Coelorinchus, Giorna, 1810

Iwamoto, Tomio, Nakayama, Naohide, Shao, Kwang-Tsao & Table, Hsuan-Ching Ho, 2015, Synopsis of the Grenadier Fishes (Gadiformes; Teleostei) of Taiwan, Proceedings of the California Academy of Sciences 62 (3), pp. 31-126 : 48-49

Key to the Species of Coelorinchus in Taiwan

1a. Light organ with two widely separated, usually blackish fossae, one immediately behind isthmus, the second immediately before anus, both connected by a medioventral line; anus/urogenital opening immediately before A origin; ventral snout surface with a series of overlapping scales at anterolateral margin.................................................. 2

1b. Light organ variously developed, from scarcely visible to prominent with a single large fossa between or slightly anterior to V bases; anus/urogenital opening immediately before or separated by several scale rows from A origin; no overlapping series of scales ventrally on anterolateral snout margin......................................................... 9

2a. Underside of head behind mouth mostly scaled......................... C. formosanus

2b. Underside of head essentially wholly naked (tiny isolated scales sometimes present above posterior angle of mouth and on preopercle)........................................ 3

3a. Anterior rays of 2D about equal in height to those of A.............................. 4

3b. Anterior rays of 2D decidedly shorter than those of A............................... 7

4a. Body with prominent dark longitudinal stripes.............................. C. hubbsi

4b. Body with prominent saddles or completely lacking body markings................... 5

5a. No body markings; snout rather short, broad, depressed, 39–44% HL........ C. brevirostris

5b. Prominent saddle marks on body; snout 36–50% HL............................... 6

6a. 1D with elongated spinous ray; BR membrane dusky to pale................ C. cingulatus

6b. No elongated spinous ray in 1D; BR membrane dark to black............... C. fuscigulus

7a. Body covered with bold vermiculations and blotches, more or less aligned in 2 or 3 longitudinal rows; origin of 2D slightly before vertical through A origin; 1D-2D interspace about equal to length base of 1D........................................... C. multispinulosus

7b. Body immaculate or with irregular, sometimes faint, markings; origin of 2D about on same vertical as, or somewhat behind, A origin; 1D-2D interspace greater than length base of 1D.. 8

8a. Gular and branchiostegal membranes heavily peppered with black pigmentation, chest region relatively dark, underside of head covered with tiny black sensory papillae; spinules on body scales broadly triangular, in irregular, somewhat quincunx pattern.......... C. kamoharai

8b. Underside of head faintly dusky to immaculate, chest region light dusky, sensory papillae on underside of head scattered and inconspicuous; spinules on body scales weak, small, in 6–14 somewhat parallel to divergent rows................................. C. longissimus

9a. Snout relatively blunt, not acutely pointed; a distinct curve in anterior portion of suborbital shelf; anus about midway between A origin and base of outer V rays, preceded by large black fossa of light organ................................................ C. macrochir

9b. Snout acutely pointed in lateral view; suborbital shelf lacking distinct curve anteriorly; anus closer to A origin than to base of outer V rays, fossa of light organ present or absent.... 10

10a. A blackish round blotch above P; anus removed from A by several scale rows; large fossa of light organ extending forward between V bases.................................. 11

10b. No blackish blotch above P; anus immediately before or removed from A origin; light organ situated posterior to V bases................................................. 12

11a. Black blotch above P large, spanning 5–7 diagonal rows of scales; gular and branchiostegal membranes black; height 1D 45–54% of pre-vent length................. C. kishinouyei

11b. Black blotch above P small, spanning 3 or 4 diagonal scale rows; gular and branchiostegal membranes pale or whitish; height 1D 67% of pre-vent length.............. C. cf. notatus

12a. Underside of head entirely or almost entirely naked (underside of head completely naked except for ventral portion of preopercle in C. hexafasciatus )....................... 13

12b. Underside of head scaled (underside of snout naked in C. leptorhinus , but posteriorly head scaly)................................................................... 16

13a. Dark saddles on trunk and tail.................................... C. hexafasciatus

13b. No saddle marks on body................................................... 14

14a. Spinules on body scales below 2D with 3–5 divergent rows of strong, triangular spinules, middle row higher than lateral rows...................................... C. productus

14b. Spinules on body scales below 2D with 4–11 somewhat parallel to divergent, sharply crestlike rows of narrow, triangular spinules......................................... 15

15a. Scales of median nasal ridge 9–12, spinule rows directed laterally and posteriorly only................................................................... C. anatirostris

15b. Scales of median nasal ridge 6–8, with spinules radiating in all directions.... C. asteroides

16a. Prominent saddle markings on body; snout tip lacking sharp terminal scute....... C. sheni

16b. No saddle markings on body; a sharp terminal snout scute present................... 17

17a. Underside of snout naked (head scaly from above mouth posteriorly)....... C. leptorhinus

17b. Underside of snout and head fully scaled....................................... 18

18a. Anterolateral margin of snout incompletely supported by bone...................... 19

18b. Anterolateral margin of snout completely supported by bone....................... 20

19a. Body scales with 4–6 parallel rows of strong, high, usually broad-based (i.e., large lateral buttresses) spinules; scales between occipital ridges and on underside of head mostly with one spinule row...................................................... C. parallelus

19b. Body scales with 3–8 somewhat parallel to broadly divergent rows of spinules; scales between occipital ridges with 1–5 spinule rows, on underside of head with 1–3 rows... C. divergens

20a. Light organ visible only as crescent-shaped area of perianal ring, no separate fossa; most scales between occipital ridges with a single row of spinules............... C. japonicus

20b. Light organ with short fossa extending anteriorly almost to or between V fins; scales between occipital ridges with 2–5 rows of spinules...................................... 21

21a. Nasal fossa naked; large strong spinules on body scales in 3 divergent rows; scales between occipital ridges with a single row of spinules........................... C. cf. spinifer

21b. Nasal fossa usually scaled anteroventrally, seldom naked; spinules on body scales in 4–6 (3–7) divergent rows; scales between occipital ridges with multiple rows (usually 2–4) of spinules........................................................................ 22

22a. Length 1D base 1.2 times into 1D-2D interspace; nasal fossa densely scaled anteroventrally......................................................... C. cf. macrorhynchus

22b. Length 1D base 1.3–2.0 times into 1D-2D interspace; nasal fossa rather sparsely scaled on anteroventral surfaces, sometimes naked.................................. C. smithi