Onychoteuthis borealijaponicus: Description continued

1. Arms
1. Arms II-IV subequal; Arms I smallest.
2. Largest suckers of arms I-III subequal; largest suckers of arms IV smaller (see relative sizes of suckers in drawing at right. A-D = largest suckers of arms I-IV respectively).


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Figure. Oral view of largest arm suckers of O. borealijaponicus. A-D = suckers of arms I-IV respectively, 81 mm ML, off southern California. Drawing from Young (1972).

2. Tentacles
1. Club with 14-16 terminal-pad suckers.
2. Carpal locking apparatus with 8-11 suckers.
3. Pigmentation absent proximal to carpus on mid-oral and ventro-oral edge.
4. Distal ventral-hooks with spike (top drawing below).


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Figure. Top - Oral view of hook number 9 of ventral hook-series of O. borealijaponicus. Drawing from Young (1972). Bottom - Oral view of preserved tentacular club of O. borealijaponicus, 175 mm ML, immat. female, 45°N, 175°W. Photograph by R. Young.

3. Gladius
1. Gladius similar to other members of the genus.


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Figure. Ventral view of the gladius of O. borealijaponicus with cross-sections, 325 mm GL. Drawing from Toll (1982).

4. Measurements and counts

Sex	Female, immat.	Male, immat.	Male, immat.	Female, immat.	Female, immat
Mantle length	69	73	80	163	175
Mantle width	15	15	20	34	44
Fin length	38	43	46	93	98
Fin width	47	56	64	106	117
Club length	18 / 18	23 / 23	29 / 29	54 / 53	57 / 60
Club hooks, number	26 / 24	25 / 26	25 / 25	27 / 26	26 / 26
Club terminal-pad suckers, number	14 / 14	16 / 14	14 / 15	16 / 15	15 / 16
Club carpal suckers, number	10 / 10	9 / 8	10 / 10	10 / 11	10 / 9
Arms I, length	20 / 21	22 / 23	34 / 35	- / -	61 / 61
Arms II, length	27 / 25	31 / 31	43 / 43	74 / 77	75 / 74
Arms III, length	25 / 26	31 / 28	42 / 41	73 / 73	71 / 75
Arms IV, length	25 / 24	32 / 30	44 / 44	77 / 76	77 / 76
Anterior visceral photophore, length/width	1.5 / 0.9	1.9 / 0.8	1.8 / 1.3	1.9 / 1.5	1.9 / 2.3
Posterior visceral photophore, length/width	1.9 / 1.0	2.3 / 1.3	2.6 / 1.8	5.1 / 3.2	4.0 / 2.6

Measurements in mm; right / left

References

Toll, R.B. 1982. The comparative morphology of the gladius in the Order Teuthoidea (Mollusca: Cephalopoda) in relation to systematics and phylogeny. PhD. Dissertation, University of Miami, 390 pp.

Young, R. E. 1972. The systematics and areal distribution of pelagic cephalopods from the seas off Southern California. Smithson. Contr. Zool., 97: 1-159.