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Ecophysiology of dorsal versus ventral cuticle in flattened sawfly larvae.
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Platycampus larvae are highly cryptic leaf feeders characterised by a dorso-ventrally flattened body, the dorsal integument resembling a shield. Dorsal and ventral cuticles from Platycampus luridiventris were compared by histology and gel electrophoresis. By Azan-staining, a red and a blue layer were distinguished in the dorsal cuticle, while the ventral cuticle showed one, almost uniform blue layer, as in both cuticles of control species. The two cuticles from P. luridiventris had similar amounts and sodium dodecyl sulphate-polyacrylamide gel electrophoresis profiles of soluble proteins, but not insoluble proteins. One insoluble protein (MW approximately 41 kDa) was visible as a large band in the ventral cuticle only. It is likely that this protein renders the cuticle elastic, and that the dorsal, red layer is the exocuticle, mainly composed of insoluble proteins. We discuss eco-physiological implications of the exocuticle in insects. Further, data from the literature indicate that the defence strategy in P. luridiventris larvae relies on being visually cryptic towards avian predators and tactically cryptic towards arthropod predators and parasitoids. Crypsis in both senses is favoured by the shield effect, itself based on an abnormally thick dorsal exocuticle. Although the larvae are external feeders, they may be considered as hidden from an ecological perspective.
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A phylogeny and taxonomy of the Thai-Malay Peninsula Bent-toed Geckos of the Cyrtodactylus pulchellus complex (Squamata: Gekkonidae): combined morphological and molecular analyses with descriptions of seven new species
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Cryptic species in Iphisa elegans Gray, 1851 (Squamata: Gymnophthalmidae) revealed by hemipenial morphology and molecular data
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From Amazonia to the Atlantic forest:molecular phylogeny of Phyzelaphryninae frogs reveals unexpected diversity and a striking biogeographic pattern emphasizing conservation challenges
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Low genetic diversity in tepui summit vertebrates
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Reptiles of Venezuela: an updated and commented checklist
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Fruits and seeds from the Tienen Formation at Dormaal, Palaeocene–Eocene transition in eastern Belgium
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Fish otoliths and their relevance to archaeology: an analysis of medieval, post-medieval and recent material of plaice, cod and haddock from the North Sea
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The growth increments were investigated of late medieval, post-medieval and modern otoliths of plaice, cod and haddock from the North Sea. Thin-sectioned otoliths were used to age all the analysed individuals and to reconstruct their growth patterns. In addition, fish lengths of the archaeological specimens were calculated after the relation between otolith width and fish length was established using modern material. The age and fish length distribution, and the growth patterns obtained on the archaeological material allow inferences about fish trade, market strategies and consumption behaviour on producer sites (coastal sites) and consumer sites. Differences in growth patterns were observed between the archaeological and recent populations of the three demersal species analysed which may be related to a change in fishing pressure through time. However, diachronic changes in species distribution, temperature, food availability and selection of catch in function of market strategies may have played a role as well. Age and body size data allow some inferences about the exploited fishing grounds, but the growth patterns are of limited use in this respect.
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An identification key for dermal denticles of Rajidae from the North Sea
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As a result of more systematic fine sieving on archaeological sites, dermal denticles and isolated teeth of rays are now more frequently recovered than before. A detailed description of the teeth is available in the literature, but no comparative study of the morphology of the dermal denticles exists that allows the identification of such elements issued from archaeological sites. A key and illustrations are provided for the identification of the dermal denticles of 10 ray species from the North Sea. In addition, the ray denticles have been analysed from seven medieval and postmedieval sites showing their potential for the interpretation of ichthyo-archaeological assemblages.
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The ancient fish fauna from Asa Koma (Djibouti) and modern osteometric data on 3 Tilapiini and 2 Clarias catfish species
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The fi sh fauna is presented from Asa Koma; a prehistoric site dated around 1800 cal BC and located in Djibouti near Lake Abhé. The site comprises numerous hearths from which the fi sh bones that form the majority of the faunal remains were recovered. Only two fi sh species occur, namely Oreochromis niloticus and Clarias gariepinus, which are also the two major taxa occurring in the saline lake today. The skeletal element distribution and the frequency of charred remains were analysed and, in addition, detailed size reconstructions were carried out. On the basis of modern skeletons from 47 tilapia and 39 Clarias, the metrical relationship between fi sh length and individual bone measurements (32 measuring distances for tilapia and 40 for Clarias) was established with the aid of the “least squares method”. The equations are all listed for future use by other researchers. The fi sh and other fauna do not allow a precise environmental reconstruction, but the large size of the Clarias possibly indicates less saline conditions than today. Using the reconstructed sizes of the fi sh from Asa Koma, modern data on the behaviour of the species, ethnographic and archaeological parallels, and palaeohydrological data, attempts are made to establish the most likely season of fi shing, the possible location of the fi shing grounds, and the fi shing methods that may have been used. Finally, the possible fi sh preparation and fi sh processing methods are discussed.
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