Upper thermal tolerance in red and blue king crab: sublethal and lethal effects

AbstractHow ectothermic animals will cope with global warming is a critical determinant of the ecological impacts of climate change. There has been extensive study of upper thermal tolerance limits among fish species but how intraspecific variation in tolerance may be affected by habitat characteristics and evolutionary history has not been considered. Intraspecific variation is a primary determinant of species vulnerability to climate change, with implications for global patterns of impacts of ongoing warming. Using published critical thermal maximum (CTmax) data on 203 fish species, we found that intraspecific variation in upper thermal tolerance varies according to a species’ latitude and evolutionary history. Overall, tropical species show a lower intraspecific variation in thermal tolerance than temperate species. Notably, freshwater tropical species have a lower variation in tolerance than freshwater temperate species, which implies increased vulnerability to impacts of thermal stress. The extent of variation in CTmax among fish species has a strong phylogenetic signal, which may indicate a constraint on evolvability to rising temperatures in tropical fishes. That is, in addition to living closer to their upper thermal limits, tropical species may have higher sensitivity and lower adaptability to global warming compared to temperate counterparts. This is evidence that freshwater tropical fish communities, worldwide, are especially vulnerable to ongoing climate change.

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Upper thermal tolerance of larval Arctic lamprey (Lethenteron camtschaticum)

Ichthyological Research ◽

10.1007/s10228-020-00757-3 ◽

2020 ◽

Author(s):

Hiroaki Arakawa ◽

Seiji Yanai

Keyword(s):

Thermal Tolerance ◽

Lethenteron Camtschaticum ◽

Arctic Lamprey ◽

Upper Thermal Tolerance

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

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f89-120 ◽

1989 ◽

Vol 46 (6) ◽

pp. 932-940 ◽

Cited By ~ 23

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.

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

ICES Journal of Marine Science ◽

10.1093/icesjms/fsw197 ◽

2016 ◽

Vol 74 (4) ◽

pp. 1033-1041 ◽

Cited By ~ 8

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.

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