Reproductive biology ofMegabalanus azoricus(Pilsbry), the Azorean Barnacle

Abstract

SummaryThe reproductive biology of Megabalanus azoricus (Pilsbry), the commercially exploited barnacle in the Azores, was studied in an attempt to provide the scientific basis for the sustainable management of this heavily exploited regional marine resource. Both the Ospar Commission and WWF have expressed concern for this species, considering it at risk and in urgent need for scientific study. Barnacles were collected every month from shallow water (.3 m depth) around São Miguel Island from October 2004 to September 2005. Individuals were measured and gonads processed for histology and analysed with a stereological method. M. azoricus has a hermaphroditic reproductive system with separate gonads and it was possible to describe the various stages of gametic maturation in both. Data on fertility were also obtained by egg counts and calculation of the Gonadosomatic index (GSI). Throughout the year, some specimens of M. azoricus can be found that rare mature, but two reproductive peaks were observed, one in January and a smaller one in July. A strong positive correlation between GSI and environmental factors such as photoperiod and water temperature was observed.

Dynamic models applied to giant barnacle culture

“…The results obtained indicate the importance of carrying out a daily census of competent larvae. In intertidal and subtidal acorn barnacles, there is considerable evidence of high temporal variation in reproduction and larval settlement (Hawkins and Hartnoll 1982;Miron et al 1996;Berntsson et al 2000;Jenkins et al 2000;Dionisio et al 2007;Jacinto and Cruz 2008;Satheesh and Godwin 2008;Kado et al 2009), ranging from interannual variations generated by periodic events to differences between tidal cycles. In contrast, intense larval settlements in barnacles can generate high early mortality among recently settled individuals, as a result of density-dependent processes (Bertness 1989;Hills and Thomason 2003).…”

Economic Feasibility of Aquaculture of the Giant BarnacleAustromegabalanus psittacusin Southern Chile

“…Only A. psittacus has been cultured on a semi-industrial scale in southern Chile (Lo´pez 2008, Lo´pez et al 2010. Spat collection for the ''craca'' Megabalanus azoricus (Dionisio et al 2007, Pham et al 2008 has also been undertaken on a trial basis. Distribution of A. psittacus ranges from Peru to the Strait of Magellan, including the Juan Ferna´ndez archipelago, and southern Argentina (Young 2000, Pitombo & Ross 2002, Lo´pez et al 2007b).…”

Potency of Barnacle in Aquaculture Industry

“…Future projections for barnacle culture are aided by the wide-ranging and diversified literature available on larval development in various species; specifically, on aspects such as: duration, effects of environmental factors and feeding, as well as ecological, physiological and behavioural factors associated with larval settlement and recruitment (Walker, 1995;Jenkins et al, 2000;Dionisio et al, 2007;Tremblay et al, 2007;Pineda et al, 2009). Although this information is mainly related to species that are not commercially important, it can be used to optimize barnacle culture.…”

“…Larval development, and the factors that influence it, has been studied in various species of lepadomorphs and balanomorphs (Miller et al, 1989;Molares et al, 1994;Yan & Chan, 2001;Dionisio et al, 2007;Li et al, 2011).…”