Description of Laboratory-Reared Larvae of Paralithodes platypus (Decapoda, Anomura, Lithodidae)

1968 ◽  
Vol 25 (3) ◽  
pp. 439-455 ◽  
Author(s):  
Ethelwyn G. Hoffman
Keyword(s):  
North Pacific ◽  
Dorsal Surface ◽  
The Other ◽  
Frontal Area ◽  
King Crab ◽  
Larval Stages ◽  
Blue King Crab ◽  
Paralithodes Platypus ◽  
Pacific Species ◽  
Branchial Region

Larvae of the blue king crab, Paralithodes platypus (Brandt), were hatched and reared in the laboratory. All larval stages obtained developed in a manner similar to the development reported for other lithodid anomurans. In culture, P. platypus had four zoeal stages and a single glaucothoeal stage. The feature which distinguishes all zoeal stages of this species from zoeae of the other two North Pacific species of Paralithodes — P. camtschatica and P. brevipes — is the presence of 9 + 9 telson processes (including a hair-like second process) rather than 8 + 8 telson processes. Glaucothoes of P. platypus have one more pair of spines in the branchial region of the carapace than do those of P. camtschatica. Glaucothoes of P. platypus have 15 pairs of spines on the dorsal surface of the carapace, not including the spines of the frontal area (rostral complex) or the suborbital spines, whereas glaucothoes of P. camtschatica have 14 pairs of spines, and those of P. brevipes have 13 pairs.

Biennial Reproductive Cycle of Blue King Crab, Paralithodes platypus, at the Pribilof Island, Alaska and Comparison to a Congener, P. camtschatica

1989 ◽  
Vol 46 (6) ◽  
pp. 932-940 ◽  
Author(s):  
Gregory C. Jensen ◽  
David A. Armstrong
Keyword(s):  
Carapace Length ◽  
Reproductive Output ◽  
Size Range ◽  
Egg Mass ◽  
King Crab ◽  
Pribilof Island ◽  
Blue King Crab ◽  
Paralithodes Platypus ◽  
One Year ◽  
Reproductive Events

Pribilof Island blue king crab (BKC; Paralithodes platypus) were sampled by beam trawl in May and August of 1983 and April 1984 to determine timing of reproductive events. Biennial reproduction was found to be the result of slow ovarian growth in large, muciparous females, while smaller primiparous females are often able to spawn in two consecutive years. Mating and egg extrusion occur in late March to early May and eggs hatch in mid-April of the following year, consequently, the embryonic period and rate of development is approximately 12 mo, similar to that of its congener the red king crab (RKC; P. camtschatica). Comparison of the reproductive output of the two species revealed that despite the 2 yr ovarian cycle, BKC only produce 20–30% more dry egg mass at any carapace length than do RKC, a substantially smaller difference than previously calculated. One year after molt, females of both species are not significantly different in dry body weight over a size range of 100–140 mm carapace length, but RKC have produced about three times more dry ovarian weight than BKC of comparable size, suggesting that biennial reproduction in BKC may be the result of energetic limitations.

scholarly journals Survival, growth, and morphology of blue king crabs: effect of ocean acidification decreases with exposure time

2016 ◽  
Vol 74 (4) ◽  
pp. 1033-1041 ◽  
Author(s):  
William Christopher Long ◽  
Scott B. Van Sant ◽  
Katherine M. Swiney ◽  
Robert J. Foy
Keyword(s):  
Mortality Rate ◽  
Ocean Acidification ◽  
Morphological Changes ◽  
Phenotypic Variability ◽  
Minor Effect ◽  
King Crab ◽  
Growth And Survival ◽  
Blue King Crab ◽  
Paralithodes Platypus ◽  
A Minor

Ocean acidification is an altering marine carbonate chemistry resulting in potential effects to marine life. In this study, we determine the effects of decreased pH on the morphology, growth, and survival of juvenile blue king crab, Paralithodes platypus. Crabs were reared at three pH levels: ambient (control, pH ∼8.1), pH 7.8, and pH 7.5, for 1 year and monitored for morphological changes, survival, and growth. Exposure to seawater at pH 7.8 had no effect on morphology or mortality and had only a minor effect on growth compared with the ambient treatment. However, exposure to seawater at pH 7.5 substantially increased mortality and decreased growth compared with the ambient treatment. The best fit model of mortality rate at pH 7.5 showed an initially high mortality rate, which dropped to become comparable to the mortality rate in the other treatments. This suggests phenotypic variability or plasticity in juveniles and may indicate acclimation by blue king crab to ocean acidification. As such, blue king crab may have scope for evolutionary adaptation in response to gradually changing pH levels. However, effects on other life-history stages, sub-lethal effects, carryover or transgenerational effects, and interactions with other stressors, such as increased temperature, still need to be investigated.

Sign in / Sign up

Export Citation Format

Share Document