Histology and teratology of pink salmon larvae near the time of emergence from gravel substrate in the laboratory


Journal Article

During salmonid larval development, emergence from gravel substrate is a major event marked by final yolk absorption and transition to exogenous feeding. The gross and histological changes associated with this fundamental biological process were investigated in pink salmon (Oncorhynchus gorbuscha) 4 weeks before emergence (alevins), at emergence (swim-up fry), and 2 weeks after emergence with or without exogenous feeding. Larvae were derived from artificially spawned eggs reared in gravel-filled incubators in the laboratory. Less than 1% of emergent larvae had gross lesions. These included opercular hypoplasia or dysplasia (semioperculum), spinal anomalies (lordosis and kyphosis), conjoined twins, and ophthalmic dysplasia. Apoptosis, or programmed cell death, was a common cellular change, and several cell types were involved: (i) intragonadal supporting cells, (ii) gastric submucosal gland epithelial cells, and (iii) midventral skin cells. Semiquantitative scores for apoptosis were usually highest in pre-emergent larvae and lowest in postemergent larvae. Larvae that were not fed during the first 2 weeks after emergence had slightly higher scores for apoptosis and hepatocellular megalocytosis than did fed controls.

Full Text

Duke Authors

Cited Authors

  • Marty, GD; Heintz, RA; Hinton, DE

Published Date

  • January 1, 1997

Published In

Volume / Issue

  • 75 / 6

Start / End Page

  • 978 - 988

International Standard Serial Number (ISSN)

  • 0008-4301

Digital Object Identifier (DOI)

  • 10.1139/z97-119

Citation Source

  • Scopus