Habitat Use and Population Dynamics of Blue Crabs,<i>Callinectes sapidus</i>, in a High-Salinity Embayment

Ramach, Sean; Darnell, M. Zachary; Avissar, Naomi; Rittschof, Daniel

doi:10.2983/035.028.0328

Cited by 23 publications

(21 citation statements)

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“…Ramach et al (2009) examined population dynamics in a high-salinity embayment and found that during peak spawning times ovigerous females comprised 23% of the total population. If nonovigerous, mature females are included, females comprised 76% of the adult crab population (Ramach et al 2009). In high-salinity dredge fisheries, such as the recently closed Virginia winter dredge fishery, the catch is more than 90% females (Burreson et al 2000).…”

Section: Restrictions On Harvesting Ovigerous Crabs Protect Onlysupporting

confidence: 67%

“…This percentage does not include crabs between clutches of eggs. Ramach et al (2009) examined population dynamics in a high-salinity embayment and found that during peak spawning times ovigerous females comprised 23% of the total population. If nonovigerous, mature females are included, females comprised 76% of the adult crab population (Ramach et al 2009).…”

Section: Restrictions On Harvesting Ovigerous Crabs Protect Onlymentioning

confidence: 99%

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Postcapture Survival and Future Reproductive Potential of Ovigerous Blue Crabs Callinectes sapidus Caught in the Central North Carolina Pot Fishery

Darnell

McDowell

et al. 2010

Trans Am Fish Soc

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Harvest restrictions by sex or reproductive status are used to protect many spawning stocks. In most U.S. states, fishery regulations for blue crabs Callinectes sapidus require release of ovigerous crabs. Ovigerous crabs caught in pots become stressed by capture and physically damage the egg mass and remove eggs. We conducted a survey to assess the extent of egg mass damage in pot‐caught crabs as well as crabs caught by hand and not subjected to pot stress. Egg mass damage was more prevalent in pot‐caught crabs (>45% during all months) than in crabs caught by hand (<6% during all months). We investigated the postcapture survival, reproductive output, and larval viability of crabs with varying amounts of egg mass damage by collecting ovigerous crabs from the pot fishery and confining them in the field for the duration of their lifetimes. Over 80% of the crabs survived to release the clutch present at capture, and crabs produced up to six clutches of eggs. Of 156 clutches produced in confinement, only 1 was damaged. Crabs confined individually and fed do not experience the stress that causes egg mass damage in pots. The lipid content of early‐stage eggs (77.0 ± 1.3% [mean ± SE]), larval carapace width (269.0 ± 3.34 μm), and larval survival time without food (3.0 ± 0.11 d) were similar for all clutches and levels of egg mass damage. Clutch volume decreased by approximately 20% with each subsequent clutch, and the percentage of embryos developing normally decreased from 97 ± 0.6% for clutch 1 to 79 ± 10.8% for clutch 5. Immediate release of ovigerous crabs could be a viable management strategy, but it would have severe economic consequences for fishermen in high‐salinity areas. Area closures, combined with subsidies for crabbers during critical times, may be the most viable management strategy until crab populations recover from current diminished levels.

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Section: Restrictions On Harvesting Ovigerous Crabs Protect Onlysupporting

confidence: 67%

Section: Restrictions On Harvesting Ovigerous Crabs Protect Onlymentioning

confidence: 99%

Postcapture Survival and Future Reproductive Potential of Ovigerous Blue Crabs Callinectes sapidus Caught in the Central North Carolina Pot Fishery

Darnell

McDowell

et al. 2010

Trans Am Fish Soc

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“…While confined in the minnow traps, crabs were unable to migrate as they would in the wild (Forward et al 2003), although we feel that this would have little, if any, effect on clutch production. Crabs were collected from and confined in high-salinity (~35) areas that are both mating habitat and spawning habitat for blue crabs (Ramach et al 2009). Any environmental changes experienced by crabs migrating seaward from the sites would be minimal.…”

Section: Discussionmentioning

confidence: 99%

“…Females were confined individually in plastic minnow traps (42 × 23 cm) buried halfway into the sediment on their long axis in the immediate subtidal at the Duke University Marine Lab. The collection site and the confinement site are typical of high-salinity spawning habitat, with salinities remaining relatively constant at 35 (Ramach et al 2009). When water temperatures were above 14.5°C, crabs were fed daily with seasonal fish (typically pinfish, spot, and croaker) and shrimp through the end of the trap that protruded into the water column.…”

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Lifetime reproductive potential of female blue crabs Callinectes sapidus in North Carolina, USA

Darnell¹,

Rittschof²,

Darnell³

et al. 2009

Mar. Ecol. Prog. Ser.

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We examined lifetime clutch production and size at maturity for blue crabs Callinectes sapidus Rathbun in North Carolina, USA. Female crabs were collected at terminal molt and confined individually in the field for the duration of their lifetime. Crabs were monitored weekly for the presence of eggs. Clutch quality and larval viability were assessed for each clutch. Crabs produced up to 7 clutches over 1 to 2 spawning seasons and survived up to 394 d after the terminal molt. Time to first clutch and time between clutches were positively correlated with carapace width and best described by degree-days, physiological time calculated as a thermal integral. Size at maturity was negatively correlated with water temperature on the day of the terminal molt. Egg lipid content (mean = 79.2% of dry mass), egg diameter (mean = 267.5 µm), larval carapace width (mean = 278.4 µm), and larval survival time without food (mean = 3.4 d) were similar for all clutches. The percentage of embryos developing normally decreased 40% from Clutch 1 to 4, and clutch volume decreased 50% from Clutch 1 to 5. Thus, most of a crab's reproductive output is from the first few clutches. Realistic estimates of fecundity and reproductive potential are essential for accurate spawning stock assessment and population modeling. KEY WORDS: Blue crab · Callinectes sapidus · Reproductive potential · Spawning biology · Fecundity · Multiple clutches · Degree-days Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 394: [153][154][155][156][157][158][159][160][161][162][163] 2009 serves to reduce the risk of predation and sperm competition (Jivoff 1997). Thus, the duration of the postcopulatory embrace depends on the presence of conspecific predators, sex ratio, and male size and density (Jivoff 1997). Approximately 12% of females mate with at least a second male (Jivoff 1997). Females mate only following the terminal molt (Van Engel 1958); thus, all clutches produced by a female must be fertilized by stored sperm. Sufficient sperm is stored to fertilize up to a dozen clutches of eggs . Wolcott et al. (2005) found that the number and viability of sperm transferred during mating are independent of male and female body size. Female crabs then forage, develop mature ovaries, extrude a first clutch, and undertake a seaward spawning migration (Van Engel 1958, Tankersley et al. 1998, Turner et al. 2003, Forward et al. 2005) using both ebb-tide transport and directed walking during flood tides (Forward et al. 2003. Spawning females produce multiple clutches, and migratory behavior continues between clutches, ensuring that spawning females are continually moving seaward throughout the spawning season , Forward et al. 2005.Studies of crab and lobster reproductive potential have traditionally examined fecundity for only a single clutch (e.g. Pillay & Nair 1971, Hines 1982, Campbell & Robinson 1983, Jones & Simons 1983, Dugan et al. 1994, Medina Mantelatto & Fransozo 1997, presumably due to the difficulty of obser...

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“…The life of C. sapidus occurs in a variety of habitats. It includes population stratification, migratory activities mainly related to gender, ontogenetic, reproductive, and trophic aspects (Mcclintock et al 1993, Ramach et al 2009). Inside the estuary and regions of low salinity, there is the predominance of juveniles of both sexes.…”

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confidence: 99%

Fecundity, reproductive seasonality and maturation size of <i>Callinectes sapidus</i> females (Decapoda: Portunidae) in the Southeast coast of Brazil

Rodrigues

Musiello-Fernandes

Moura

et al. 2013

RBT

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C. sapidus fisheries has a significant influence on the economy of some countries in North America and has a relative extensive literature in these regions. However, only few papers discuss the ecology of C. sapidus in the South Atlantic, despite its economic importance in that region. We studied the fecundity, reproductive seasonality and maturation size of C. sapidus females captured in the Southeast coast of Brazil from January to December 2002. Females were separated, weighted (Wt), and cephalothorax width (CW) was measured. Furthermore, the eggs-masses were classified according to embryonic development, separated, weighted (We) and fixed. Eggs were also separated and counted, resulting in the average number of eggs per individual (Ne). A total sample of 307 females was collected: 78 young, 130 adults and 99 ovigerous. Ovigerous females showed CW between 7.49 and 15.89cm with average of 12.21cm and were distributed throughout the sample period, with highest incidence between December and March. The onset of morphological maturity (L 50 ) occurred at CW=10.33cm, and the size in which all were mature (L 100 ) was CW=11.20cm. Individual fecundity ranged from 689 356 to 3 438 122 with an average of 2 006 974. The CW showed a positive growth trend with Ne and We. We concluded that in order to ensure the resource sustainability, it is necessary to prohibit captures of C. sapidus in these regions, especially during summer. Additionally, our studies suggest that the minimum capture size should be 11cm of carapace width. Rev. Biol. Trop. 61 (2): 595-602. Epub 2013 June 01.

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Habitat Use and Population Dynamics of Blue Crabs,Callinectes sapidus, in a High-Salinity Embayment

Cited by 23 publications

References 10 publications

Postcapture Survival and Future Reproductive Potential of Ovigerous Blue Crabs Callinectes sapidus Caught in the Central North Carolina Pot Fishery

Postcapture Survival and Future Reproductive Potential of Ovigerous Blue Crabs Callinectes sapidus Caught in the Central North Carolina Pot Fishery

Lifetime reproductive potential of female blue crabs Callinectes sapidus in North Carolina, USA

Fecundity, reproductive seasonality and maturation size of <i>Callinectes sapidus</i> females (Decapoda: Portunidae) in the Southeast coast of Brazil

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