Abstract
The smooth skate, Malacoraja senta, and thorny skate, Amblyraja radiata, are two commercially exploited batoids found within the Gulf of Maine. During the past five years, we conducted a large study to accurately describe important biological life history parameters previously lacking for these species. As part of that project, the current study reports our findings on the hormonal profiles associated with the reproductive cycles of M. senta and A. radiata. Blood samples were obtained from mature M. senta and A. radiata of both sexes from all months of the year, and plasma testosterone (T), estradiol (E2) and progesterone (P4) concentrations were determined using radioimmunoassay (RIA). In female M. senta and A. radiata, monthly T concentrations ranged from 4,522 pg ml−1 to 1,373 pg ml−1 and 31,940 pg ml−1 to 14,428 pg ml−1, E2 concentrations from 831 pg ml−1 to 60 pg ml−1 and 8,515 pg ml−1 to 2,902 pg ml−1, and P4 concentrations from 3,027 pg ml−1 to 20 pg ml−1 and 3,264 pg ml−1 to 331 pg ml−1, respectively. No statistical differences were detected between any months for any hormone. Estradiol concentrations were not correlated with ovary weight, shell gland weight, or diameter of the largest follicles in either species. Monthly T concentrations in male M. senta and A. radiata ranged from 23,146 to 12,660 pg ml−1 and from 57,500pg ml−1 to 24,737 pg ml−1, while E2 concentrations ranged from 7.5 pg ml−1 to undetectable and 103 to 30 pg ml−1, respectively. No statistical differences were observed between months for either steroid. Testosterone concentrations were weakly correlated with testes weight and percent of stage VI spermatocysts in A. radiata, however, no correlation was detected between T and stage VI spermatocysts in M. senta. Collectively, these data support the previous conclusion that M. senta and A. radiata of both sexes are capable of reproducing year round in the western Gulf of Maine.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Goldberg MJ, Moses M, Tsang PCW (1996) Identification of matrix metalloproteinases and metalloproteinase inhibitors in bovine corpora lutea and their variation during the estrous cycle. J Anim Sci 74:849–857
Heupel MR, Whittier JM, Bennett MB (1999) Plasma steroid hormone profiles and the reproductive biology of the epaulette shark, Hemiscyllium ocellatum. J Exp Zool 284:586–594
Koob TJ, Tsang PCW, Callard IP (1986) Plasma estradiol, testosterone and progesterone levels during the ovulatory cycle of the little skate, Raja erinacea. Biol Reprod 35:267–275
Manire CA, Rasmussen LEL, Hess DL, Hueter RE (1995) Serum steroid hormones and the reproductive cycle of the female bonnet head shark, Sphyrna tiburo. Gen Comp Endo 97:366–376
Maruska KP, Cowie EG, Tricas TC (1996) Periodic gonadal activity and protracted mating in elasmobranch fishes. J Exp Zool 276:219–232
Natanson LJ, Sulikowski JA, Kneebone J, Tsang PCW (this volume) Age and growth estimates for the smooth skate (Malacoraja senta) in the western Gulf of Maine. Envir Biol Fish
New England Fisheries Management Council (NEFMC) (2005) Skate Annual Review. National Marine Fisheries Service, February 2005
Rasmussen LEL, Gruber SH (1993) Serum concentrations of reproductively related circulating steroid hormones in the free ranging lemon shark, Negaprion brevirostris. Envir Biol Fish 38:167–174
Rasmussen LEL, Hess DL, Luer CA (1999) Alterations in serum steroid concentrations in the clearnose skate, Raja eglanteria: correlations with season and reproductive status. J Exp Zool 284:575–585
Snelson FF Jr, Rasmussen LEL, Johnson MR, Hess DL (1997) Serum concentrations of steroid hormones during reproduction in the Atlantic stingray, Dasyatis sabina. Gen Comp Endo 108:67–79
Sulikowski JA, Tsang PCW, Howell WH (2004) An annual cycle of steroid hormone concentrations and gonad development in the winter skate, Leucoraja ocellata, from the western Gulf of Maine. Mar Biol 144:845–853
Sulikowski JA, Kneebone J, Elzey S et al (2005a) Age and growth estimates for the thorny skate (Amblyraja radiata) in the western Gulf of Maine. Fish Bull 103:161–168
Sulikowski JA, Kneebone J, Elzey S et al (2005b) The reproductive cycle of the thorny skate (Amblyraja radiata) in the western Gulf of Maine. Fish Bull 103:536–543
Sulikowski JA, Elzey S, Kneebone J et al (2007) The reproductive cycle of the smooth skate (Malacoraja senta) in the western Gulf of Maine. J Mar FW Res 58:98–103
Sumpter JP, Dodd JM (1979) The annual reproductive cycle of the female lesser spotted dogfish, Scyliorhinus canicula, and its endocrine control. J Fish Biol 15:687–695
Tricas TC, Maruska KP, Rasmussen LEL (2000) Annual cycles of steroid hormone production, gonad development, and reproductive behavior in the Atlantic stingray. Gen Comp Endo 118:209–225
Tsang PCW, Callard IP (1982) Steroid production by isolated skate ovarian follicular cells. Bull Mt Desert Island Biol Lab 22:96–97
Tsang PCW, Callard P (1987) Morphological and endocrine correlates of the reproductive cycle of the aplacental viviparous dogfish, Squalus acanthias. Gen Comp Endo 66:182–89
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2007 Springer Science+Business Media B.V.
About this chapter
Cite this chapter
Kneebone, J., Ferguson, D.E., Sulikowski, J.A., Tsang, P.C.W. (2007). Endocrinological investigation into the reproductive cycles of two sympatric skate species, Malacoraja senta and Amblyraja radiata, in the western Gulf of Maine. In: Ebert, D.A., Sulikowski, J.A. (eds) Biology of Skates. Developments in Environmental Biology of Fishes 27, vol 27. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-9703-4_10
Download citation
DOI: https://doi.org/10.1007/978-1-4020-9703-4_10
Publisher Name: Springer, Dordrecht
Print ISBN: 978-1-4020-9702-7
Online ISBN: 978-1-4020-9703-4
eBook Packages: Biomedical and Life SciencesBiomedical and Life Sciences (R0)