Reproductive biology and energy allocation of the sea star Cosmasterias lurida (Echinodermata: Asteroidea) from the Beagle Channel, Tierra del Fuego, Argentina

COSSI, PAULA FANNY; BOY CLAUDIA; GIMÉNEZ JULIANA; PEREZ, ANALÍA FERNANDA

POLAR BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2015

0722-4060

Abstract Seasonal fluctuations in environmental factors athigh-latitude marine regions have a strong influence on thereproductive cycles of echinoderms. The purposes of thisstudy on a population of Cosmasterias lurida in the BeagleChannel are to describe the reproductive cycle through histologicalanalyses, to characterize the pattern of gonad andsomatic indices, to determine the energy content of differentorgans and their temporal variation and to establish the patternof energy allocation. During the study period, from August2010 to June 2011, four seasonal samplingswere performed inthe subtidal zone of Ushuaia Bay. Indices (gonad, pyloriccaeca and stomach), gonadal histology, organic matter andcalorimetric measurements were determined. Gametogenesisbegins in February and continues until June when oocyte sizeincreases. The gonadal maximum development and gametereleasing take place between August and December. Temporalvariation of energetic reserves in gonads occurs throughthe variation in gonad mass, with a GI major peak and energycontent during August. Stomach and pyloric caeca show theirmaximum energy accumulation during June, while decreaseof organic matter of the body wall takes place from August toDecember. The population of C. lurida from Beagle Channelsuggests an annual reproductive cycle with two maturationevents and the influence of water temperature on maturationand releasing of gametes. Different patterns of energy allocationto gonads between sexes were observed, with a greaterenergy investment in females than in males. Pyloric caeca,stomach and bodywall were proposed as energy reservoirs forgonadal maturation and spawning.