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Larvae Information Summary for
Lepisosteus osseus
| Main Ref: | Jones, P.W., F.D. Martin and J.D. Hardy Jr. 1978 | |||
Yolk-sac larvae
| max | min | mod | Ref. | |
| Length at birth (mm) | 10 | 8 | ||
| Preanal L. % TL |
| Place of development | in close association with substrate | |||
| Larval area | Mid-Atlantic Bight | |||
| Yolk-sac | ovoid pigmented | Ref: | ||
| Yolk | unsegmented | Oil globules | ||
| Rows on tail | dorsal + ventral row | |||
| Other melanophores on tail | no other melanophores | |||
| Melanophores on head + trunk | melanophores on head + trunk | |||
| Mouth open, more or less rhomboidal, and preceded by papillate suctorial disc at 11 mm, becoming narrow slit accompanied by elongation of preoral region into short snout with terminal, suctorial disc at 15 mm. At 21 mm, snout increased greatly in length, and lower jaw elongated (Ref. 38415). Eye poorly developed at hatching, choroid fissure retained to at least 11 mm. Dorsal, anal, and caudal fins indicated by dense pigment in finfold at 11 mm, becoming even more dense at 15 mm; pectorals forming as prominent, vertically projecting, longitudinal ridges on surface of yolk sac at 11 mm; pectoral insertions oriented more or less horizontally with body and covered by large opercular flap at 15 mm; ventrals visible as small longitudinal projections near posterior end of yolk sac at 15 mm; urostyle oblique by 2nd day. Pigmentation: Body colorless, transparent; yolk sac opaque bluish gray at hatching. "Somewhat later" upper edge of yolk sac and surface of alimentary canal with small melanophores toward head region and on sides; by 5th day, entire body with melanophores except yellowish gray venter. By 11th day, melanophores most numerous above eye, in dorsal region, in dark band from upper margin of yolk to tail, and in region of future vertical fins. White areas completely enclosed in black, developed dorsally and ventrally in caudal region; fleshy lobes of pectorals and outer edge of gill cover bluish. | ||||
Post larvae
| Striking feature | teeth clearly visible | |||
| Striking shape lateral | normal (not striking) | dorsal | ||
| Striking feature | teeth clearly visible | |||
| Shape of gut | ||||
| Gas bladder early | late | |||
| Spinal armature early | late | |||
| Pigmentation early | ||||
| Rows on tail | dorsal row | |||
| Other melanophores on tail | no other melanophores | |||
| Melanophores on head + trunk | melanophores on head + trunk | |||
| Melanophores on head + trunk | melanophores on trunk | |||
| At about 20 mm, teeth evident; suctorial disc reduced to a swelling on extremity of elongate upper jaw, disappearing by about 25-40 mm. Incipient rays of dorsal, anal, pectoral, and caudal fins evident by about 20 mm; pelvic rays evident at about 23-24 mm, although pelvics may develop before pectorals in some cases. Notochord produced posteriorly into an elongate fleshy filament above caudal at about 23 mm. Preanal finfold still evident at 41 mm. Pigmentation: At about 20 mm, dorsal region mottled with broad, irregular patches of brown and a heavy black line extends from back of eye to tip of tail. At 41 mm, various shades of brown banded irregularly on sides with white. | ||||
| 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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