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.

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.

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].

Hemolymph Ecdysone Concentration as a Function of Sexual Maturity in the Male Snow Crab (Chionoecetes opilio)

1992 ◽  
Vol 49 (8) ◽  
pp. 1619-1623 ◽  
Author(s):  
Roland J. Cormier ◽  
Alan R. Fraser ◽  
Richard F. J. Bailey ◽  
Nicole Raymond
Keyword(s):  
Sexual Maturity ◽  
Carapace Width ◽  
Dry Weight ◽  
Mature Male ◽  
Snow Crab ◽  
Allometric Relationship ◽  
Biochemical Basis ◽  
Chionoecetes Opilio ◽  
Relationship Of ◽  
Juvenile Crab

Ecdysone concentrations in the hemolymph of juvenile and morphometrically mature male snow crab (Chionoecetes opilio) were determined by radioimmunoassay. A logarithmic transformation of the allometric relationship of the dry weight of the chelae versus the carapace width was used to identify morphometric maturity. Results indicate that concentrations of ecdysone found in the hemolymph of juvenile crab are higher than those found in morphometrically mature crab, thus providing a biochemical basis for the observation that the onset of sexual maturity seems to coincide with a terminal molt.

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.

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.

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.

scholarly journals Seasonal migrations of morphometrically mature male snow crab (Chionoecetes opilio) in the eastern Bering Sea in relation to mating dynamics

2015 ◽  
Vol 113 (3) ◽  
pp. 313-326 ◽  
Author(s):  
Daniel G. Nichol ◽  
David A. Somerton
Keyword(s):  
Bering Sea ◽  
Mature Male ◽  
Snow Crab ◽  
Chionoecetes Opilio ◽  
Eastern Bering Sea ◽  
Seasonal Migrations

Reproductive products in the adult snow crab (Chionoecetes opilio). I. Observations on spermiogenesis and spermatophore formation in the vas deferens

1999 ◽  
Vol 77 (3) ◽  
pp. 440-450 ◽  
Author(s):  
Guy Sainte-Marie ◽  
Bernard Sainte-Marie
Keyword(s):  
Light Microscopy ◽  
Reproductive Tract ◽  
Vas Deferens ◽  
Periodic Acid ◽  
Snow Crab ◽  
Sperm Cells ◽  
Periodic Acid Schiff ◽  
Male Reproductive Tract ◽  
Chionoecetes Opilio ◽  
Amorphous Matter

Some of the events unfolding in the vas deferens of the adult snow crab (Chionoecetes opilio) were examined by means of light microscopy. Sperm cells entered the vas deferens as precursors of immature spermatids and developed into immature or mature spermatids within it. However, spermatozoa were not observed in the male reproductive tract. Two types of amorphous matter were added successively to sperm cells in the vas deferens. The first type was periodic acid - Schiff (PAS)-positive and apparently induced spermiogenesis when present in a sufficiently large amount. However, a smaller amount of this amorphous matter was sufficient to form the basal pellicle of spermatophores. The second type was PAS-negative and thickened the wall of spermatophores. Immature and mature spermatids were usually enclosed within distinct spermatophores. Enclosed mature spermatids were connected together by bridges formed by Feulgen-positive spikes coated and extended by PAS-positive amorphous matter. Once broken, the bridges appeared as arms that radiated from a spermatid. Peripheral mature spermatids were furthermore linked to the spermatophore wall by threads of PAS-positive amorphous matter. The bridges and threads may form a pathway for the diffusion of extraneous substances through the spermatophore wall to the innermost cells.

Morphological, Electrophoretic and Fecundity Characteristics of Atlantic Snow Crab, Chionoecetes opilio, and Implications for Fisheries Management

1985 ◽  
Vol 42 (3) ◽  
pp. 474-482 ◽  
Author(s):  
K. Davidson ◽  
J. C. Roff ◽  
R. W. Elner
Keyword(s):  
Management Tool ◽  
Snow Crab ◽  
Western Cape ◽  
Genetic Stock ◽  
Chionoecetes Opilio ◽  
Cape Breton Island ◽  
Cape Breton ◽  
Genetic Stocks ◽  
Electrophoretic Data ◽  
Snow Crabs

For adult snow crabs (Chionoecetes opilio), from the western Gulf of St. Lawrence, eastern and western Cape Breton Island, and eastern Newfoundland, we compared morphometric, meristic, electrophoretic, and fecundity characteristics. Our morphometric, meristic, and fecundity data indicated that snow crabs from the four areas are morphologically and biologically distinct; therefore, they represent four "phenotypic" or "biological" stocks. We propose that the differences in morphology are due largely to environmental effects on growth during juvenile stages. The electrophoretic data indicate that Newfoundland and western Gulf of St. Lawrence snow crabs differ genetically from each other and from the Cape Breton Island snow crabs; therefore, they represent two different "genetic" stocks. Eastern and western Cape Breton Island snow crabs did not exhibit electrophoretic differences and, thus, they represent a single genetic stock. Genetic exchange between Atlantic Canadian snow crab populations appears possible through larval dispersal. There is a widely different degree of resilience to exploitation and response to the same management strategy between eastern and western Cape Breton Island snow crab populations; hence, a phenotypically and/or genotypically defined stock is not necessarily a useful management tool. Stocks may be subdivided into more meaningful management units that reflect intra-stock factors such as growth and recruitment patterns.

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