|
|
|
|
|
| Guillou, M. |
| Massive outbreaks of starfish (Asteridae) occur periodically in European coastal waters. The origins of these irregular population increases are poorly understood. In the subtidal zone of the Bay of Douamenez, Brittany, France, the occurrence of several species of Asteridae and the polymodal size distribution differentiate these aggregations from the single year-class and monospecific intertidal infestations. An echinoderm population survey from 1982 to 1988 showed an increase in carnivorous starfish (principally Asterias rubens and Marthasterias glacialis) from 1981 to 1984, when the population reached carrying capacity. At this time, a trophic imbalance between starfish and bivalves was observed. From 1985 onward, the total echinoderm biomass decreased... |
| Tipo: Text |
|
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00096/20752/18379.pdf |
| |
|
| |
|
|
| Dodin, A; Dosso, M; Guillou, M. |
| There exists no biochemical test allowing to define the pathogenicity of a bacterium, still less for a Vibrionaceae. Two essential characters are to be retained to hold responsible an isolated germ, for an illness: 1) the binding factor, the identification is difficult but a double diffusion of agar should simplify the method; 2) the search for the choleric toxin or a common part of the choleric toxin (toxin LT or ST of E. coli ). Here again, simplified techniques may be used. The acquirement of a plasmid responsible for the binding factor or for the toxin production of the non-pathogenic Vibrionaceae in the origin of certain epidemic diseases in France and in the world. Frequently, epidemics due to common germs (Aeromonas hydrophila of Africa) lead to... |
| Tipo: Text |
Palavras-chave: Aeromonas hydrophila; Vibrionaceae; Bacteria; Ecology; Microorganisms; Hosts; Bacterial diseases; Pathogenic bacteria. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-999.pdf |
| |
|
|
| Guillou, M; Michel, C. |
| In Brittany, the edible sea-urchin Sphaerechinus granularis (Lamarck) is at the northern limit of its range. Small-scale exploitation of this species occurs in the Glenan islands, in the bay of Concarneau (Finistere, France). Three extensive diving surveys undertaken in 1990, 1991 and 1992 show a significant variation of the stock which was estimated at between 700 and 1400 tonnes during this study. The constant level of the annual sea-urchin harvest suggests that these fluctuations may be attributed to variation in recruitment. This can be considered as non-existent in 1989 and 1992, substantial in 1990 and moderate in 1991. The causes of this variability are complex. It is certainly directly related to the phenology of the reproductive cycle (recruitment... |
| Tipo: Text |
Palavras-chave: SPHAERECHINUS-GRANULARIS; ATLANTIC COAST; RECRUITMENT; STOCK. |
| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00100/21138/18758.pdf |
| |
|
|
| Glemarec, M; Guillou, M. |
| Do post-larval recruitment and year-class segregation constitute a response to abiotic and biotic factors? Avoiding the traditional controversy about conditions in rocky and soft bottom conditions, the authors describe several examples where year-class segregations are evident in soft bottoms, taken from different trophic guilds of echinoderm populations on the coast of Brittany: suspension feeders, herbivorous and carnivorous populations. Physical factors such as fronts or gyres can concentrate larvae and nutritive particles for suspension-feeder populations. These factors are, on the other hand, conducive to the establishment and persistence of stable populations in time. The cohorts being long-lived, the oldest classes are very abundant and, as a... |
| Tipo: Text |
|
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00094/20496/18165.pdf |
| |
|
|
|
