameter; median occipital pore present; lateral line not visible on body; interior of mouth darkly pigmented.

Bothrocara nyx: a new species of eelpout (Perciformes: Zoarcidae) from the Bering Sea.

discussion

Remarks: Anderson (1994) recognized seven species of Bothrocara: B. alalongum (Garman), B. brunneum (Bean), B. elongatum (Garman), B. hollandi (Jordan and Hubbs), B. molle Bean, B. pusillum (Bean), and B. tanakae (Jordan and Hubbs). Among its congeners, B. nyx is most commonly collected with B. brunneum on the Bering Sea slope. Although B. brunneum attains a much larger maximum size than B. nyx, the two species can be difficult to differentiate at small sizes ( 800 m). Bothrocara pusillum is similar to B. nyx in having a short snout and small maximum size (approximately 200 mm SL). However, B. pusillum has fewer and shorter gill rakers (12 - 15 vs. 23 - 27, Fig. 3), fewer pseudobranchial filaments (4 - 7 vs. 7 - 10), more pectoral-fin rays (15 - 17 vs. 12 - 15), and a higher pectoral-fin ratio (0.20 - 0.31 vs. 0.14 - 0.22) than B. nyx. Bothrocara molle is also known throughout the North Pacific, but generally has a higher vertebral count (113 - 118 vs. 108 - 116), a more posteriorly placed dorsal fin (anterior pterygiophore usually in fourth interneural space vs. second interneural space), and a lower gill-raker count (18 - 24 vs. 23 - 27). Bothrocara molle also attains a much lar

Bothrocara nyx: a new species of eelpout (Perciformes: Zoarcidae) from the Bering Sea.

distribution

Distribution: This species is known only from the upper continental slope of the eastern Bering Sea, where it has been captured at depths ranging from 790 to 1508 m (Fig. 4).

Bothrocara nyx: a new species of eelpout (Perciformes: Zoarcidae) from the Bering Sea.