Description d'une suceuse à air comprimé économique et utilisable par un seul plongeur = Description of a sucking-pipe sampler

A new type of sucking pipe sampler is described, using a scuba diving-tank for air-lift. A series of samplings may be performed by one single diver during one single diving

Morphology of the <i>Buccal apparatus</i> and related structures in four species of Carapidae

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 Al 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

Morphological particularities of the head in four Carapidae (Ophidiiformes)

A study of the skull and the musculature of the oral and pharyngeal region of four adult Carapidae species (Encheliophis boraboreruis, E. homei. E. gracilis and Carapus acus) has been undertaken to compare it with the diet related characters. The cephalic organization of E. boraborensis and E. gracilis seems related to diet (mainly fishes and shrimps for the first one and holothurian tissues for the other): these species are respectively commensal and parasitic. Although the feeding characters of E. homei and C. acus are closely similar to those of E. boraborensis, there are sparse observations of holothurian tissues in their stomach contents. It is suggested that these fishes are commensal when they are adults and have parasitic tendency when they are juveniles

The Seascape as an Indicator of Environmental Interest and Quality of the Mediterranean Benthos: The in Situ Development of a Description Index: The LIMA

peer reviewedThe LIMA index conveys the environmental interest and quality of the landscape formed by the Mediterranean benthos, ranging from 0 to − 40 m, in numerical format. The LIMA index allows a comparison spatially and temporarily between sites. It is a comprehensive index which is easy to implement and is composed of two factors: a topographical description (classification of 15 typologies) and a biological description (the presence or absence of some thirty species or groups of structuring, remarkable and invasive species). The LIMA index has been validated in he Bay of Calvi (Corsica-France) where it varies between 0.31 and 0.79 on a scale of 0.00–1.00

Stimulation of the potential heterotrophic activity in deep seawater by barotolerant bacteria colonizing faecal pellets produced by migrating zooplankton.

International audienceAt a depth of 1 150 m in the northwest Mediterranean, amino acid uptake and bacterial biomass production rates increased, in a 12-day lime interval, 5- and 30-fold, respectively. Simultaneously, bacterial response to pressure changes evolved from barophilic to barotolerant. During the same period, scanning electron microscope observations and in situ observations using Underwater Video Profiler showed a 2-fold increase in particle concentrations, mainly due to faecal pellet production by zooplankton. This input, nutrient rich and largely colonized with bacteria unaffected by pressure variations since they originated from organisms that regularly migrate up and down through the water column, could produce such microbial activity peaking in the deep water masses. (C) 1999 Academie des sciences/Editions scientifiques et medicales Elsevier SAS

Comparative value of chitosan test and enzymatic method for chitin detection

In oorder to check their relative value for the specific identification of chitin on minute pieces of skeletal material, the chitoisan test of Campbell, readapted by Krishan and Sundara-Rajulu and the enzymatic method of Jeuniaux using purified chitinases, were applied simultaneously to the same material. In most cases, both methods gave similar results, the chitosan test being more rapid and useful to locate chitin in composite structures. In two specific cases, these methods yielded contractory results. Fragments of Rhabdopleura sp exoskeleton (Pterobranchia), after alkali treatment, gave a more or less typical colour with chitosan tests, but remained unaltered in pure chitinase solutions without N-acetyl-D-glucosamine production. In the same manner, hooks of Cloesiphon sp (Sipunculida) gave a positive reaction to chitosan test but failed to dissolve in pure chitinase, after repeated incubations at 37°C. It is concluded that, in some cases, undetermined organic substances, which do not correspond to true chitin, may be interpreted as chitin with chitosan test