Acta Zoologica最新文献

This is the first study to examine the distribution of a chemokine CXCL14-like peptide in the pituitary and hypothalamus of an avian species, the Japanese quail (Coturnix japonica). We employed immunohistochemical techniques using a specific anti-human CXCL14 antibody. CXCL14-immunoreactive cells were detected in the caudal lobe of the pars distalis. CXCL14-immunoreactive puncta were densely distributed in the external layer and sparsely distributed in the internal layer of the median eminence. CXCL14 staining was absent after pre-absorption of the antibody with recombinant human CXCL14. All CXCL14-immunoreactive cells corresponded to growth hormone (GH)-producing cells in the caudal lobe. In addition, the majority of CXCL14-immunoreactive puncta in the median eminence corresponded to somatostatin-containing fibres. CXCL14 secreted from GH-producing cells and somatostatin-containing fibres may act as an inhibitor of GH release via an autocrine mechanism and neuroendocrine signalling, respectively.

Since the beginning of the 1990s, palaeontologists have been interested in understanding biological processes recorded within the bone microstructure of deinonychosaurian theropods, the group comprising Troodontidae and Dromaeosauridae. Several studies were published on this subject, and the growing database requires the first revision of used terminology and older interpretations. Furthermore, a platform correlating the developmental characters of all investigated taxa is missing. Hence, we lack a perspective to evaluate the potential of deinonychosaurian osteohistology for understanding their evolution and that of their close relatives, including avialans. This study aimed to fill in this gap by offering a comprehensive review of the previous osteohistological investigations published on deinonychosaurians and Archaeopteryx. Four significant evolutionary phenomena are assumed from the investigated deinonychosaurian taxa: (1) it is likely that troodontids evolved general osteohistology closer to basal avialans than to dromaeosaurids, (2) in troodontids, reticular vasculature is correlated to maturation timing, (3) the first growth deceleration occurs later in smaller deinonychosaurs (e.g. Changyuraptor, Sinornithosaurus) than in larger forms (e.g. Buitreraptor), and (4) the growth rate of the deinonychosaurs' hind limbs might be correlated with a specific type of locomotion.

Spinal ganglia and peripheral nerves innervate the regenerating tail and muscles of lizards, which provide new opportunities to probe the mechanisms leading to successful functional recovery following spinal cord injury. The regenerated spinal cord and peripheral nerves were detected using immunohistochemistry in original and regenerating tails of Scincella tsinlingensis. Our results showed that positive PCNA, GFAP and SOX2 cells were observed in the ependymal ducts at 15 and 30 days after the autotomy (dpa), with a small number of immunopositive NSE neurons. GFAP and SOX2 positive cells were primarily localized along the regenerated spinal cord after 45 dpa, and the descending nerve of medulla tissue showed positive NSE. Peripheral axons distributed around the muscle and inside the connective tissue and muscle tissue at 15 dpa. The number of axons decreased after 30 dpa. The peripheral axons was mainly distributed between the connective tissue, muscle group and the muscle and epidermis, presenting a radial distribution centred on the cartilage tube at 120 dpa. MBP myelination labelling of the regenerated tail at 30 dpa revealed that the regenerated axons rapidly myelinated along the rostro-caudal axis. The density of NMJ significantly increased at 120 dpa and 250 dpa. In the second regenerated tails, NMJ density at 250 dpa was still greater than original tails. Overall, these results indicated that neurogenesis was an early event and the ependymal cells were heterogeneous in the regenerated spinal cord of S. tsinlingensis. The regenerated peripheral axons presented a radial distribution centred on the cartilage canal, and the regenerated axons were rapidly myelinated along the rostro-caudal axis. During the process of regeneration, there were a large number of regenerated neuromuscular joints with high density.

Although scorpions have comparatively low regenerative potential, legs and pedipalps are able to regenerate some structures in an often incomplete manner. The most intriguing scorpion appendages are the ventrally located pectines. These organs are equipped with numerous sensilla that scan the substrate for mechanosensory- and chemosensory cues. Due to their ventral position and frequent substrate contact, pectines are vulnerable to traumatic injuries. Pecten malformations have been hypothesized to be the result of incomplete regeneration. To investigate their regeneration capabilities, the pectines of postembryonic stages of Euscorpius italicus (Herbst, 1800) were amputated before the second moult at three different positions. Data on intermoult periods and the number of pectinal teeth were gathered for approximately 2.5 years. The regeneration process on exuviae of up to six moulting events was documented by photographs and confocal laser-scanning microscopy. Regardless of the amputation site, no evidence for regenerative capabilities of pectines in E. italicus could be reported. Thus, incomplete regenerations mentioned in the literature are likely the result of simple wound healing. Depending on habitat complexity, substrate contact time of the pectines seem to differ, which might be interpreted as a trade-off between highest sensory input and the avoidance of traumatic injury of the pectines.

The morphology of the female reproductive system in Cercopis vulnerata, an economically important species, was examined with light and scanning electron microscopy techniques. The female reproductive system of C. vulnerata has two ovaries, each containing 14 telotrophic meroistic ovarioles joined by two lateral oviducts that open in a common oviduct. In this type of ovarioles, the trophocytes within the germarium are transferred to the developing oocytes in the vitellarium via the nutritive cords. The oocytes in the vitellarium have three different development stages: previtello, vitello and choriogenesis. The ovarioles open in the lateral oviduct with a thin canal-shaped pedicel. A pair of lateral oviducts opens distally into the common oviduct. The oviducts are surrounded by a monolayer cubical epithelium with deep folds toward the lumen and a thick muscle layer. A pair of spermatheca and a bursa copulatrix are seen near the common oviduct. Spermatheca has an elongated shape. The bursa copulatrix has an ovoid tube-like structure. No work has been done on the female reproductive system of Cercopidae to date. This study was conducted to fill this gap and forms part of the female reproductive system morphology of this economically important insect.

A group of aquatic Coleoptera specimens was collected from Güvenç Village in the Kahramankazan region of Ankara. Among these specimens was Dryops rufipes (Krynicki, 1832) (Coleoptera: Dryopidae), which is recorded from the Middle Anatolian Region of Turkey for the first time. The egg morphology of D. rufipes is described based on light and scanning electron microscope micrographs. Copulation and oviposition are described.

Analysis of skin development in the Australian lungfish, Neoceratodus forsteri, indicates that keratinocytes form 2 to 3 irregular layers in tadpoles of 2–5 cm in length and are fully stratified (7–12 layers) in juveniles of 16.5–26 cm in length. The epidermis produces mucus and mainly contains intermediate filament keratins of acidic nature but also a minute amount of neutral-basic keratins (pI 7.0–7.3), which is unique among fish. The latter keratins of 60–62 kDa, are generally present in tetrapods but the specific gene structure and amino sequence of acidic, neutral and basic keratins in N. forsteri are presently unknown. No other epidermal proteins are detected although biochemical data suggest the presence of non-keratin proteins, including a basic type (pI 8.0–8.2) of around 32 kDa of molecular weight. The spinulated bony layer of elasmoid scales contains glycoproteins involved in mineralization, such as osteonectin and osteopontin. Also, alkaline phosphatase, involved in calcium precipitation onto the collagen matrix, has been detected in scales of juveniles up to 26 cm in length. The present review concludes that the knowledge of the data derived from epidermal and dermal protein annotation from the recently sequenced genome of this fish species will contribute to address the study on the evolution of tetrapod skin.

Ecological aspects are essential for testing hypotheses about the characteristics, evolutionary processes and behaviour patterns of different taxa. However, for many neotropical lizards, like Gymnodactylus darwinii, such information is scant in the literature. This lizard is endemic to the Atlantic rainforest, occurring from Rio Grande do Norte to São Paulo. Herein, the aspects of trophic ecology, microenvironmental specificity and sexual dimorphism were analysed from 65 collected individuals and 15 sighted individuals in two conservation units: Camucim and Tapacurá, located in São Lourenço da Mata, north-eastern region of Brazil. The data found classify G. darwinii as a saxicolous lizard, with a preference for rocky outcrops, without sexual dimorphism. According to its trophic ecology, the species is considered a generalist and sit–wait forager. Arthropods, especially Orthoptera and Araneae, dominate the lizard's diet. Neither of these aspects differed between seasons. The present study also shows the importance of the domain conservation, with the aim to provide resources for many vertebrates, especially endemic species.

At the beginning of the Middle Pleistocene (MIS 21, 800,000 BP), three distinct hyenas remained to appear in Europe with the spotted hyena (Crocuta), brown hyena (Parahyaena) and striped hyena (Hyaena). Each developed in monophyletic lineages, whereas rare brown hyena Parahyaena brunnea mosbachensis (Geib, 1915) and striped hyena Hyaena hyaena prisca De Serres, Dubreuil and Jeanjean, (1828) did not change in their dentition morphology much to their modern forms. Those warm period extinct hyenas did not migrate from Africa over the Rhine Graben migratory channel to Central Europe after the late Mid-Pleistocene Holsteinian Interglacial (MIS 9). The spotted hyenas took over the niche of European hyenas with their appearance in warm and cold periods. Those used more and more cave entrances as dens between Spain and Siberia. Their more rapid dental change coevolved from the largest “giant hyena” Crocuta brevirostris Boule, (1893) (Early Pleistocene, MIS 40-20), over Crocuta intermedia De Serres, Dubreuil and Jeanjean, 1828 (Early Mid-Pleistocene, MIS 19-12), C. praespelaea Schütt, 1971 (Early Mid-Pleistocene, MIS 11-6), to Crocuta crocuta spelaea (Goldfuss, 1823) (Early Mid-Pleistocene, MIS 5-3), which is genetically a subspecies to Modern African extant Crocuta crocuta crocuta Erxleben, 1777 (MIS 2-1). Spotted hyenas developed a perfect thick-skin cutter M1 by elongation and bone crusher conical P4 teeth. This adaptation to their main thick-skin big game guilt: elephants, rhinos and hippos.

Larvae of Melolonthinae (white grubs) are usually considered as serious pests for some of them attacking plant roots and causing great losses of agriculture and forestry. However, not all the white grubs are pest species. In this study, the adult Apogonia cupreoviridis were observed to feed on gramineous grasses and fallen ginkgo leaves, while their larvae were frequently collected in the lawn. The larvae were reared in the laboratory and observed using scanning electron microscopy. The larvae have the plegmatia expanded in the middle; distal antennomere with an apical process bearing one bifurcated sensilla and nine sensilla basiconica on the apex; the palidia are V-shaped and each palidium bearing five to nine pali. The V-shaped palidia are found in the known larvae of Diplotaxini, as to genera Apogonia and Liogenys.