Hemolymph molting hormone concentrations in red king crabs from the Barents Sea

2022

Diversity

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The invasive red king crab, Paralithodes camtschaticus, has become an abundant and important component in the food web of the coastal Barents Sea and can affect the structure and functioning of the local benthic communities through competition and predation. Although dietary composition and feeding behavior of the crab have been intensively studied, prey selectivity in this species under natural conditions remains poorly defined. For this reason, juvenile red king crabs and benthic samples were collected simultaneously at five coastal sites in Kola Bay to reveal the species composition and structure of feeding habits and the diet of red king crabs. The results of stomach and gut content analyses coupled with calculated Ivlev’s indices indicated that 2–5-year-old crabs frequently consumed bivalve mollusks in relative proportions to prey field biomasses. At all sites, juveniles selectively rejected polychaetes. In soft-bottom communities, when the average density of Bivalvia decreased, the crabs showed increased preference for Gastropoda, Crustacea, and Echinodermata. As a result of selective feeding focused on infaunal suspension-feeding mollusks, juvenile red king crabs have altered the structure of benthic communities in the mouth of Kola Bay. Our results may have important implications for evaluating the consequences of the crab introduction and its population management.

Section: Red King Crabssupporting

confidence: 73%

Prey Selectivity in Juvenile Red King Crabs from the Coastal Barents Sea

Павлова

2022

Diversity

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“…The red king crab is a slow-growing species reaching the commercial size of 150 mm carapace width (or 137 mm carapace length) after 10 years of growth. Potential methods to decrease inter-molt intervals and improve growth performance of crustaceans include manipulation of their hormonal status by administration of steroid hormones [37,39,55] or double-stranded RNA (dsRNA) [56], dietary supplementation [50,51], and other methods [43]. Thyroid hormones may also be considered promoting agents for cultivation of Paralithodes camtschaticus.…”

Section: Discussionmentioning

confidence: 99%

“…Although many life-history traits of the Barents Sea red king crabs are well-studied [19][20][21][22][23][24][29][30][31][32][33][34][35][36], there is a lack of knowledge on their physiology, especially, hormone profiles in the hemolymph [37][38][39]. Recently, the presence of thyroid hormones has been reported in red king crabs [40], but those data are restricted and more detailed information is required for further research, monitoring, and aquaculture purposes.…”

Section: Introductionmentioning

confidence: 99%

Thyroid Hormones in Hemolymph of Red King Crabs from the Barents Sea

Типисова

Popkova

et al. 2022

Animals

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Only a few studies have reported the presence and levels of thyroid hormones in invertebrates. At the same time, the administration of these hormones has been shown to be a profitable method for inducing growth in crustaceans. Knowledge of thyroid hormone concentrations is required to involve this approach in crustacean aquaculture. For this reason, we examined hemolymph samples of the invasive red king crab Paralithodes camtschaticus from the Barents Sea population for the levels of triiodothyronine (T3) and thyroxine (T4). Radioimmunoassays indicated that T3 ranged from 0.26 to 1.55 μg dL–1, whereas T4 varied from 52 to 203 μg dL–1. Adult crabs demonstrated higher levels of T3 than juveniles, while juvenile crabs had higher levels of T4 in comparison to larger conspecifics. The thyroxine levels were consistent throughout the study period. In contrast, significant seasonal variations were found for T3. In immature crabs, the maximum concentration was found in October, whereas in adult crabs, the highest level of T3 was registered in August. Most likely, these results are explained by changes in physiological conditions of the crabs associated with their molting calendar and migration activity. Our data may have important implications for aquaculture of Paralithodes camtschaticus in the Barents Sea.

“…The population dynamics and aquaculture approaches to red king crab in the Barents Sea have been extensively studied and developed due to the species' high commercial value and introduced status (Dvoretsky and Dvoretsky 2010c, 2013b, 2014a, b, 2015. Dynamics of the total and commercial stock of red king crabs have been assessed based on trawl survey data (Fig.…”

Section: Red King Crabmentioning

confidence: 99%

Commercial fish and shellfish in the Barents Sea: Have introduced crab species affected the population trajectories of commercial fish?

Rev Fish Biol Fisheries

2015

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The Barents Sea shelf system, particularly the southwestern, western and southern parts, is one of the most productive ocean regions in the world due to the influence of warm Atlantic water. We conducted an analysis of long-term data based on original and published sources focused on the trends in abundance of key commercial species in the Barents Sea. We specifically examined the patterns and characteristics of both invasive species and invasion processes, using the example of two introduced crabs: the red king crab (Paralithodes camtschaticus) and the snow crab (Chionoecetes opilio), which in polar ecosystems may provide an important case study for improving our ability to predict the impact of new invaders. Warm temperature anomalies were observed in the