Food sources of two detritivore amphipods associated with the seagrass Posidonia oceanica leaf litter

in Marine Biology Research (2006), 2(5), 355-365

This study focused on the ingestion and assimilation of Posidonia oceanica (L.) Delile litter by Gammarella fucicola Leach and Gammarus aequicauda Martynov, two dominant detritivore amphipods of the P ... [more ▼]

This study focused on the ingestion and assimilation of Posidonia oceanica (L.) Delile litter by Gammarella fucicola Leach and Gammarus aequicauda Martynov, two dominant detritivore amphipods of the P. oceanica leaf litter. Scanning electron microscope observations indicated that leaf litter is highly colonized by diverse diatoms, bacteria and fungi, which may constitute a potential food source for the litter fauna. Gut content observations demonstrated that these species eat P. oceanica litter, and that this item is an important part of their ingested diet. Stable isotope analyses showed that the species do not experience the same gains from the ingested Posidonia. Gammarella fucicola displayed isotopic values, suggesting a major contribution of algal material (micro- and macro-epiphytes or drift macro-algae). On the other hand, the observed isotopic values of G. aequicauda indicated a more important contribution of P. oceanica carbon. The mixing model used agreed with this view, with a mean contribution of P. oceanica to approximately 50% (range 40-55%) of the assimilated biomass of G. aequicauda. This demonstrated that the two species, suspected to be detritus feeders, display in reality relatively different diets, showing that a certain degree of trophic diversity may exist among the detritivore community of the seagrass litter. [less ▲]

Analyse fonctionnelle des peuplements bactériens associés aux scléractiniaires

in Les récifs coralliens. 2ème partie : Aspects biologiques (2000)

Morphology of the buccal apparatus and related structures in four Carapidae

in Australian Journal of Zoology (1998), 46(3), 391-404

The aims of this study were (1) to compare the morphology of the buccal apparatus, the suspensorium and the opercle in four species of Carapidae (Carapus acus, Encheliophis boraborensis, Encheliophis ... [more ▼]

The aims of this study were (1) to compare the morphology of the buccal apparatus, the suspensorium and the opercle in four species of Carapidae (Carapus acus, Encheliophis boraborensis, Encheliophis homei and Encheliophis gracilis) and (2) to investigate the relationships between their cranial anatomy, their carnivorous diet, and their well known ability to enter holothurians. The complex and strong dentition and the wide hyomandibular with thickenings that seem to suit the constraints of the adductor mandibulae muscles partly inserted on the neurocranium are signs of a carnivorous diet. C. acus, E. boraborensis and E. homei have extremely strong buccal pieces and can protrude their upper jaws. However, in E. gracilis, the jaws are more slender, and the insertions of the A 1 along the entire length of the maxillary associated with the lack of mobility between the maxillary and the premaxillary prevent buccal protrusion. These differences could be related to the diet: C. acus, E. boraborensis and E. homei can feed on fishes and crustaceans, whereas E. gracilis feeds only on holothurian tissue. The cephalic morphology of the four species is not incompatible with entering the host. However, the neutralisation of the suboperculum spine by ‘cartilaginous’ tissue could be considered to be a particular adaptation to this behaviour. [less ▲]

Anatomical and functional particularities of the head in four carapid species

Poster (1997)

SEM control on the effect of different techniques used to remove epiphytes from seagrasses

in Aquatic Botany (1995), 52