Use of reflex indicators for measuring vitality and mortality of the snow crab (Chionoecetes opilio ) in captivity

2019 ◽  
Vol 50 (4) ◽  
pp. 1321-1328 ◽  
Author(s):  
Philip James ◽  
David Izquierdo-Gómez ◽  
Sten I. Siikavuopio
Keyword(s):  
Snow Crab ◽  
Chionoecetes Opilio ◽  
In Captivity

Functional Maturity in Small Male Snow Crabs (Chionoecetes opilio)

1988 ◽  
Vol 45 (12) ◽  
pp. 2106-2109 ◽  
Author(s):  
G. P. Ennis ◽  
R. G. Hooper ◽  
D. M. Taylor
Keyword(s):  
Rapid Development ◽  
Carapace Width ◽  
Reproductive Potential ◽  
Snow Crab ◽  
Small Male ◽  
Chionoecetes Opilio ◽  
In Captivity ◽  
Breeding Migration ◽  
High Level ◽  
Snow Crabs

The mean size of male snow crabs (Chionoecetes opilio) in sexual pairs during the annual spring breeding migration to shallow water in Bonne Bay, Newfoundland, decreased from 118.6 mm carapace width (CW) in 1983 to 100.3 mm in 1987. This decrease is due to an increase in males <95 mm CW participating from 1.5% in 1983 to 32.3% in 1987. This change appears to have resulted from a reduced abundance of commercial size [Formula: see text] males due to a rapid development of an illegal fishery on this previously unfished population and, as a consequence, less competition between males for possession of females. The percentages of spermathecae containing new spermatophores for females paired with males <95 mm CW (67%) and those with males [Formula: see text] (79%) were not significantly different. We assumed that each female with new spermatophores had recently mated with the male with which it was paired. Observations on selected pairs in captivity showed that males <95 mm CW are capable of mating with both primiparous and muitiparous females. Our results indicate that small mature males can replace large males in breeding activity in a snow crab population. We conclude that in the male-only snow crab fishery in Atlantic Canada with a minimum legal size of 95 mm CW, population reproductive potential is maintained at a high level despite high exploitation rates on males [Formula: see text].

Embryo development and reproductive cycle in the snow crab, Chionoecetes opilio (Crustacea: Majidae), in the southern Gulf of St. Lawrence, Canada

1998 ◽  
Vol 76 (11) ◽  
pp. 2040-2048 ◽  
Author(s):  
Mikio Moriyasu ◽  
Carole Lanteigne
Keyword(s):  
Water Temperature ◽  
Embryo Development ◽  
Reproductive Potential ◽  
Snow Crab ◽  
Intermediate Water ◽  
Pigment Formation ◽  
Chionoecetes Opilio ◽  
In Captivity ◽  
Higher Temperature ◽  
Snow Crabs

Embryonic stages and egg-incubation durations were compared between female snow crabs, Chionoecetes opilio, in captivity and from the wild. In the southern Gulf of St. Lawrence the incubation time is 24-27 months. There are two prolonged periods of embryo development: (1) stages 3 and 4 (cleavage and blastula, gastrula) last for at least 6 months between May and January following egg extrusion, and (2) stages 11 and 12 (eye-pigment formation, chromatophore formation) last for 3-4 months between October and January of the following year. Water temperature plays an important role in determining the egg-development rate. Embryo development takes 12-13.5 months (365-410 days) when females are kept at a higher temperature (1.8-3.8°C) than that of the normal habitat (-1 to +1°C). Ovigerous females usually inhabit depths of 40-100 m, which is the cold intermediate water in the southern Gulf of St. Lawrence (year-round temperature and salinity -1 to +1°C and 32-33‰, respectively). However, ovigerous females are also observed at depths of 100-300 m in the Laurentian Channel, where the year-round water temperature is 3-5°C. For ovigerous females that do not migrate to the deeper, warmer waters, the duration of embryo development is 2 years, whereas females that inhabit deeper waters develop their embryos over a 1-year cycle. The reproductive potential and abundance of females with 1- and 2-year embryo-development cycles in the southern Gulf of St. Lawrence are unknown.

A Critical Look at the Idea of Terminal Molt in Male Snow Crab (Chionoecetes opilio)

1991 ◽  
Vol 48 (11) ◽  
pp. 2266-2275 ◽  
Author(s):  
Earl G. Dawe ◽  
David M. Taylor ◽  
John M. Hoenig ◽  
William G. Warren ◽  
Gerald P. Ennis ◽  
...  
Keyword(s):  
Limb Regeneration ◽  
Field Studies ◽  
Snow Crab ◽  
Mouth Part ◽  
Laboratory Studies ◽  
Limb Buds ◽  
Chionoecetes Opilio ◽  
In Captivity

Whether or not male snow crab (Chionoecetes opilio) undergo a terminal molt when they develop large chelae is reviewed. Evidence supporting terminal molt includes laboratory studies in which large-clawed animals failed to molt and field studies which failed to find large-clawed males with mouth parts indicating imminent molting. Both studies were poorly documented. The field studies were largely conducted during inappropriate seasons and molt status based on a questionable mouth part stage. There is also an unsubstantiated claim that large-clawed animals fail to form limb buds for limb regeneration during the next molt and an inconclusive study of the degeneration of the Y-organ. We present new data against terminal molt including capture of large-clawed males with internal carapaces indicating impending molts, capture of two large-clawed animals with mouth parts indicating active premolting, recovery of two tagged large-clawed animals which molted while at liberty, and that the largest small-clawed animals usually are not large enough to account (through growth in a single molt) for the largest of the large-clawed animals. Also, one large-clawed male reportedly molted in captivity. We conclude that the existence of a terminal molt in male snow crab is not proven.

scholarly journals Size-at-maturity shift in a male-only fishery: factors affecting molt-type outcomes in Newfoundland and Labrador snow crab (Chionoecetes opilio)

2020 ◽  
Author(s):  
Darrell R J Mullowney ◽  
Krista D Baker
Keyword(s):  
Population Density ◽  
Newfoundland And Labrador ◽  
Cold Water ◽  
Large Male ◽  
Snow Crab ◽  
Size At Maturity ◽  
Chionoecetes Opilio ◽  
Factors Affecting ◽  
Male Density ◽  
Process Factors

Abstract A sex-asymmetric downward shift in size-at-terminal-molt has recently occurred in males in some portions of the Newfoundland and Labrador (NL) snow crab stock range, a first known occurrence for such processes in snow crab (Chionoecetes opilio) stocks. This study examines plausible factors promoting the shift in size-at-terminal-molt [synonymous with size-at-maturity (SaM)] including individual size, temperature, population density, and sex ratio. Analyses highlight expanse of cold water and large male density as being significant predictors of molt-type outcomes. A confluence of cold conditions and low density of large males promoted the SaM shift. In turn, the low male density was associated with recently elevated fishery exploitation rates under quota-controlled management. It remains unknown the extent to which the reduction in terminal size reflects a phenotypic vs. genotypic process. Factors affecting skip-molting in male snow crab are investigated, and we find that skip-molting occurs most frequently under extreme cold and high population density conditions. Potential complications arising from altered growth dynamics are discussed. Overall, the results advance knowledge on intraspecific competition processes within snow crab populations and inform fisheries management systems that male-only harvest strategies do not provide full protection from biological harm to aquatic resources through fishing.

scholarly journals Panmixia in Alaskan populations of the snow crab Chionoecetes opilio (Malacostraca: Decapoda) in the Bering, Chukchi, and Beaufort Seas

2014 ◽  
Vol 34 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Gregory T. Albrecht ◽  
Kris J. Hundertmark ◽  
Alexandra E. Valentin ◽  
Sarah M. Hardy
Keyword(s):  
Snow Crab ◽  
Chionoecetes Opilio

SHELL STRENGTH AND CARAPACE SIZE IN NON-ADULT AND ADULT MALE SNOW CRAB (CHIONOECETES OPILIO)

2000 ◽  
Vol 20 (2) ◽  
pp. 399-406 ◽  
Author(s):  
J-D. Dutil ◽  
C. Rollet ◽  
R. Bouchard ◽  
W. T. Claxton
Keyword(s):  
Adult Male ◽  
Snow Crab ◽  
Chionoecetes Opilio

Tissue specificity and ontogeny of lactate dehydrogenase in snow crab, Chionoecetes opilio (Brachyura, Majidae)

1994 ◽  
Vol 108 (3) ◽  
pp. 385-395 ◽  
Author(s):  
Annie Angers ◽  
François Pothier ◽  
Jean-Marie Sévigny ◽  
Bernard Sainte-Marie
Keyword(s):  
Lactate Dehydrogenase ◽  
Tissue Specificity ◽  
Snow Crab ◽  
Chionoecetes Opilio

Regime shifts and recruitment dynamics of snow crab,Chionoecetes opilio,in the eastern Bering Sea

2013 ◽  
Vol 22 (5) ◽  
pp. 345-354 ◽  
Author(s):  
Cody Szuwalski ◽  
André E. Punt
Keyword(s):  
Bering Sea ◽  
Regime Shifts ◽  
Snow Crab ◽  
Chionoecetes Opilio ◽  
Eastern Bering Sea

scholarly journals Effect of Morphometric Maturity and Size on Enzyme Activities and Nucleic Acid Ratios in the Snow Crab Chionoecetes Opilio

1998 ◽  
Vol 18 (2) ◽  
pp. 232-242 ◽  
Author(s):  
Elise Mayrand ◽  
Helga Guderley ◽  
Jean-Denis Dutil
Keyword(s):  
Nucleic Acid ◽  
Enzyme Activities ◽  
Snow Crab ◽  
Chionoecetes Opilio
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