Distribución y estructura poblacional del cangrejo Halicarcinus planatus (Brachyura, Hymenosomatidae) en el Canal Beagle, Tierra del Fuego

DIEZ, MARIANO J.; FLORENTÍN, OLGA; GUSTAVO ALEJANDRO LOVRICH

REVISTA DE BIOLOGIA MARINA Y OCEANOGRAFIA

INST OCEANOLOGIA

Año: 2011 vol. 46 p. 141 - 155

0717-3326

The crab Halicarcinus planatus is the only hymenosomatid that inhabits the southern tip of South America and has a sub-Antarctic distribution, including the peri-Antarctic islands and New Zealand. In this paper, we report about abundance and population structure of H. planatus during a year in the intertidal of Bahía Brown, Beagle Channel, Tierra del Fuego. Moreover, we show variations in the population structure in other beaches and environments of the channel. In contrast with males, females density showed monthly variations and was higher during summer months. High densities of H. planatus could be related with low mortality of larval stages and oceanographic features of Bahía Brown, probably enhanced for the presence of both culture and mussel beds, substrates where settlement would occur. Populational sex proportion was biased towards females only in summer, while the operative sex proportion was male biased during all studied period, suggesting a strong competition between males for mating. In turn, males were present only in the intertidal of Bahía Brown and Macrocystis pyrifera but were absent in the other studied intertidals, perhaps related with the shelter absence in the subtidal of Bahia Brown. Recruitment occurs in two different periods, summer (January-February) and autumn-winter (May-June), which corresponds with the two larval cohorts of H. planatus in the Beagle Channel.