Annales des Sciences Naturelles - Zoologie et Biologie Animale最新文献

In French Guiana, spider and howling monkeys exhibit significant differences in their locomotor and postural habits. This paper presents some qualitative and quantitative data on the forelimb muscles of howling and spider monkeys associated with the movements of the forelimb involved in these positional modes. In red howlers, m. supraspinatus functions as the main humeral abductor during clambering and climbing. In contrast, m. deltoideus is the main humeral abductor involved in climbing and arm-swinging activities in spider monkeys. Both atelines possess well-developed mm. latissimus dorsi, pectorales, and dorsoepitrochlearis, all associated with forelimb movements involved in frequent climbing and clambering. Howlers are similar to capuchins in distal forelimb muscle morphology that favors pronograde quadrupedal activities. On the other hand, spider monkeys possess well-developed elbow flexors and supinator which favor arm-suspensory behavior. Moreover, the similarity of the extrinsic digital flexor musculature between spiders and hylobatids underlines the important role of these muscles during arm-swinging and clambering.

Using UV light in order to study accumulation of BaP or 3MC by Gomphocerus sibiricus, a locust strictly located between 2 000 and 2 800 m, we have previously shown that these HAP can be rapidly absorbed by midgut, then, accumulated in many organs and essentially eliminated by Malpighian tubules (J.B., 1999), presumably after partial degradation. Now we describe the effects of these carcinogenic polycyclic hydrocarbons at histological and cytological levels. Wholly invaded, midgut epithelium is profoundly intoxicated, numerous cells showing structural abnormalities or beeing destroyed: excessive merocrine secretion becoming finally holocrine. Connective and muscular tissues do not constitute effective barriers against toxic effects of the HAP. Fat body and muscles, though strongly impregnated with each of them, show only discrete cellular damage. Locally, the reproductive system is more clearly affected. Otherwise, nervous cord ganglia contain some dead cells, and we describe an effective swelling of the intercellular spaces. This point seems to imply disturbancies of the glial sheats which isolate neurons from their neighbours. Finally, digestive caeca, strongly affected by HAP, are partly destroyed, especially after treatment by BaP. We suggest caeca could be a secondary route of degradation and excretion of HAP. Tubes of Malpighi seem to be the principal route of their elimination; their epithelium is frequently severely injured and may sometimes disappear. As with mammals, we have to underline here similar differential cell susceptibilities within each organ of a locust. However what may be, we have perceived effective disturbancies which are strong enough to involve a knock-down and finally death of a part of the treated locusts. This work gives us new opportunities for ulterior research, for example, with locusts sampled in a variety of biotopes, strongly polluted or “not”. Our UV test may be used as a first approach.

This is the first description of the embryonic development of an agamid lizard from North Africa, Agama impalearis. The developmental stages of only one species of the same family, Calotes versicolor, had been described previously. Two complementary studies had been performed on this Asian species, one dealing with intra-oviductal development, the other with extra-oviductal development. Among other iguanians, several cameleonid species and only two American iguanid species had apparently been examined. The other previous studies dealt with some species among the Lacertidae (complete or partial embryonic development), Scincidae, Cordylidae and Anguidae (partial embryonic development). In the present table, 42 stages have been distinguished during the embryonic development of A. impalearis. Stages 1 to 27 correspond to intra-oviductal development including egg segmentation, gastrulation, neurulation and the beginning of organogenesis. Stages 28 to 42 describe morphological changes during extra-oviductal development, i.e. between egg-laying and hatching, and correspond to the continuation of the organogenesis. Although data in other groups are still incomplete, a comparison of the A. impalearis table with that of other lizards reveals a great homogeneity of embryonic development in these reptiles, except for the external ornamentation which is specific.

Examination of Cichlid fishes belonging to the genera Oreochromis, Tilapia, Sarotherodon, Hemichromis, Konia, Stomatepia, Pungu, Nanochromis and Chromidotilapia from Cameroon, Senegal and Chad revealed the presence of 19 myxosporidian species belonging to the genera Sphaerospora Thélohan, 1892, Myxobolus Bütschli, 1882 and Henneguya Thélohan, 1882. Two of these species are new: Myxobolus gandiolensis from kidney of Tilapia guineensis and Henneguya sarotherodoni from intestine of Sarotherodon galilaeus. The following previously described species found are: Sphaerospora melenensis, S. tilapiae, Myxobolus agolus, M. beninensis, M. brachysporus, M. camerounensis, M. clarii, M. equatorialis, M. fotoi, M. galilaeus, M. heterosporus, M. homeosporus, M. israelensis, M. kainjiae, M. sarigi, M. tilapiae and M. zillii. These myxosporidia infested numerous organs and tissues. Some of them form cysts.

Preferences for four primary and two secondary alcohols are studied in two geographical races of Drosophila melanogaster. an African population, very sensitive to the alcohol, and a resistant French population. Experimental insects are offspring of mothers submitted to situations of choice between non alcoholic media and others containing doses of studied alcohols. Eggs laid under these conditions are reared on media chosen or avoided by the mother. The adaptation of offspring to tested media is estimated using the following parameters: the number of emergences, the developmental time, the weight and the length of wings. The study reveals a better adaptation of French animals than African ones to alcoholized resources. This marked tolerance of the French population is particularly observed in the case of media with 0.5 % ethanol added. However this beneficial effect of ethanol is not observed with other alcohols. The adaptation of insects to an alcoholized medium is a complex phenomenon that influences the maternal preference. Thus, females who prefer non alcoholic or slightly alcoholized media have, in general, made a choice which conforms to the requirements of larvae. Those that laid on media containing strong doses of a highly poisonous alcohol (such as 2-propanol) seem, even if it is opposite to the requirements of the progeny, to have a tendency to exploit a new medium at the price of a limited development of the offspring.

A protozoan community living in sandy marine sediments in a shallow sublittoral environment was studied in terms of diversity, density and biomass. Different abiotic parameters (granulometry, pH, temperature, dissolved oxygen, redox potential, salinity and conductivity) were recorded, as well as factors relating to nutrients (phosphate, nitrate, nitrite and organic matter). Bacterial biomass was also analyzed. The protozoan species were grouped as follows: ciliates, pigmented flagellates (AFLA), heterotrophic flagellates (HFLA), pigmented dinoflagellates (ADIN), heterotrophic dinoflagellates (HDIN) and sarcodines. Despite the fact that with regard to the relative frequencies of protozoan species, there were statistical differences between the sampling points, no significant differences existed when the protozoan groups were considered throughout the year. In addition, there were no differences with respect to surveys previously carried out in the same and neighbouring areas, and using the protozoan groups mentioned, which shows their stability. The trophic relations between these protozoan groups have been deduced from the data and the statistical results. The annual cycle appeared divided into four stages: herbivorous web (February–April), microbial loop (May–July), microbial web (August–October) and multivorous web (November–January).

The dermal covering of Chondrichtyes is constituted by thousand of odontods, sometimes used as a taxonomic tool in the systematics of this group. Even if the morphological and distribution characteristics of these dermal structures show an important variability among species, the main morphological characteristics can be used in the systematics of adult and sub-adult specimens. The dermal covering of basal Batoids shows important local variations of the same kind as observed within sharks. Moreover, most of the rays show a reduced dermal covering constituted by sharp-crowned and largely spaced denticles, absent in Torpediniformes and some Myliobatiformes. Among the Rajids, study of the dermal covering of different species belonging to the genus Raja shows that a diagnostic character due to morphological variations of the crown can be used. This character, only discovered in some species of the subgenera Raja and Amblyraja, constitutes a systematics character used among Rajidae.