Sex Ratios and Average Sperm per Female Blue CrabCallinectes sapidusin Six Tributaries of Chesapeake Bay

Abstract

Sperm limitation has been a concern for several crustacean species around the world. It may be of particular concern for blue crabs Callinectes sapidus in Chesapeake Bay due to the species’ reproductive biology and the sex‐specific fishery regulations in place. Our objectives were to characterize the differences in sperm counts in mated females from six tributaries of the Chesapeake Bay and to determine whether sperm quantity was affected by the ratio of males to females in each system. Mature females were sampled 1–4 times in each tributary on a biweekly schedule from September to November 2011. We quantified sperm storage for each crab by microscopic examination and compared the sperm counts of females among river systems with the adult male : female sex ratios using ANOVA and linear regression. Total sperm quantity per female varied 16‐fold (0.9–13.0 × 108) among tributaries. The sex ratio was also variable among tributaries. Total sperm quantity per female was not significantly related to sex ratio, tributary, or month but was negatively related to the development stage of the spermathecae. Estimated sperm : egg ratios varied from 153:1 to 2:1 but were always higher than 1:1. Our results suggest that sperm quantities are not affected by male : female sex ratios and that sperm limitation caused by low sex ratios is likely not a concern in tributaries similar to those in our study. Received April 3, 2015; accepted June 24, 2016

Ocean acidification does not overlook sex: Review of understudied effects and implications of low pH on marine invertebrate sexual reproduction

“…One study in copepods found that OA reduced the number of brooding females (Lee et al, 2019). Several crustacean studies, however, showed that fecundity or hatch rate were unaffected by OA Mayor et al, 2007;Egilsdottir et al, 2009;Zhang et al, 2011;Weydmann et al, 2012;McConville et al, 2013;Vehmaa et al, 2013;Cripps et al, 2014;Cao et al, 2015;Isari et al, 2015;Almeń et al, 2016;Rains et al, 2016;Zervoudaki et al, 2017;Thor et al, 2018;Langer et al, 2019). One study found that OA can increase fecundity, and another found that low pH increased reproductive output, but at the cost of body size and shell integrity (Fitzer et al, 2012b;Engström-Öst et al, 2014).…”

Morphometric Relationships of the Global Invader Callinectes sapidus Rathbun, 1896 (Decapoda, Brachyura, Portunidae) from Papapouli Lagoon, NW Aegean Sea, Greece. with Notes on Its Ecological Preferences

“…Relevant studies regard the species' life history and growth [1,3,15], diseases [16] and foraging behaviour [17,18]. There have also been studies related to the reproductive biology [19], population structure [20] and fisheries [6,21].…”

Evidence for Sperm Limitation in the Louisiana Blue Crab Spawning Stock

“…Previous work has found evidence for sperm limitation in a number of regions where blue crabs are actively harvested, including North Carolina (Wolcott et al 2005), the Atlantic coast of Florida (Hines et al 2003), and Chesapeake Bay (Kendall and Wolcott 1999; Kendall et al 2001, 2002; Hines et al 2003; Carver et al 2005; Ogburn et al 2014, 2019; Wells et al 2017), although Rains et al (2016) did not find evidence of sperm limitation in Chesapeake Bay. Despite the large and active blue crab fishery in the Gulf of Mexico (>19,000 metric tons in 2020; NMFS 2021), no data exist on sperm stores of female blue crabs in this region.…”