Système Sétifère des Maxillipèdes des Gonodactyloidea (Crustacea, Stomatopoda)

Analysis of the setal system was conducted on the maxillipeds of Gonodactyloidea, which includes the smashers, a functional group of stomatopods. Generally, the homogeneity of the setal system is demonstrated in stomatopods. However, examination of maxillipeds of Gonodactyloidea reveals that some setal types are systematic characters at levels of families or species. The smashers group has a very homogeneous setal system in three families: Gonodactylidae, Odontodactylidae and Protosquillidae. The setal analysis of maxillipeds confirms the functional role of these appendages. Like other morphological characters, the setal system of stomatopods has co-evolved with behavioral patterns in both groups: spearers and smashers.     

Organisation spatiale des fibres de collagène de la plaque basale des écailles des Téléostéens

Spatial organization of collagenous fibrils in the basal plate of elasmoid scales has been studied in 36 species among 24 teleost families which include the whole order. Angle measurements of the various fibrillary directions were performed on fracture surfaces in frozen scales observed with the scanning electron microscope. The organization of the basal plate is arrayed in three basic patterns. The most remarkable one, found in the more "primitive" families, is a double twisted plywood with a left-handed rotation of the fibrillary directions. The remaining two are an orthogonal plywood, more or less regular, and an "intermediate" plywood, both found among the more "advanced" families. However, an orthogonal plywood is also observed in some "primitive" families, for example in Clupeidae and Salmonidae. We tentatively interpret the left-handed double twisted plywood of the lower teleosteans and of Amiidae as a synapomorphy in relation to the primitive condition of an actinopterygian lineage. On the other hand, within the teleosts, we would consider that the double twisted plywood is a plesiomorphic condition and that the orthogonal plywood is an apomorphy among the "advanced" teleosts families.     

Nature des roches et aires d’approvisionnement en matière première des industries lithiques archaïques des premiers habitants de l’Europe. Exploitation des territoires

The archaic lithic industries of Barranco León and Fuente Nueva sites in Orce in Andalusia and the stone tools of the Vallonnet french site was studied by petroarcheological analyses and reveal the sources exploited by the hominids. The localisation of these sources give data to define the territory exploited. These three examples provide the opportunity to assess the raw material selectivity, the behaviour and the territory occupation system of the first inhabitants of Europe. These lithic industries are composed by local raw material collected very close to the site or even on the site. These sources were probably an important argument on choosing the occupation site.     

Phylogenèse des Phoronida

Phylogenese of Phoronida. Lophophorata and the Archimerata concept The main phylogenetic characteristics of Phoronida and other Lophophorates are discussed: 1. Archimeric segmentation of the body; 2. Egg cleavage of radial (or biradial) type, coeloblastula and gastrulation by invagination (emboly); 3. Mesoderm formation by a derived enteroccelous method (primitive stage of enteroc? ly); 4. Bringing of the anus anteriorly to lie rocoelous method (primitive stage of enterocoely); 4. Bringing of the anus anteriorly to lie sence of a true lophophore; 6. Larva not of trochophoral type, but actinotroch related to Tornaria-Dipleurula; 7. Nervous system basi-epithelial with primitive neurulation in Phoronopsis, without any orthogons; 8. Adult nervous ganglion neo-formed, not issuing from the apicale plate; in Phoronida this ganglion is located in the prosome and not in the mesosome; 9. Lack of cephalization. All these characteristics are closely related to that of the primitive phyla of the Chordata assemblage. The only exception is the presence of protonephridia with solenocytes in actinotroch, but such organs are also described in Cephalochordata. The Lophophorata (Phoronida, Brachiopoda, Bryozoa) are undoubtedly a primitive group on the Chordata trend and the Phoronida appear to be the most phylogenetically evolved phylum of this group with predominating position. The validity of placing the Lophophorata within the Echinoderm-Hemichordata assemblage is demonstrated. The term Archic?lomata appears not suitable and its substitution by Archimerata, assemblage at the base of the Chordata, is here proposed. The Archimerata concept brings together the Lophophorata, Echinodermata and Hemidiordata and is considered as a phylogenetic stage and a natural systematic unit.     

Écologie des Théidées

The Recent thecideid brachiopod Lacazella mediterranea (Risso), studied in the Mediterranean and on the Great Bahama Bank, shows a depth range of 20–150 m (optimum 50–95 m), determined by the need of subdued light. A hard substratum is essential for the cementing of the shell. Brachiopods of the genera Crania. Argyrotheca , and Megathiris belong to the same ecological niche - more or less dependence on light and substratum results in a differentiation of the species in biocoenoses as well and taphocoenoses. Several Mesozoic species are studied in coral, bryozoan, poriferan, and rudist environments. Species like Thecidea papillata (Schlotheim) and Danella recurvirostris (Defrance) seem to have acquired a free life, independent of the substratum, and others, like Praelacazella baltoviensis Barczyk stood fairly intense light in shallow water. Diptych thecideids and megathyridids occurred in bryozoan and coral environments.     

Biosynthèse des acides gras polyinsaturés des glycérolipides de la feuille d'olivier

The patterns of incorporation of [l-¹⁴C]-acetate into the glycerolipid fatty acids of leaves of olive plants ( Olea europea L. cv. Chétoui) suggested a specific pathway for a-linolenic acid biosynthesis. The results confirmed the involvement of phosphati-dylcholine in galactolipid metabolism, and seemed to exclude the role of that mole-cule as a substrate for desaturation of oleate to linoleate. The two oleate desaturation steps seemed to occur rapidly on the diacylgalactosylglycerol molecule for biosynthesis of galactolipid linolenate. In addition, the results indicated a slow sequen-tial desaturation of oleate to linolenate via linoleate in the phospholipid molecules (phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol).     

Influence des caractéristiques des glumelles sur la résistance variétale du riz aux insectes des stocks

Des relations sont recherchées entre les caractéristiques des grains de 58 variétés de riz paddy et leur sensibilité aux quatre principaux ravageurs primaires des stocks: Sitophilus oryzae, Sitophilus zeamais, Rhyzoperta dominica et Sitotroga cerealella. L'étude confirme la prépondérance de l'herméticité des glumelles comme facteur de résistance, et établit que les cassures mécaniques des enveloppes sont des voies de pénétration plus régulières que le défaut de coaptation entre lemma et palea. L'égrenage se révèle être un facteur de sensibilité à S. cerealella aussi déterminant que le défaut de fermeture des glumelles, car lié d'une part à la dureté du pédoncule par lequel les larves de cet insecte peuvent pénétrer, d'autre part au taux de casse des enveloppes provoqué par le battage plus ou moins intense qu'il nécéssite. S'agissant de riz non décortiqué, les caractéristiques des enveloppes expliquent pour une très large part la variabilité de la résistance aux insectes étudiés, dont le développement n'est que faiblement influencé par les caractéristiques propres du grain, tels le format ou la teneur en eau.     

L’utilisation des reliefs pariétaux dans la réalisation des signes au Paléolithique supérieur

For a long time, the images of the Upper Paleolithic were represented in a way that emphasized their aesthetic qualities and ignored the specific characteristics of their natural supports. It is more damageable as the architecture of the decorated caves plays a real part, at different levels, in the elaboration of the parietal devices. As omnipresent elements of these devices, the signs play a determining part in this architecture. Analysing the links between the signs and their direct supports brings to light the various ways in which parietal devices can be used and also the integration and research for the volumes and frame. A study led inside the caves on a sample of 692 signs, distributed in the franco-cantabric paleolithic space, makes apparent the variety of the graphic choices left to the artists standing in front of the wall.     

Influence des conditions expérimentales sur le taux respiratoire des copépodes planctoniques

Measurements of oxygen consumption were carried out on two planktonic copepods, Temora stylifera Dana and Centropages typicus Kröyer under two experimental conditions, namely, degree of confinement and length of time spent in the laboratory. The effect of population density was studied for concentrations between 0.1 animal/ml to 2 animals/ml; the highest rate of respiration was observed in both species for a concentration of 0.5 animal/ml. Concentrations higher (1 or 2 animals/ml) and lower one (0.2 to 0.4 animal/ml) caused a decrease in the respiratory rate. Single animals have respiratory rates similar to those found with a concentration of 0.5 animal/ml. The observed effect of population densities did not depend on the absolute experimental volumes.