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Gonadal development and sex‐specific demographics of the shovelnose sturgeon in the Middle Mississippi River
Author(s) -
Colombo R. E.,
Garvey J. E.,
Wills P. S.
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.1439-0426.2007.00885.x
Subject(s) - biology , sturgeon , fecundity , fish measurement , lake sturgeon , sex ratio , sexual maturity , demographics , zoology , development of the gonads , fishery , fish <actinopterygii> , demography , ecology , acipenser , population , sociology
Summary Harvest of the shovelnose sturgeon, Scaphirhynchus platorynchus for caviar has increased. To determine whether populations can withstand increased harvest, detailed information regarding sexual demographics is needed. We describe gender and reproductive development of 306 shovelnose sturgeon from the Middle Mississippi River (River km 0–322) during September 2001 through December 2003. Using dissection and histology, we identified three of the four gonadal stages described previously for male lake sturgeon and all seven stages for females. Males reached maturity at a smaller size than did females. Gonads can be rapidly inspected for sex and stage of development for the shovelnose sturgeon. The sex ratio was not different from 1 : 1. Seven intersexual fish occurred. Female fecundity was positively related to body weight (number of eggs = 30.24 × body weight − 8392; P = 0.013; r 2 = 0.45) and weakly related to fork length (number of eggs = 146.37 × fork length − 66 176, P = 0.053, r 2 = 0.23).