Showing papers on "Holothuria published in 1992"

On the association between the crab Hapalonotus reticulatus (Crustacea, Brachyura, Eumedonidae) and the sea cucumber Holothuria (Metriatyla) scabra (Echinodermata, Holothuridae)

Abstract: Portunidae (genus Lissocarcinus) (for a review see JANooux, 1987). The Portunidae are exosymbionts, which A study of the fauna associated with holothurians from Hansa Bay live on the integument of the holothurian, while the (Papua New Guinea) reveals a new symbiotic association between the Pinnotheridae are endosymbionts, which generally live holothuroid Holothuria (Metriatyla) scabra and the crab Hapalonotus reticulatus. All the collected holothurians were infested, but with only in the gut or in the respiratory trees of their hosts. one crab per holothurian, always in the right respiratory tree near the Previously Hapalonotus reticulatus (DE MAN, 1879) was cloaca. Because of its size, H. reticulatus considerably expands the known from only 3 female specimens (with membranawall of the respiratory tree, fanning a membranaceous cyst. This ceous carapaces) from Ambon and Banda. Nothing is association, therefore, appears to be parasitic. However, the crab does mentioned in the literature about the ecology of this not feed upon host tissue but seems to filter its food from water passing through the respiratory tree of its host. crab. Only BALSS (1933) suggested that the body shape The description of two males allows to comment upon the taxonomical of the crab could be the result of a commensal way of position of H. reticulatus. We classify H. reticulatus in the recently life. re-established family Eumedonidae. This is the first record of a species The discovery in Papua New Guinea of 6 specimens (2 of Eumedonidae living in association with a holothurian. Key-words : Symbiosis, taxonomy, crab, holothurian, Papua New males and 4 femeles) of H. reticulatus in specimens of Guinea. Holothuria (Metriatyla) scabra JAEGER, 1833, allows us ./ to describe the symbiotic relationship between H. reticulatus and H. (M.) scabra, and to elucidate the systematic Resume position of H. reticulatus. These findings were briefly reported upon at a colloqium Des observations realisees sur la faune associee aux holothuries de la in 1991 (VANDENSPIEGEL & OVAERE, in press), and are Hansa Bay (Papouasie Nouvelle-Guinee) ont permis de decrire une now described on full. nouvelle association entre 1'holothurie Holothuria (Metriatyla) scabra et Ie crabe Hapalonotus reticulatus. Toutes les holothuries recoltees etaient infestees. II n'y ajamais plus d'un crabe par holothurie. Chaque crabe est loge dans Ie poumon droit pres du cloaque. En raison de sa Materials and methods taille, H. reticulatus deforme considerablement la paroi du poumon pour former un kyste membraneux. En consequence, 1'association The specimens of Holothuria (Metriatyla) scabra were serait de type parasitaire. Cependant Ie crabe ne se nourrit pas aux depends des tissus de son hote. II semble plutot filtrer sa nourriture collected at depths of 6 to 11 m, by day, using SCUBA a partir de 1'eau qui circule dans Ie poumon de son hote. in Hansa Bay (Madang Province, Papua New Guinea) L'etude de deux specimens males a permis de preciser la position (Fig. 1). The holothurian population lives in a sparse taxonomique de H. reticulatus qui, jusqu'a present, etait incertaine. seagrass bed (Fig. 2) of Halophila and Halodule species Nous considerons H. reticulatus comme appartenant a la famille des Eumedonidae, recemment retablie. C'est la premiere fois qu'un crabe (BAY & DEMOULIN, 1989), which extends from 2 to 11 Eumedonidae est trouve en association avec une holothurie. m depth. The substrate is made up of volcanic black Mots-clefs : Symbiose, taxonomie, crabe, holothurie, Papouasie Nousand. velle-Guinee. The specimens of Hapalonotus reticulatus were re moved from holothurians, previously anaesthetized for 2 to 3 hours in a freezer, and immersed in a 2 % marine Introduction solution of propylene phenoxetol (Nippa Laboratories, UK; see HILL & REINSCHMID, 1976). The crabs were The number of symbiotic associations between crabs fixed in formalin and preserved in 70 % alcohol. For and holothurians are not numerous, and consists mainly of crabs belonging to the family Pinnotheridae (genera Ophistopus, Pinnixia, Pinnaxoda and Pinnotheres) and * Publication n° 254 of the King Leopold III Biological Station