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Considerations of the alimentary canal, mesodermal reproductive organs, and ventral nervous system and brain are provided. The treatise is based on studies of 301 species, representing 99 genera, 11 subfamilies, and two cleroid families. A comparative morphology summary is provided. Morphological variations of the stomodaeum, ventriculus, malpighian tubules, confi guration of the spermathecal capsule, shape of the bursa copulatrix, male accessory glands, and testes provide taxonomically useful characteristics. Provided are 252 illustrations. A new name, Katachaetosoma, nom. nov., is proposed to replace the preoccupied name Chaetosoma Dejean (Insecta: Coleoptera: Cerambycidae).
Jirds (genus Meriones) are a diverse group of rodents, with a wide distribution range in Iran. Sundevall’s jird (Meriones crassus Sundevall, 1842) is one such species that shows a disjunct distribution, found on the Iranian Plateau and Western Zagros Mountains. Morphological differences observed between these two populations, however, lack quantitative support. Morphological differences between geographical populations of Meriones crassus were analysed and compared with those of the sympatric M. libycus. Similarities in the cranial morphology of these species were found, e.g. in a relatively large and inflated bulla. A two-dimensional geometric morphometric analysis was done on the skull of 275 M. crassus and 220 M. libycus from more than 70 different localities in their distribution range. Results confirm cranial differences between specimens of M. crassus from the Western Zagros and those from Africa and Arabia, mainly at the level of the relative size of the tympanic bulla, that were significantly correlated with the annual rainfall and elevation. Moreover, the study supports the hypothesis that the Western Zagros specimens are both a geographically and phenotypically distinct group compared to the other Iranian M. crassus specimens, suggesting that the former might be a distinct species.
The taxonomy of the family Desmodoridae (Nematoda: Desmodorida) is partially revised based on morphology. The diagnoses of the Desmodoridae and the subfamilies Desmodorinae and Spiriniinae are emended to accommodate re-analyzed morphological features. Eight known species are redescribed and the implication of the new findings for the taxonomy of the group is discussed. Amphispira and Metadesmodora are confirmed as genera inquirendae. Alaimonema and Sigmophoranema, and their corresponding type species, are proposed as inquirendae due to poor descriptions of the type material. The other three species of Sigmophoranema are transferred to the genus Onyx because they bear the diagnostic features of this group: spear-like dorsal tooth and s-shape precloacal supplements. Echinodesmodora, Paradesmodora and Stygodesmodora are transferred to the Spiriniinae based on the absence of a head capsule and on the amphidial fovea being surrounded by cuticle striation. Paradesmodora toreutes is transferred to the genus Acanthopharyngoides as A. toreutes comb. nov. The genus Onepunema does not fit in the family Desmodoridae because of diorchic males; thus, it is regarded as taxon incertae sedis.
Lists of valid genera for the two subfamilies are provided. A dichotomic key for the identification of the 14 genera within the Spiriinae is provided.
Debate exists regarding the number of species of the moon jellyfish (genus Aurelia), a common member of the planktonic community of the coastal shelf seas around the world. Three Aurelia congeners (A. aurita, A. labiata and A. limbata) are currently considered to exist but recent genetic analyses suggested that this is an oversimplification. We analyzed the morphological characteristics of scyphistomae, morphological characteristics of ephyrae and differences in the time span of the strobilation process of Aurelia congeners from 17, 7 and 6 different source populations, respectively, of known species. Morphological characteristics of scyphistomae were similar among the 17 populations but those of ephyrae, such as the shape and form of lappets, were effective discriminators in the 6 cases examined. We recommend identifying species based on differences in 1) the morphological characteristics of scyphistomae and ephyrae (and not only medusae), 2) the genetics of individuals, and 3) the geographical occurrence of the population. This study adds to the growing body of knowledge on scyphozoan scyphistomae and ephyrae, stages of the metagenic life cycle of scyphozoans that have received relatively little study compared to medusae.
A recent paper on the phylogenetic relationships of species within the cephalopod family Mastigoteuthidae meant great progress in stabilizing the classification of the family. The authors, however, left the generic placement of Mastigoteuthis pyrodes unresolved. This problem is corrected here by placing this species in a new monotypic genus, Mastigotragus, based on unique structures of the photophores and the funnel/mantle locking apparatus.
A hybrid form of tilapia was introduced into Port Sulphur, Louisiana and was subsequently managed by treatment with rotenone and stocking of native predatory fishes. Measurements of tilapia from before this management event were compared to measurements of tilapia in the two years after the treatment. Post-management tilapia were consistently deeper in body and had greater weight per unit length (condition) when compared to pre-management fish. Procrustes generalized least squares data supported this by consistently finding post-management tilapia to be consistently deeper in body and head shape than pre-management fish. Although this could indicate the effectiveness of stocking native predators, several other factors, including two cold winters, seasonal effects, and less competition, may have contributed to this result.
The morphology of presynaptic specializations can vary greatly ranging from classical single-release-site boutons in the central nervous system to boutons of various sizes harboring multiple vesicle release sites. Multi-release-site boutons can be found in several neural contexts, for example at the neuromuscular junction (NMJ) of body wall muscles of Drosophila larvae. These NMJs are built by two motor neurons forming two types of glutamatergic multi-release-site boutons with two typical diameters. However, it is unknown why these distinct nerve terminal configurations are used on the same postsynaptic muscle fiber. To systematically dissect the biophysical properties of these boutons we developed a full three-dimensional model of such boutons, their release sites and transmitter-harboring vesicles and analyzed the local vesicle dynamics of various configurations during stimulation. Here we show that the rate of transmission of a bouton is primarily limited by diffusion-based vesicle movements and that the probability of vesicle release and the size of a bouton affect bouton-performance in distinct temporal domains allowing for an optimal transmission of the neural signals at different time scales. A comparison of our in silico simulations with in vivo recordings of the natural motor pattern of both neurons revealed that the bouton properties resemble a well-tuned cooperation of the parameters release probability and bouton size, enabling a reliable transmission of the prevailing firing-pattern at diffusion-limited boutons. Our findings indicate that the prevailing firing-pattern of a neuron may determine the physiological and morphological parameters required for its synaptic terminals.
Three fossil leafhopper inclusions from Eocene Baltic amber, representing three new extinct genera and species, are described and illustrated. Eomegophthalmus lithuaniensis gen. et sp. nov. is tentatively placed in Megophthalminae, although it may represent the stem group from which Megophthalminae, Ulopinae, and Membracidae arose. Xestocephalites balticus gen. et sp. nov. and Brevaphrodella nigra gen. et sp. nov. are placed in Aphrodinae: Xestocephalini based on the structure of the head, leg chaetotaxy, and male genital capsule. These new genera and species represent the oldest known representatives of their respective subfamilies and the latter is the oldest known brachypterous adult leafhopper.