Figure. Dorsal view of M. psychrophila, holotype, preserved, 84 mm ML, immature male, 59°26'S, 158°36'E. Photograph by M. Vecchione.
- Arms
- Arm suckers bear 12-18 sharp teeth on distal margin of inner ring . Click on an image to view larger version & data in a new window
Figure. Arm suckers of M. psychrophila. Left - Oral view of arm IV suckers, holotype, 84 mm ML and paratype, 145 mm ML. Drawing from Nesis (1977). Middle - Oral view of arm sucker, holotype. Photograph by M. Vecchione. Right - Oblique oral view of arm IV sucker, US NMNH cat. no. . Photograph by R. Young.
- Tentacles
- Tentacle whip-like; club circular in cross-section covering 40-60% of tentacle length (Nesis, 1977).
- Suckers number about 20 across club (Nesis, 1977); suckers number about 40 across in the NMNH specimen. Counts across the club are highly subjective.
- Density of suckers on club increases from base to mid-club (NMNH specimen).
- Average diameter of club sucker 0.15 mm (Nesis, 1977); NMNH specimen contains suckers of several sizes; 0.11 mm diameter is the largest and most common size.
- Head
- Bridles to the funnel apparently with a deep pocket between them.
- Mantle
- Mantle and other skin, apparently, without tubercules. Nesis did not mention tubercules and no trace of tubercules is present in the skinned squid we examined.
- Fins
- Fins approximately circular in outline (Nesis, 1977).
- Fin length 67 % of ML, width 60-70% of ML (Nesis, 1977).
- Photophores
- Eyelid with small (0.3 mm) photophore (Nesis, 1977).
- Pigmentation
- Bright purple-carmine in fresh squid; dark purple after fixation (Nesis, 1977).
- Measurements and counts
Figure. Club of the NMNH specimen of M. psychrophila. Left - Oral view of the club. Right - Oral view of club segment showing suckers of different sizes. Arrows point to small suckers. Photographs by R. Young. Photograph by M. Vecchione.
Scanning electron micrographs of the suckers can be found here.
Figure. Eyelid photophore of M. psychrophila. Left - Lateral view of portion of head; arrow points to eyelid photophore, NMNH no. 817317. Right - Similar view, different squid, with eyelid photophore covered by dense pigment. Damaged window to the photophore and the associated chromatophores still visible. Photographs by R. Young.
| Squid | Holotype | Paratype | Paratype | Paratype | NMNH # 817317 | NMNH 884836 |
| Sex | Imm. male | Adult male | Imm. male | Imm. male | -- | Imm. male |
| Mantle length | 84 | 143 | 124 | 88 | 105 | 85 |
| Mantle width | 21 | 22 | 20 | 27 | -- | 22 |
| Fin length with tail | 68 | 66 | 66 | 61+ | -- | -- |
| Fin length without tail | 62* | -- | -- | -- | 59 | 54 |
| Fin width | 70 | 61 | 71 | 63 | 72 | 59 |
| Head width | 19 | 15+ | 21 | 22 | 28 | -- |
| Eye diameter | -- | -- | -- | -- | 19 | 14 |
| Arm I length | 42 | 38 | 44 | 45 | 40 | 34 |
| Arm II length | 58 | 50 | 56 | 62 | 59 | 46 |
| Arm III length | 60 | 44 | 51 | 53 | 53 | 42 |
| Arm IV length | 159 | 105 | 119 | 86+ | 106 | 91.5 |
| Eyelid photophore length/width | 0.3* | -- | -- | -- | 0.5 / 0.35 | -- |
| Tentacle length | 202 | 129 | -- | 156 | 200 | 145 |
| Club length (% of tentacle length) | 41-44% | 83% | -- | 62% | 70+% | 69% |
| Club sucker diam. | 0.15* | -- | -- | -- | 0.8-0.11 | -- |
| Arm sucker diam. | -- | -- | -- | 1.2 | -- |
*Measurement mentioned by Nesis in text, presumably refers to holotype.
Type-series measurements above are from Nesis (1977).
