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.

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].

Changes in the Composition of Snow Crab (Chionoecetes opilio) Participating in the Annual Breeding Migration in Bonne Bay, Newfoundland

1990 ◽  
Vol 47 (11) ◽  
pp. 2242-2249 ◽  
Author(s):  
G. P. Ennis ◽  
R. G. Hooper ◽  
D. M. Taylor
Keyword(s):  
Reproductive Potential ◽  
Snow Crab ◽  
Rapid Decline ◽  
Chionoecetes Opilio ◽  
Scuba Divers ◽  
Crab Population ◽  
High Incidence ◽  
Breeding Migration ◽  
High Level ◽  
Snow Crabs

Sexually-paired snow crabs (Chionoecetes opilio) participating in an annual spring breeding migration to shallow water in Bonne Bay, Newfoundland were collected by SCUBA divers from 1984 to 1989. In 1984 the breeding pairs were composed mainly of relatively large, old-shell animals of both sexes, but by 1988 much smaller animals, most of which were new-shell, dominated the migration. Evidence from research fishing indicates that these changes are related to a rapid decline in what was characteristically a virgin population in 1984 and a coinciding strong pulse of recruitment into the breeding component of the population. A very high incidence of small, subcommercial males participating in the 1988 and 1989 breeding migrations demonstrates a capacity for maintaining a high level of reproductive potential in a snow crab population despite high exploitation rates on larger animals in the male-only fishery for this species. The strong recruitment pulse which occurred in Bonne Bay as the virgin population declined after 1984 also indicates a capacity for enhanced annual production within a snow crab population when exploitation rates are high.

Catch forecasting and relationship between water temperature and catch fluctuations in snow crab Chionoecetes opilio in the western Sea of Japan

2007 ◽  
Vol 73 (4) ◽  
pp. 837-844
Author(s):  
Daisuke YAMANAKA ◽  
Kazumi SAKURAMOTO ◽  
Naoki SUZUKI ◽  
Tohru NAGASAWA
Keyword(s):  
Water Temperature ◽  
Sea Of Japan ◽  
Snow Crab ◽  
Chionoecetes Opilio

SERUM PROTEIN CONCENTRATION AND SOMATIC INDEX IN RELATION TO MORPHOMETRIC MATURITY FOR MALE SNOW CRAB, CHIONOECETES OPILIO (O. FABRICIUS, 1788), IN THE BAIE DES CHALEURS, CANADA (DECAPODA, BRACHYURA)

Crustaceana ◽  
1999 ◽  
Vol 72 (5) ◽  
pp. 497-506 ◽  
Author(s):  
Michel Comeau ◽  
Marc Lanteigne ◽  
Roland Cormier
Keyword(s):  
Serum Protein ◽  
Protein Concentration ◽  
Mature Male ◽  
Snow Crab ◽  
Juvenile Male ◽  
Chionoecetes Opilio ◽  
Wet Weight ◽  
Snow Crabs ◽  
Somatic Index ◽  
Serum Protein Concentration

AbstractThe serum protein concentrations of juvenile and mature male snow crabs, Chionoecetes opilio, were measured using a refractometer. The somatic indices of juvenile and mature male snow crab were calculated using the weight of the dry flesh of the chelae versus its wet weight. Results indicate that juvenile male snow crab have significantly higher serum protein concentrations and significantly lower somatic indices than their mature counterparts. These observations are attributed to basic physiological differences that could be explained by a terminal moult. Les concentrations en proteines seriques de males juveniles et a maturite du crabe des neiges Chionoecetes opilio ont ete mesurees au moyen d'un refractometre. Les indices somatiques de ces individus ont ete calcules en utilisant le rapport entre le poids sec et le poids humide de la chair. Les resultats indiquent que les individus males juveniles ont des concentrations en proteines seriques significativement plus elevees et des indices somatiques significativement plus bas que les individus males matures. Ces observations sont attribuees a des differences physiologiques de base qui peuvent etre expliquees par une mue terminale.

scholarly journals The contribution of fecundity and embryo quality to reproductive potential of eastern Bering Sea snow crab (Chionoecetes opilio)

2016 ◽  
Vol 73 (12) ◽  
pp. 1800-1814 ◽  
Author(s):  
Joel B. Webb ◽  
Laura M. Slater ◽  
Ginny L. Eckert ◽  
Gordon H. Kruse
Keyword(s):  
Bering Sea ◽  
Embryo Quality ◽  
Stock Assessment ◽  
Reproductive Potential ◽  
Large Male ◽  
Reference Points ◽  
Snow Crab ◽  
Eastern Canada ◽  
Chionoecetes Opilio ◽  
Eastern Bering Sea

Development of refined indices of female reproductive potential is needed for estimation of alternative biological reference points for the eastern Bering Sea (EBS) snow crab (Chionoecetes opilio) fishery, which is managed with large male-only harvest regulations. Females were collected from 2007 to 2009 to investigate seasonal and interannual variation in fecundity with maternal size, shell condition (a proxy for age after maturity), and recent mating and again in 2010 to examine biochemical measures (carbon, hydrogen, and nitrogen) of embryo quality. Mean model-adjusted fecundity was highest for primiparous and young multiparous females and declined with advancing shell condition, presumably from senescence. This pattern was also found for clutch fullness indices evaluated from 20 years of stock assessment survey data. Indicators of low female sperm reserves were associated with decreased (∼10%) fecundity for multiparous females. Seasonal comparison of size–fecundity relationships suggested that embryo loss during brooding was minimal, and embryo quality analyses suggested that strong variation with maternal characteristics was unlikely. Finally, fecundity-at-size of EBS females may be lower than that of conspecifics in Japan and eastern Canada.

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

Cuticular repair in the mature male snow crab, Chionoecetes opilio (Majidae; Crustacea): relation to ecdysteroids

1992 ◽  
Vol 70 (2) ◽  
pp. 314-319 ◽  
Author(s):  
K. Halcrow ◽  
C. G. H. Steel
Keyword(s):  
Light Microscopy ◽  
Dorsal Surface ◽  
Mature Male ◽  
Snow Crab ◽  
Chionoecetes Opilio ◽  
Snow Crabs

Morphometrically mature male snow crabs, Chionoecetes opilio, are not known to molt; they are believed to lack functional Y-organs and hence molting hormones. Small regions of the dorsal surface of crabs were damaged and the ensuing repair of the cuticle was followed by light microscopy at intervals of up to 60 days. Events within the limb base after forced autotomy of a single pereiopod were also investigated and compared with cuticle deposition in limb bases of pereiopods autotomized before the crabs' arrival in the laboratory. Circulating ecdysteroids were assayed by radioimmunoassay at intervals throughout the experiments. New cuticle was deposited in response to all types of injury and in a manner similar to that described previously. New cuticle was deposited across the breakage plane of autotomized limb bases; a complete and substantial layer was present in many of the bases of previously autotomized legs. Neither basal growth nor premolt growth was detected in the base of any autotomized limb. Ecdysteroids were detectable in the hemolymph of most crabs but at low titers, ranging from 6.0 to 11.6 ng/mL.

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.

Reproductive products in the adult snow crab (Chionoecetes opilio). II. Multiple types of sperm cells and of spermatophores in the spermathecae of mated females

1999 ◽  
Vol 77 (3) ◽  
pp. 451-462 ◽  
Author(s):  
Guy Sainte-Marie ◽  
Bernard Sainte-Marie
Keyword(s):  
Reproductive Tract ◽  
Periodic Acid ◽  
Cell Types ◽  
Female Reproductive Tract ◽  
Snow Crab ◽  
Chionoecetes Opilio ◽  
Cellular Debris ◽  
Snow Crabs ◽  
Amorphous Matter

Contents of the spermathecae of mated adult snow crabs (Chionoecetes opilio) were examined by light microscopy. The contents could consist of water and three basic types of amorphous matter and of spermatophores. Water was present in the form of large patches or smaller spheres. Of the two major types of amorphous matter, one reacted positively and one negatively to periodic acid - Schiff's reagent (PAS), and one was only, and one predominantly, of male origin. The minor type of amorphous matter was orange and of female origin and could include dark cellular debris. Spermatophores enclosed either immature spermatids, mature spermatids, hitherto unreported spermatozoa, or cell forms intermediate between these three types. Peripheral mature spermatids and spermatozoa had a polarized orientation and were attached to the spermatophore wall. Overall, amorphous matter and spermatophores were topographically segregated by type within a spermatheca, and spermatophores enclosing immature spermatids occurred mostly in PAS-negative amorphous matter. Spermatid differentiation can unfold in the female reproductive tract as well as in the vas deferens, while the transformation of spermatids into spermatozoa was observed only in the female. The diversity of sperm cell types and the ordered placement of semen constituents within the spermatheca suggest that sperm are partitioned for short- or long-term use.

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