Associated fauna and effects of epibiotic barnacles on the relative growth and reproductive indices of <em>Stramonita haemastoma</em> (Gastropoda: Muricidae)

Abstract

Summary:To better understand the impacts of biofouling on the biological processes of the basibiont, the effects of epibiotic barnacles on the relative growth and reproductive indices of Stramonita haemastoma (Linnaeus, 1767) were assessed. A total of 1035 specimens were collected monthly for one year from Bizerta Channel (northern Tunisia). Endobiotic species comprised the lithophagous bivalves Lithophaga aristata and Rocellaria dubia of different sizes, communicating with the outside through tiny perforations. Intra-shell tunnels and galleries also sheltered annelids and sipunculids. Epibiotic species comprised algae and highly diversified invertebrates represented by crustaceans, polychaetes, molluscs, echinoderms, ascidians, sponges, bryozoans and sipunculids, with barnacles being the most common group. Comparison of growth features between non-fouled and fouled S. haemastoma revealed higher growth in non-fouled specimens. Differences in reproductive condition indices were detected in few months, being mostly higher in non-fouled snails, but showed no asynchrony in the spawning period for either fouled or non-fouled gastropods hosts. Resumen: Para mejorar la compresión de los impactos del biofouling en los procesos biológicos de los basibiontes, se ha evaluado los efectos de los balanos epibiontes en el crecimiento relativo y en los índices reproductivos de Stramonita haemastoma (Linnaeus, 1767). Se recogieron un total de 1032 especímenes mensualmente, durante un año, en el canal de Bizerta (norte de Túnez). Las especies endobióticas estaban compuestas por los bivalvos litófagos Lithophaga aristata y Rocellaria dubia, de diferentes tamaños, que se comunicaban con el exterior a través de pequeñas perforaciones. Los túneles y galerías del interior de la concha también albergaban anélidos y sipuncúlidos, siendo los balanos el grupo más común. La comparación del crecimiento entre los gasterópodos con y sin fouling mostró un mayor crecimiento en los S. haemastoma sin fouling. Las diferencias en los índices reproductivos se detectaron en pocos meses, siendo mayor en los caracoles no invadidos por el fouling, pero ninguno de los gasterópodos hospedadores mostró asincronía en el periodo de desove.

Shell Infestation of the Farmed Pacific Oyster Magallana gigas by the Endolith Bivalve Rocellaria dubia

“…Until now, it has been reported as a borer in the shells of bivalves O. edulis [2,3,10,38,39], Spondylus sp. [3], Pinna nobilis Linnaeus, 1758 [2,3,38], Venus verrucosa Linnaeus, 1758 [2,19], Glycymeris nummaria (Linnaeus, 1758) [2], Arca noae Linnaeus, 1758 [17], Modiolus barbatus (Linneaeus, 1758) [14,17], M. galloprovincialis Lamarck, 1819 [40,41], Pseudochama gryphina (Lamarck, 1819) [17], Mimachlamys varia (Linneaeus, 1758) [17], and gastropode Stramonita haemastoma (Linnaeus, 1767) [18]. Oysters are well known to host different epibiontic and endobiontic invertebrates [20][21][22][23][24][25][26].…”

“…The species is very common and widely distributed in the Adriatic Sea, boring in infralittoral rocks of carted limestone, coralligenous biogenic outcrops, and other biogenic structures, as well as artificial concrete blocks [2,[14][15][16][17]. R. dubia perforates skeletons and shells of different dead and live marine organisms, such as stone corals [5,17], coralline algae [5], echinoderms [6], gastropods [18], and bivalves [2]. Some studies suggest a negative impact of this borer on host bivalves [19].…”