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Larval Development of the Northern Hog Sucker (Hypentelium nigricans), from the Susquehanna River
Author(s) -
Buynak Gerard L.,
Mohr Harold W.
Publication year - 1978
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1978)107<595:ldotnh>2.0.co;2
Subject(s) - sucker , larva , biology , fishery , zoology , ecology
Northern hog sucker (Hypentelium nigricans) eggs hatched in 10 days at a mean temperature of 17.4 C. Newly hatched larvae measured from 9.0 to 10.6 mm total length (TL) with a mean of 10.0 mm (standard or notochord length ranged from 8.7 to 10.1 mm with a mean of 9.6 mm). The newly hatched larvae were melanophore‐free and had heads that were decurved over a bulbous yolk sac. They had slightly upturned urostyles, pectoral fin buds, and incomplete mouths. Throughout the protolarval phase, they remained relatively melanophore‐free. In mesolarvae 15.8 mm TL, an almost triangular patch of melanophores was apparent on the occipital region and was separated from more anterior pigmentation by a melanophore‐free area between the eyes. Similar pigmentation was found in metalarvae. Fin rays were visible in caudal, pectoral, dorsal, anal, and pelvic fins by 12.0, 12.6, 15.8, 17.8, and 17.8 mm TL, respectively. Transformation to mesolarval phase occurred by 12.0 mm TL, to metalarval phase by 19.8 mm TL, and to the juvenile period by 27.8 mm TL. Useful characteristics for distinguishing sucker larvae in the Susquehanna River are flexed urostyles in protolarvae, size, and pigmentation patterns.