Ecomorphology ofCrassostrea cucullata (Born, 1778) (Ostreidae) in a mangrove creek (Gazi,Kenya)

Variations of shell form and shell length were studied for oysters growing in the mangroves of Gazi Creek, Kenya, and related to different environmental factors.For the study of the form, Fourier analysis was performed on the circumference of 85 oysters. The resulting coefficients were compared among specimens using cluster analysis. The correspondence between this classification and substrate diameter is virtually perfect (only one misclassification out of 85 oysters). For the clusters based on height above chart datum, 9 specimens, all on intermediate height levels, were misclassified. Orientation with respect to tidal current had 13 misclassifications. Mangrove species seemed to influence form only marginally, if at all.In the study of the size ofCrassostrea cucullata, the length of 956 oysters, growing along two transects were measured, and correlated with several environmental factors. Oyster length was not related to substrate diameter or its orientation with respect to the main current. Length was not influenced by density up to a cover of 70%. For densities higher than 70%, there was a fairly strong negative correlation (r ² = 0.634,n = 217). Length was not correlated with height above bottom (base of the tree) for heights lower than 20 cm, while oysters growing closer to the bottom were smaller. The correlation with height above chart datum was negative but very low (r ² = 0.060,n = 957). However, if all measurements of oysters closer than 20 cm to the bottom, and all from a density of more than 70% cover are deleted from the data set, the correlation with height increased dramatically, the slope still being negative (r ² = 0.859,n = 543).     

Solgerites Reeside, 1932 (Cretaceous Ammonoidea) a synonym ofForresteria Reeside, 1932, with a revision ofSolgerites brancoi (Solger, 1904) (Cretaceous Ammonoidea) from Cameroon

A revision of the surviving “Barroisiceras” specimens from Cameroon described by SOLGER (1904) suggests thatBarroisiceras brancoi, type species ofSolgerites REESIDE, 1932, including varietiesmitis andarmatus of SOLGER, andBarroisiceras hoberfellneri alstadenensis SOLGER non SCHLüTER are variants of a single species and thatSolgerites is a synonym ofForresteria (Forresteria) REESIDE, 1932, of whichEboroceras BASSE, 1947 also is a synonym.     

Parasitization of a hydrothermal vent limpet (Lepetodrilidae, Vetigastropoda) by a highly modified copepod (Chitonophilidae, Cyclopoida)

The limpet Lepetodrilus fucensis McLean is very abundant at hydrothermal vents on the Juan de Fuca and Explorer Ridges in the northeast Pacific Ocean. This limpet is parasitized by an undescribed chitonophilid copepod throughout the limpet's range. The parasite copepodite enters the mantle cavity and attaches to the afferent branchial vein. The initial invasive stage is a vermiform endosome within the vein that develops an extensive rootlet system causing an enlargement of the afferent branchial vein. Subsequently, an ectosomal female body grows outside the vein to sizes up to 2 mm in width. Once a dwarf male attaches, egg clusters form and nauplii are released. In over 3000 limpets examined from 30 populations, prevalence averaged about 5% with localized infections in female limpets over 25%. After the establishment of limpet populations at new vents, copepod prevalence increased over the succeeding months to 3 years. Host effects were marked and included castration of both sexes and deterioration in gill condition which affected both food acquisition and the gill symbiont. There was a significantly greater parasite prevalence in larger females which likely modifies the reproductive and competitive success of local host populations.     

The hemiramphid,Oxyporhamphus, is a flyingfish (exocoetidae)

Osteological and myological studies on the caudal complex of flying fishes (Exocoetidae) plusOxyporhamphus (of Hemiramphidae) revealed the following shared derived conditions: 1) neural spines of preural vertebrae broader than haemal spines; 2) spur present on posterior margin of preural vertebra 2;3) upper hypural plates steeply angled; 4) lower hypural plate extending strongly posteriorly; 5) lower hypural plate deeply surrounded by caudal fin rays; 6) flexor ventralis well developed, arising from neural spines; 7) flexor ventralis externus well developed; 8) adductor dorsalis well developed.Oxyporhamphus and exocoetids also share a lower jaw of adults not elongate and the premaxilla with a straight anterior margin. Therefore,Oxyporhamphus is transferred to the Exocoetidae, with which it shares a total of 10 derived conditions.     

Toxorhina (Ceratocheilus) caucasiensis,a new species from the Middle Miocene of Stavropol (northern Caucasus,USSR) (Diptera,Limoniidae)

Middle Miocene limnic deposits from Stavropol contain wings of the limomidToxorhina (Ceratocheilus) caucasiensis n. sp. Recent species of this genus are distributed in tropic regions around the world.     

Scymnodon plunketi (Waite, 1910): a junior synonym of Scymnodon macracanthus (Regan, 1906) (Somniosidae: Elasmobranchii)

The taxonomic status and validity of Scymnodon macracanthus (Regan, 1906) and Scymnodon plunketi (Waite, 1910) are revised in light of new material from the Southern Pacific and Indian Oceans. Despite being historically accepted as distinct taxa, recent studies suggested the possibility that these species could represent a single taxon. Morphometrics, meristics and morphology of dermal denticles show that S. plunketi is indeed a junior synonym of S. macracanthus. Previous distinctive characters proved to be the result of intraspecific variation. S. macracanthus is therefore redescribed including an updated comparative diagnosis for the genus Scymnodon in the family Somniosidae.     

Redescription of a rare flathead,Onigocia grandisquama (Regan, 1908) (Scorpaeniformes: Platycephalidae)

A rare platycephalid,Onigocia grandisquama (Regan), is redescribed in detail from the holotype and an additional specimen collected from the Gulf of Thailand, western Pacific. The species is characterized by the following combination of characters: 11 anal fin rays, 32–34 lateral line scales, anteriormost 3–5 or 3–6 lateral line scales with a distinct spine, 1–2 preocular spines, broad and flat ocular flap, and long head (42.4–44.7% of standard length).     

Bioefficacy of root extracts of a medicinal plant,Withania somnifera (Dunal) against a polyphagous pest,Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae)

Oral administration of root extracts of a medicinal plant, Ashwagandha (Withania somnifera) to last instar larvae of a polyphagous pest, Spodoptera litura resulted into abnormal morphogenesis and the effects comprised mortality, delay in larval-pupal and pupal-adult ecdysis, ecdysial stasis, formation of larval-pupal and pupal-adult intermediates, reduced pupation and formation of abnormal pupae, complete suppression of normal adult emergence and formation of adultoids. These effects are similar to those produced by the administration of JHAs and may be due to interference with the normal hormonal mechanism of moulting and metamorphosis.     

Peptide YY, a new gut hormone (a mini-review)

This report describes our current knowledge of a new gut peptide hormone, peptide YY. The localization, action, and possible mechanisms that control release of peptide YY are described.