Growth, reproductive cycle and penis shedding of Littorina littorea in the Ria de Aveiro (north-west Portugal)

Abstract

The growth and the reproductive cycle of Littorina littorea were investigated in the Ria de Aveiro, Portugal, a country cited as the southern limit of the species distribution in Europe. Littorina littorea growth is well represented by the von Bertalanffy equation SH=24.6[1-e-0.69(t-0.70)] where SH is the shell height (distance from shell apex to the basis of the aperture measured in mm) and t is the number of winters: after periwinkles have reached a mean SH of 4.6 mm in their first winter they grow progressively to about 14.6 mm, 19.6 mm, 22.1 mm and 23.4 mm in the following four years and they attain the asymptotic mean maximum SH of 24.6 mm at the tenth year if they survive. Ripening of the gonads occurred from October to May but was more intense from December to February, whereas spawning extended from January to May in females and November to May in males. There was a seasonal shedding of the male penis at the end of the breeding season (summer) accompanying regression of the testis.

Size matters: importance of penis length variation on reproduction studies and imposex monitoring in Bolinus brandaris (Gastropoda: Muricidae)

“…Seasonal variation in male PL (or even penis shedding at the end of breeding season) has been described in several marine gastropods. Besides B. brandaris, PL variation has been reported to occur in Haustrum scobina (Smith & McVeagh, 1991), Hexaplex trunculus (Vasconcelos et al, 2006), Littorina littorea (Grahame, 1969;Fretter & Graham, 1994;Davies & Minchin, 2002;Barroso et al, 2007;Van den Broeck et al, 2007, L. saxatilis (Berry, 1961), Nassarius incrassatus (Stroben et al, 1996), N. obsoletus (Jenner & Chamberlain, 1955;Jenner, 1979;Bryan et al, 1989;Oberdörster et al, 2005;Hotchkiss et al, 2008), N. reticulatus (Stroben et al, , 1996Barroso & Moreira, 1998), Nucella lapillus (Gibbs et al, 1987;Oehlmann et al, 1991;Stroben et al, 1996;Davies et al, 1997;Gibbs, 1999;Galante-Oliveira et al, 2010), Ocenebra erinacea (Stroben et al, , 1996, Thais clavigera (Li, 2005;Chan et al, 2008) and Trivia arctica (Stroben et al, 1996).…”

Seagrass is protected from ragworm pressure by a newly discovered grazer–ragworm interaction; implications for restoration

“…Their geographic distribution is mainly focused around the Northern Atlantic Ocean, but Platynereis has been found to show an almost cosmopolitan distribution with occurrences on all continents except Antarctica (http://gbif.org, accessed 2022). Reproduction of both species varies, due to their widespread distribution, but is known to occur between winter and spring in Europe (Barroso et al, 2007; Bedford & Moore, 1985).…”