Testing a selective tidal‐stream transport model: Observations of female blue crab (Callinectes sapidus) vertical migration during the spawning season

Abstract

Female blue crabs, Callinectes sapidus, mate in estuaries and undergo a seaward spawning migration to release larvae. According to the prevailing model, females with mature embryos use nocturnal ebb-tide transport (ETT) to move seaward, release larvae, and then reverse to nocturnal flood-tide transport (FTT) to move back into the estuary. We tested this model by examining the vertical migratory behavior of ovigerous and post-larval release female crabs. Simultaneous physical-biological data were collected for 38 d during Aug 2002-Sep 2002 in Bogue Sound, North Carolina. Crab water-column positions were determined with miniature internally recording pressure sensors. Local current and water properties were measured, and crab vertical migration times relative to observed currents were used to determine ETT and FTT behavior. Surface censuses of free-swimming crabs on 19 nocturnal ebbs were used to complement the intensive studies of individual crabs. The study found that (1) the pressure sensors had a measurable but small effect on swimming, (2) females migrated during day and night ebb tides, (3) females used ETT throughout embryo development, (4) ETT corresponded to the rate of decrease in water level (hydrostatic pressure), (5) larvae were released at high tide or when water level was falling, often within several hours of sunrise, and (6) post-larval release females continued ETT and did not switch to FTT. Thus, the data did not support the prevailing ETT-FTT reversal model. Rather, females continue ETT into coastal areas, releasing subsequent clutches farther seaward, which increases the potential for successful larval transport to favorable offshore developmental areas.For many marine species, successful recruitment entails adult migration out of an estuary and subsequent larval transport into an estuary. While substantial literature is accumulating on the latter process (e.g., Weinstein 1988; Crowder and Werner 1999;Epifanio and Garvine 2001), 1 To whom correspondence should be addressed. Present address: Environmental Fluid Mechanics Laboratory, Stanford University, Stanford, California 94305-24-4020 (jhench@stanford.edu). AcknowledgmentsWe thank Pia Moisander and Josh Osterberg for valuable assistance in the field. Sean Powers and two anonymous reviewers provided helpful suggestions on the manuscript.

The missing link: tidal‐influenced activity a likely candidate to close the migration triangle in brown shrimp Crangon crangon (Crustacea, Decapoda)

“…In experiments with a light–dark cycle the observed behavior of the shrimps switched, after some time, to increased and sometimes continuous night activity. The general behavior of C. crangon in our experiments compared well with observations of other decapods such as Uca minax (López‐Duarte and Tankersley, ) and Callinectes sapidus (Hench et al ., ). Endogenous rhythms were also found for Farfantepenaeus duorarum and Litopenaeus setiferus (Ogburn et al ., ) and the memory time, meaning the length of the time that shrimps displayed an endogenous controlled tide‐related activity pattern, was comparable to that observed in our study.…”

“…Callinectes sapidus (Hench et al, 2004). Endogenous rhythms were also found for Farfantepenaeus duorarum and Litopenaeus setiferus (Ogburn et al, 2013) and the memory time, meaning the length of the time that shrimps displayed an endogenous controlled tiderelated activity pattern, was comparable to that observed in our study.…”

Grooming behaviors and gill fouling in the commercially important blue crab (Callinectes sapidus) and stone crab (Menippe mercenaria)

“…They often live in seagrass beds and swim in water columns and currents (Ward, 2012) that decrease the settling of sediment and debris. While blue crabs are active and are exposed to different environments during their migrations, their activity levels are highest at night and not during day/light hours when epibionts could grow and increase fouling levels; blue crabs are most active at nighttime (Hench et al, 2004). Along with not being constantly bathed in burrows of clay/silt sediment (burrowing is shallow and seasonal in blue crabs; Ward, 2012), blue crabs may not need to groom as often, even though they are highly active (Tab.…”

Spatial patterns in the ovigerous Callinectes sapidus spawning migration: results from a coupled behavioral-physical model

“…5 & 6). It is likely that tagging and/or tethering effects in the Hench et al (2004) study resulted in a decrease in the mean number of migratory episodes relative to natural levels. Despite this uncertainty, these data are the best estimates of the timing of migratory episodes available, and allowed us to capture migratory trajectories and temporal patterns in migratory episodes in a realistic manner.…”