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

Abstract

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.

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

“…A similar distribution pattern was noted in the eastern Murman coastal waters [37]. The predominance of new-shell individuals is explained by frequent molting events in juvenile red king crabs (2-4 times per year) which would not be expected to have old shells [58][59][60].…”

Sublethal Biochemical Effects of Polyethylene Microplastics and TBBPA in Experimentally Exposed Freshwater Shrimp Palaemonetes argentinus

“…The neuroendocrine cells of decapod crustaceans located in hormone secretion tissues can secrete numerous hormones, the release of which into the hemolymph plays key regulatory roles in the ontogenetic development of organisms [ 53 , 54 ]. In decapod crustaceans, the thyroid hormones thyroxine and triiodothyronine play a pivotal role in regulating metabolism and metamorphosis [ 25 ]. Recently, Dvoretsky et al [ 25 ] reported that both thyroid hormones were detected in the red king crab Paralithodes camtschaticus hemolymph.…”

“…In decapod crustaceans, the thyroid hormones thyroxine and triiodothyronine play a pivotal role in regulating metabolism and metamorphosis [ 25 ]. Recently, Dvoretsky et al [ 25 ] reported that both thyroid hormones were detected in the red king crab Paralithodes camtschaticus hemolymph. The authors’ findings confirm that TH levels changed significantly depending on the age of crabs and sampling season, and therefore are involved in the specific physiological mechanisms [ 25 ].…”

“…The biotransformation of xenobiotics may contribute to the increased production of reactive oxygen species that are potentially toxic for crustacean species such as Daphnia magna [ 24 ]. On the other hand, it has been reported that thyroid hormones (THs) play a key role in development, metamorphosis, and crustacean metabolism [ 25 ]. However, data on the xenobiotic disruption (e.g., by PEM or TBBPA) of thyroid signaling in freshwater crustaceans are unknown so far.…”

Ecology and Distribution of Red King Crab Larvae in the Barents Sea: A Review

“…Many aspects of the RKC biology, ecology, fisheries, aquaculture, and management have been intensively studied and reviewed [23][24][25]27,[29][30][31][32][33][34][35]41,42,[44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63]. The larvae of RKC exist during the spring period and they occur in the plankton during 8-10 weeks and then settle to the bottom [29].…”