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Larvae Information Summary for
Bathylagus pacificus
| Main Ref: | Moser, H.G. and E.H. Ahlstrom 1996 | |||
Yolk-sac larvae
| max | min | mod | Ref. | |
| Length at birth (mm) | 4 | 3.5 | ||
| Preanal L. % TL |
| Place of development | planktonic | |||
| Larval area | Northeastern Pacific (California Current region); Northwestern Pacific (Japan) | |||
| Yolk-sac | Ref: | |||
| Yolk | segmented | Oil globules | more than one oil globule | |
| Rows on tail | no rows | |||
| Other melanophores on tail | tail with single melanophore | |||
| Melanophores on head + trunk | melanophores on trunk | |||
| Pigmentation: at notochord tip; in late yolk-sac larvae 2 (large) laterally at juncture of gut and trunk, 1 at midbody and the other at posterior region of hindgut. | ||||
Post larvae
| Striking feature | stalked eyes | |||
| Striking shape lateral | eel-like | dorsal | ||
| Striking feature | stalked eyes | |||
| Shape of gut | tube-like | |||
| Gas bladder early | late | |||
| Spinal armature early | no spines | late | no spines | |
| Pigmentation early | ||||
| Rows on tail | no rows | |||
| Other melanophores on tail | no other melanophores | |||
| Melanophores on head + trunk | melanophores on head + trunk | |||
| Pigmentation late | ||||
| Rows on tail | no rows | |||
| Other melanophores on tail | no other melanophores | |||
| Melanophores on head + trunk | melanophores on head + trunk | |||
| Urostyle region early | pigmented | late | unpigmented | |
| Peritoneum | with row of melanophores | |||
| Pectorals | normal without melanophores | |||
| Pelvics | normal (i.e. small or absent) without melanophores | |||
| Stalked eyes with stalk length averaging 28% HL in preflexion stage and 33% in flexion stage, decreasing to 7-11% inlate postflexion and transformation stages; 2 large blotch-like lateral melanophores with 1-2 smaller ones on gut between; low dorsal fin ray count (8-13) and relatively high anal fin ray count (15-25). Pigmentation: large isolated melanophores; early larvae have large lateral blotch at midbody and another posteriad, becoming located on trunk with development; third blotch forms midway between and below other two blotches; fourth lateral trunk blotch forms in some late larval specimens between pectoral fin and large midbody blotch; other melanophores form lateral to liver and terminal section of gut; also isthmus/thoracic, dorsal gut, caudal, and two bands on body (early). Sequence of fin development: caudal, anal, dorsal and pectorals and pelvics. | ||||
| L 1st feeding | Ref. | Months of presence of larvae | ||||
| max | Jan | Feb | Mar | Apr | ||
| min | May | Jun | Jul | Aug | ||
| mod | Sep | Oct | Nov | Dec | ||
| Water parameters Metric characters |
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