Gonatus steenstrupi: Description continued

1. Arms
   1. Arm formula: II>IV>II>I
   2. Armature in four series: arms I-III with 2 medial series of hooks and 2 marginal series of suckers; arm IV with suckers only.
   3. Arm suckers with about 23 teeth and cusps; pointed teeth distally grading to very small cusps proximally.
   4. Suckers of medial series of arms IV largest.
   

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   Figure. Oral views of large arm suckers of G. steenstrupi. Left - Marginal sucker of arm III. Right - Arm IV sucker. Drawings from Kristensen (1981).

2. Tentacles
   1. Primary locking-apparatus with 4 thick ridges with 5 medial suckers and alternating knobs.
   2. Largest suckers of ventral-marginal series with 23 teeth and cusps; long pointed teeth on distal margin of inner ring grading to small teeth or cusps proximally.These suckers slightly smaller than largest arm suckers.
   3. Dorsal margin of tentacular stalk with series of alternating suckers and pads along most of stalk length; distal five suckers each with additional small, thick ridge.
   4. Ventral margin of tentacular stalk with single series of suckers along most of stalk length. Number of suckers slightly fewer than of those in dorsal series.
   

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   Figure. Oral view of large sucker from ventral-marginal zone of club of G. steenstrupi. Drawing from Kristensen (1981).

3. Head
   1. Beaks
      1. Upper beak with long, strong, heavily pigmented rostrum; jaw angle obtuse; shoulder nearly straight with small swelling near jaw angle and at opposite end; dorsal crest curved with saddle of pigment.
      2. Lower beak with strong, pointed rostrum; jaw angle clearly obtuse; much of wing unpigmented; most of lateral wall and crest pigmented.
   

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   Figure. Side views of beaks of G. steenstrupi. Left - Upper beak, 68 mm GL. Right - Lower beak, 57 mm GL. Drawings from Kristensen (1981).

   2. Radula
      1. Radula with five series of teeth
         


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Figure. Transverse row of teeth from radula of G. steenstrupi, 57 mm ML. Drawing from Kristensen (1981).

4. Measurements and counts

   Sex	Male Holotype	Male	Male	Female	Female
   Gladius length	94 mm	68 mm	57 mm	65 mm	42 mm
   Head length	22	15	16	19	10
   Head width	18	14	13	16	11
   Fin length	45	31	30	37	23
   Fin width	55	42	39	46	36
   Arm I, length	44	29	27	38	21
   Arm II, length	50	33	32	45	25
   Arm III, length	53	34	32	47	38
   Arm IV, length	50	32	32	46	26
   Club length	22	15	15	19	11
   Funnel cart. length	13	10	09	10	08
   Nuchal cart. length	12	08	08	07	07
   1/2 Arm I count	35	32	32	34	29
   1/2 Arm II count	34	30	34	37	32
   1/2 Arm III count	35	32	37	39	27
   1/2 Arm IV count	55	51	52	58	50
   Club sucker count	220	212	200	217	199
   Median stalk sucker count	159	133	100	89	102
   Dorsal stalk sucker count	85	77	84	63	57
   Ventral stalk sucker count	81	72	56	76	53

Comments

The above description is taken from Kristensen (1981) and, except for the table of measurements, is based on the holotype.