Thyroid hormone divergence between two closely related but ecologically diverse cyprinid fish species (Cyprinidae). (April 2015)

• Record Type: Journal Article
• Authors: Bolotovskiy, Aleksey A.; Levin, Boris A.
• Is Part Of: Biochemical systematics and ecology. Volume 59(2015)
• Page Start: 305
• Page End: 310
• Publication Date: 2015-04
• Subjects: Bentophagous -- Cyprinidae -- ELISA -- Seasonal variations -- Thyroid divergence -- Zooplanktivorous; Chemotaxonomy -- Periodicals; Biochemical variation -- Periodicals; Ecology -- Periodicals; Biochemistry -- Periodicals; Ecology -- Periodicals; Chimiotaxinomie -- Périodiques; Variation biochimique -- Périodiques; Écologie -- Périodiques; 578.012
• DOI: 10.1016/j.bse.2015.02.012
• Languages: English
• ISSNs: 0305-1978

Abstract

Abstract: Thyroid hormones (THs) are involved in regulation of many life history traits of fishes. Development, growth, reproduction and shaping the adult phenotypes were found to be regulated by THs. Regulatory evolution is one of the main factors driving morpho-ecological diversification and speciation. We tested a hypothesis whether closely related but ecologically diverged species may have a diverse level of THs. We compared seasonal levels of plasma concentrations of triiodothyronine (T3 ) in two cyprinid species, benthophagous bream Abramis brama and zooplanktivorous blue bream Ballerus ballerus . Significant differences in T3 concentrations were detected. B. ballerus had substantially reduced T3 levels as compared to most other species of fish. Two hypotheses explaining the thyroid divergence are discussed. Despite differences in absolute T3 concentrations, both species manifest similar seasonal cycling with increased plasma T3 levels in warmer seasons and decreased T3 in colder seasons. Several peaks of plasma T3 level were registered: at pre-spawning periods, at mid-summer and in the early autumn. The pre-spawning peak noted in cyprinids was a novel observation. Significant positive correlations were detected between water temperature and plasma T3 concentrations, as well as between the duration of daylight and T3 plasma concentrations in both species. Highlights: Divergent triiodothyronine (T3 ) level between closely-related species was detected. Despite divergence, an annual cycling of T3 variation was similar in both species. Changes in T3 pattern secretion might be responsible for evolution of these species.