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Types and occurrence of morphological anomalies in Scaphirhynchus spp. of the Middle and Lower Mississippi River
Author(s) -
Murphy C. E.,
Hoover J. J.,
George S. G.,
Lewis B. R.,
Killgore K. J.
Publication year - 2007
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/j.1439-0426.2007.00882.x
Subject(s) - peduncle (anatomy) , sturgeon , biology , river mouth , river valley , zoology , fishery , anatomy , fish <actinopterygii> , geography , paleontology , archaeology , sediment
Summary Sturgeon specimens encountered in the wild that exhibit visible signs of gross physical trauma often look to the naked eye to be in otherwise good condition. Visible morphological anomalies were observed in 9.1% of 176 pallid ( Scaphirhynchus albus ) and 4.6% of 4904 shovelnose ( Scaphirhynchus platorynchus ) sturgeon specimens captured in the Middle (mouth of Missouri River to mouth of Ohio River) and Lower (below mouth of Ohio River) Mississippi River from 1997 to 2004. Frequencies among the types of anomalies differed between the lower and middle river reaches. In the lower river, deformities from foreign objects (typically rubber bands) comprised almost one‐third of anomalies observed and may have contributed to other types of anterior injury which, if combined, would comprise the majority of lower river anomalies. In the middle river, nearly half of the observed anomalies involved damage to the caudal peduncle, usually a missing tail. Power regressions from length–weight relationships were compared for anomalous and non‐anomalous specimens and demonstrated no significant disparity, verifying the resiliency of river sturgeons.