13. Lake Saloio (Nazaré, western Portugal)

The possible impact of altitude and the related microclimatic conditions on the total production of fruiting branches, inflorescences, flowers and pollen grains of olive trees Olea europaea was analysed. A total of 90 Picual cultivar trees, the most extensive olive cultivar in the Iberian Peninsula, were studied for a three-year period (2007–2009). The study shows that production of flowers and pollen grains in a cultivar of the olive tree varies according to the microclimate. Our study also indicates that the olive trees frequently can have up to half a million flowers per tree. Moreover, the total flower production differs between years and study areas. In the Picual cultivar, the average production of pollen grains per anther is usually more than 60?000 grains. The total production of pollen per tree is around 72?000 million on average. The most favourable microclimatic conditions for reproduction in olive trees are found in years and olive growing areas with low temperature and high precipitation records during the months prior to flowering of the olive trees. We hypothesise that olive trees tend to increase their pollen production rate as altitude increases, which can be interpreted as a reproductive strategy to ensure fertilisation.     

Rhodymenia delicatula P.J.L. Dangeard (Rhodophyta,Rhodymeniales) en Méditerranée

Abstract

Presence of Rhodymenia delicatula P.J.L. Dangeard in the Mediterranean. - The presence of Rhodymenia delicatula P.J.L. Dangeard (Rhodophyta, Rhodymeniales) in the southern Thyrrhenian sea is reported. Both cystocarpic and tetrasporic individuals have been collected. Anatomical features of the reproductive structures, as well as the position of these on the thallus allowed the identification of this species formerly known for the Atlantic coasts of Morocco and British Isles.     

Création du genre Californiella N.gen. (Rhodophycophyta) et révision du genre DasyporellaStolley, 1893 (Dasycladales)

The genus Dasyporella was created by Stolley in 1893. Later, two different species were assigned to this genus under the same specific name Dasyporella norvegica. One of them was misinterpreted by Johnson & Konishi (1959) which introduced a confusion in the genus definition. The revision of the genus Dasyporella was therefore necessary and the study of new specimens belonging to the misinterpreted species have led to the creation of a new genus: Californiella. This new genus clarifies the concept of Dasyporella with the reinstatement of its original definition.     

Ultrastructure des photorécepteurs de Lineus ruber (O. F. Müller) (Hétéronémertes Lineidae)

Résumé Lors de la régénération traumatique des yeux de Lineus ruber la différenciation biochimique des nouvelles cellules pigmentaires est séquentielle. On assiste à l'apparition successive des chaînes enzymatiques nécéssaires à la biosynthèse de porphyrine et de mélanine.Les études ultrastructurale et autoradiographique à haute résolution de ces phénomènes — montrent que la mélanisation s'opère au niveau d'organites cellulaires spécialisés (prémélanosomes, mélanosomes). La porphyrinogénèse se développe dans des vacuoles et organites d'origine golgienne qui participent également à la mélanogénèse.

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Ultrastructure of photoreceptors in Lineus ruber (O. F. Müller)

Summary In Lineus ruber the biochemical differentiation of the new pigmentary cells is sequential during the reparative regeneration of the eyes. The enzymatic pathways for porphyrin and melanin biosynthesis appear successively.Ultrastructural and high resolution radioautography studies, show that melanization occurs in specialized organelles called premelanosomes, melanosomes and melanin granules. Prophyrogenesis occurs in Golgi vesicles which are also involved in melanogenesis.

     

Loreleiella nov. gen., nouvel éodévonariidé(Chonetacea,Brachiopoda) du Dévonien

The detailed morphological analysis of the dorsal interior of Chonetes arcuatus Hall, 1857, typespecies of the genus Eodevonaria (North American Lower Devonian), compared with those of the European species classically assigned to this genus, allows the erection of a new genus for the European eodevonariids. The phylogenetic relations of Loreleiella nov. gen. and its paleobiogeographic implication are discussed.     

Ultrastructure des photorécepteurs de Lineus ruber (O. F. Müller) (Hétéronémertes Lineïdae)

Summary The eyes of the Nemertean worm Lineus ruber are situated on the dorsal face of the animal in two lateral bands in front of the cerebral ganglia. There are 6 or 8 ocelli per animal enclosed in the cephalic parenchyme. They consist of a pigmented eyecup in which 50 photoreceptor cells are present. The photoreceptrice cells have:dendritic processes which are full of mitochondria, neurotubules, vacuoles and only one axial filament;a pericaryon with rough endoplasmic reticulum, a Golgi apparatus and few mitochondria.

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Résumé Les yeux de la Némerte marine Lineus ruber sont situés sur la face dorsale de l'animal, en deux rangées parallèles à l'avant des ganglions cérébroïdes. On en dénombre 6 à 8 localisés dans le parenchyme céphalique. Ils consistent en une cupule pigmentaire entourant une cinquantaine de cellules visuelles qui rejoignent les centres nerveux supérieurs. Pour les cellules photoréceptrices on distingue:un processus dendritique riche en mitochondries, neurotubules, vacuoles et possédant un axe médian;un corps cellulaire où l'on trouve du réticulum endoplasmique rugueux, un appareil de Golgi développé mais peu de mitochondries.

     

Pleomorphism inScenedesmus quadricauda (Turp) Bréb. (Chlorophyceae)

A clone ofScenedesmus quadricauda, isolated from Tjeukemeer, exhibits a high degree of morphological variation in synchronized cultures. Cells are synchronized by light-dark cycles. During the photoperiod they build up the capacity to divide. First division into 2- and 4-celled coenobia is induced, then during the second half of the photoperiod the induction of division into 8 unicells takes place. Division itself and the subsequent liberation of daughter cells occur in the dark period.By giving a definite photoperiod the formation of either coenobia or unicellular stages is determined. The formation of both coenobia and unicells is followed using a light microscope. In both cases only the pattern of cytokinesis is similar. After cytokinesis the unicells become ovoid in shape and form two spines at each pole. They are released from the parental wall as separate cells and show remarkable similarity to theChodatella-like cells described by SWALE (1967) and FOTT (1968). The coenobial cells elongate, adhere to one another and each of the two outmost cells forms two spines (SMITH, 1914).     

Sur le développement abortif de certains embryons deLineus ruber (O.F. Müller) (Hétéronémertes)

Sommaire ChezLineus ruber on observe deux types de développement dans la même ponte: un développement normal et un développement abortif. Les ufs qui donnent des embryons normaux émettent deux globules polaires, les ufs qui donnent des embryons anormaux n'émettent qu'un globule polaire. Ils ne sont pas fécondés mais commencent à se diviser et arrivent tardivement au stade 16–32 blastomères, puis la segmentation s'arrête. On suggère l'existence d'une parthénogénèse abortive. Les facteurs du déclenchement du processus du développement abortif sont discutés.

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Abnormal development of some embryos of lineus ruber (O. F. Müller) (Heteronemertine)

Summary One can observe in the case ofLineus ruber, two types of development in the same egg string, a normal one and an abortive one. The eggs which give the normal embryos, give two polar bodies while the eggs which give the abnormal embryos, issue one polar body only, they are not fertilized but start to divide and belatedly reach the stade of 16–32 blastomeres.The existence of an abortive parthehogenesis is suggested and the mechanism of abnormal development is discussed.

     

Révision du genre Pycnomorphus Thomson, 1864. Systématique et phylogénie (Coleoptera : Lamiinae,Acanthoderini)

Le genre Pycnomorphus Thomson est révisé et quatre espèces nouvelles sont décrites: Pycnomorphus guyanensis n. sp., P. pradosiae n. sp.et P. sarryi n. sp. de Guyane, et P. batesi n. sp. du Nicaragua. Un genre nouveau Pycnomorphidiellus n. gen. est créé pour une nouvelle espèce de Guyane, P. polyphagus n. sp. Une analyse cladistique et une clef d’identification des espèces complètent ce travail.