Seasonal variation in fecundity, egg case viability, gestation, and neonate size for little skates, Leucoraja erinacea, in the Gulf of Maine
Landings of the little skate, Leucoraja erinacea, within the territorial waters of the United States are currently regulated by a federal fishery management plan (FMP). For a FMP to be effective, thorough knowledge of a species’ reproductive biology is essential. Currently, little information exists on annual fecundity, egg case viability, gestation length, and neonate total length, for the little skate in the Gulf of Maine. To study these reproductive parameters, mature skates and egg cases were housed in fiberglass tanks with an open seawater system that provided natural, seasonal fluctuations in water temperature. Egg case deposition was highest during summer months with a seasonal peak in June. Of the 324 egg cases laid by seven females (c. 46 eggs per year, per female), 74.1% were viable. Gestation lengths ranged from 22 to 54 weeks throughout the four seasons. Egg cases laid in the fall had the longest gestation times (44.9 weeks, ± 0.13 weeks) and those laid in the spring had the shortest gestation times (24.5 weeks, ± 0.21 weeks). Total lengths of neonates from spring oviposition were statistically the longest (10.74 ± 0.05 cm) when compared to neonates from other seasons; however, egg viability was statistically the lowest for spring when compared seasonally.
KeywordsRajidae k-selected Reproduction Fecundity Oviparous
We thank the University of New England’s Marine Science Center for the use of the wet lab facilities and Marie Quinlan and Jade Heidt for aiding in the maintenance and care of the specimens. MSC contribution number 33.
- Fahey DR (1993) Fecundity of the little skate, Raja erinacea, (Rajiformes: Rajidae). MS Thesis, University of MassachusettsGoogle Scholar
- Frisk MG (2004) Biology, life history, and conservation of elasmobranchs with an emphasis on western Atlantic skates. PhD Thesis, University of MarylandGoogle Scholar
- Holden MJ (1977) Elasmobranchs. In: Gulland JA (ed) Fish population dynamics. Wiley, New York, pp 187–215Google Scholar
- Johnson GE (1979) The ovarian cycle and fecundity of the little skate, Raja erinacea, in Block Island Sound, Rhode Island. MS Thesis, University of Rhode IslandGoogle Scholar
- McEachran JD (2002) Skates, Family Rajidae. In: Collette B, Klein-MacPhee G (eds) Bigelow and Schroeder’s fishes of the Gulf of Maine, 3rd edn. Smithsonian Institution Press, Washington, pp 60–75Google Scholar
- New England Fishery Management Council (2003) Skate fisheries management plan. New England Fishery Management Council, NewburyportGoogle Scholar
- Richards SW, Merriman D, Calhoun LH (1963) The biology of the little skate, Raja erinacea, Mitchill. Bull Bingham Oceanogr Collect 18:5–67Google Scholar
- Waring GT (1980) A preliminary stock assessment of the little skate, Raja erinacea, in the northwest Atlantic. MS Thesis, Bridgewater State CollegeGoogle Scholar