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The impact of naval sonar on beaked whales is of increasing concern. In recent years the presence of gas and fat embolism consistent with decompression sickness (DCS) has been reported through postmortem analyses on beaked whales that stranded in connection with naval sonar exercises. In the present study, we use basic principles of diving physiology to model nitrogen tension and bubble growth in several tissue compartments during normal div ng behavior and for several hypothetical dive profiles to assess the risk of DCS. Assuming that normal diving does not cause nitrogen tensions in excess of those shown to be safe for odontocetes, the modeling indicates that repetitive shallow dives, perhaps as a consequence of an extended avoidance reaction to sonar sound, can indeed pose a risk for DCS and that this risk should increase with the duration of the response. If the model is correct, then limiting the duration of sonar exposure to minimize the duration of any avoidance reaction therefore has the potential to reduce the risk of DCS.
The avifauna of the island of Flores and its satellite islands from Komodo to Alor is reviewed, combining historical data with recent observations. Recent surveys have added substantially to the data base, especially of the resident forest species, and endangered and endemic taxa, as well as adding a number of migrant and maritime species to the island list. Of particular interest are the rare forest endemics Wallace's Hanging-parrot Loriculus flosculus, the almost unknown Flores Scopsowl Otus alfredi, Flores Monarch Monarcha sacerdotum and Flores Crow Corvus florensis. An appeal is made for further surveys over the eastern part of the island and the eastern island chain.
È stata effettuata una revisione sistematica sulle specie del genere Genista in Italia. L'indagine ha permesso di accertare la posizione tassonomica delle diverse entità che rappresentano il genere nel territorio italiano. In questa prima nota sono riferiti i risultati emersi dallo studio delle entità di sezioni a prevalente distribuzione in opposte zone del bacino del Mediterraneo e precisamente Erinacoides Spach del Mediterraneo occidentale ed Ephedrospartum Spach, Aureospartum sect. nova del Mediterraneo centrale. La sezione Erinacoides é rappresentata da G. salzmanii DC. in Sardegna e in Corsica, G. pichisermolliana sp. nov. in Sardegna, G. aspalathoides Lam. in Sicilia, Pantelleria, Africa settentrionale, G. desoleana Valso in Liguria, Toscana, Elba, Corsica e Sardegna, G. arbusensis Vals., G. sulcitana Valso e G. toluensis Valso in Sardegna. La sezione Aureospartum (sect. nova) comprende solo l'endemica sardo-sicula G. aetnensis (Raf.) DC. e l'Ephedrospartum racchiude G. ephedroides DC. presente in Sardegna, G. thyrrena Valso nell'arcipelago ponziano, G. gasparrini in Sicilia e G. cilentina Vals. in Campania e in Sicilia.
1. The migration of the spotted mackerel, Pneumatophorus tapeinacephalus distributing in the coastal sea of Japan was investigated in relation to the geographical distribution of the fishing grounds, seasonal change of fishing condition. sea conditions and fork length. Secondarily, some anatomical and histological observations were carried out on spotted mackerels caught in the coastal sea area around Kagoshima and its vicinity to clarify the sex differentiation and the seasonal cycle of the gonads. 2. Spotted mackerels are distributed throughout a wide sea area stretching from north of Formosa to the south of Japan Sea. including the Pacific coastal sea from Kyushu to Chiba Prefecture. The northern limit of the distribution area is assumed to be the sea areas off San-in and Chosi. 3. The schools of adult fish make a feeding migration to the circumference of Saishu Island and to the sea area off Ashizuri cape in summer. and these schools make a spawning migration toward the sea area around the Osumi Islands and the southern area of the East China Sea in winter. 4. In winter some schools of adult fish remain living in the sea area south of the Izu Islands. These schools belong to a group isolated incompletely from that of the East China Sea. as some of them are those which came from the East China Sea. 5. The larvae grow while they are being brought by the sea current or tide current. When they have reached 50~60mm. in total length. they aggregate in schools and approach the coast. In spring they swim in the coastal nursery grounds. 6. From summer to autumn, the schools of the young fish make a feeding migration to the sea off San-in and to the eastern coastal sea of Chiba Prefecture. In winter. they make a seasonal migration to the coastal sea of South Kyushu, the East China Sea and the southern sea area of the Izu Islands. 7. The range of vertical distribution of the larvae is supposed to be the layer from the surface to 40m. in depth. The vertical distribution of the adult fish is chiefly in the layer, 40-70m. in depth, during the period from late autumn to early spring. It becomes shallower in late spring and summer, the depth being about 20-40m. 8. The ranges of water temperature and salinity in the sea where the adult fish schools are distributed are 17.0-26.0°C and 34.0~34.8%0. respectively. 9. The spawning takes place during the period from the end of January to June in the southern part of the East China Sea and the sea areas around the Osumi Islands, off Ashizuri Cape and around the Izu Islands. These spawning grounds are sea areas where a comparatively rapid current is running towards a land shelf. 10. The ranges of the optimum water temperatures and salinities for the spawning are assumed to be 17-23°C and 34.0-34.8 0/00, respectively. 11. The primordial germ cells seem to migrate to the gonad by amoeboid movement from other places than the gonad. 12. The early indifferent gonad is very slender and suspended with a mesogonium, in the coelom. It is composed of peritoneal epithelium, stroma cells and primordial germ cells. 13. The formation of the gonocoel begins as a longitudinal depression on the surface of the gonad, facing the mesentery. This depression takes place in the gonad of the fish, about 60mm. in fork length, prior to the sex differentiation. 14. The sex differentiation occurs directly without a phase of a juvenile hermaphrodite. 15. The gonad in which the gonocoel is greatly enlarged becomes an ovary, while that in which the gonocoel is left narrow becomes a testis. 16. In the early ovary the layer containing oogonia is surrounded with stroma cells. The surface of the ovary is covered with cuboidal epithelium. 17. In the ovary of the fish, 100-130mm. in fork length, the wall of the ovocoel forms small protuberances, which become the lobes of the ovary. The oocytes are situated in these lobes. The yolk formation begins in the oocytes, 15.....,20.a in diameter, 18. The maturing process of eggs is clasified into the following 7 stages; the chromatin nucleolus, the peripheral nucleolus, the yolk vesicle, the early yolk globule, the late yolk globule, the migrating nucleus and the matured stage. Ovarian eggs at the migrating nucleus stage and the matured stage are observed in the fish, more than 300mm. in fork length. 19. The surface of the early testis is covered with peritoneal epithelium. The interior is filled up with the multiplied stroma cells and the spermatogonia scattered among them. In the testis of a somewhat later stage, a lot of branches are stretched out of the testocoel. Some of the spermatogonia are arranged directly beneath the peritoneal epithelium and the others are buried deep in the testis. The testis lacks a layer of stroma cells under the peritoneal epithelium. 20. In the testis of young male fish the spermatogonia increase in number and surround the small branches of testocoel; they form seminiferous tubules. The testocoel and its large branches become the rete apparatus constructed of collecting ducts. The maturation division appears in the testes of the fish more than 280mm. in fork length. 21. The sex ratio of the young fish is approximately 1 : 1. The ratio between the gonad length and the fork length shows an exponential increase. The gonads of adult fish are enlarged about 9-13 % of the original length during the spawning season. 22. During the months from July to November the oocytes in the ovaries of adult female :fish are at the chromatin nucleolus stage and the peripheral nucleolus stage. During the same season there are only spermatogonia in the testes of adult male fish. The gonads of adult fish begin to increase in size in December and become the largest in March and April. The increase in size of the ovary is chiefly due to the enlargement of ova on account of yolk deposition. The increase in size of the testis is due to accumulation of spermatozoa. 23. A few oogonia can be seen m the ovanes of adult female fish during and immediately after spawning. Numerous spermatogonia appear along the inner walls of the seminiferous tubules late in the spawning season.
The siliceous claystone and chert lithologic units of the Triassic-Jurassic chert-clastic sequence are well exposed in the Inuyama, Mt. Kinkazan and Hisuikyo areas of the southeastern Mino Terrane. Twenty-one continuous sections from those areas were investigated in order to establish comprehensive radiolarian biozones and clarify the successive lithologic changes through the Triassic and lowest Jurassic. Twenty new radiolarian zones are established; the lowest two are assemblage zones and the others are defined by the first or last occurrence of index taxa. The definitions are as follows in chronological order: TR 0, Follicucullus Assemblage Zone (early Spathian or older); TR 1, Parentactinia nakatsugawaensis Assemblage Zone (late Spathian); TR 2A, Eptingium nakasekoi Lowest-occurrence Zone (early Anisian); TR 2B, Triassocampe coronata group Lowest-occurrence Zone (early Anisian); TR 2C, Triassocampe deweveri Lowest-occurrence Zone (late Anisian); TR 3A, Spine A2 (possiblly derived from Oertlispongus inaequispinosus) Lowest occurrence Zone (late Anisian) ; TR 3B, Yeharaia elegans group Lowest-occurrence Zone (early Ladinian); TR 4A, Muelleritortis cochleata Lowest-occurrence Zone (late Ladinian); TR 4B, Spongoserrula dehli Lowest-occurrence Zone (late Ladinian to early Carnian); TR 5A, Capnuchosphaera Lowest-occurrence Zone (early Carnian); TR 5B, Poulpus carcharus sp. nov. Lowest-occurrence Zone (early to late Carnian); TR 6A, Capnodoce- Trialatus Concurrentrange Zone (late Carnian to early Norian), TR 6B, Trialatus robustus-Lysemelas olbia gen. et sp. nov. Partial-range Zone (early Norian); TR 7, Lysemelas olbia gen. et sp. nov. Lowest-occurrence Zone (early to late Norian); TR 8A: Praemesosaturnalis multidentatus group Lowest-occurrence Zone (late Norian); TR 8B: Praemesosaturnalis pseudokahleri sp. nov. Lowest-occurrence Zone (late Norian) ; TR 8C: Skirt F (possiblly derived from Haeckelicyrtium takemurai) Lowest-occurrence Zone (late Norian to early Rhaetian); TR 8D: Haeckelicyrtium breviora sp. nov. Taxon-range Zone (early to late Rhaetian) ; JR OA: Haeckelicyrtium breviora sp. nov.-Bipedis horiae sp. nov. Partial-range Zone (Hettangian); and JR OB: Bipedis horiae sp. nov. Lowest-occurrence Zone (Hettangian/Sinemurian) . These zones are correlated to previousy established radiolarian assemblages and zones in Japan and other regions. Age assignment of the zones is also discussed on the basis of the correlation and other available chronological data. The original stratigraphic succession of the Triassic in the studied area, which ranges in age from Early Triassic to Early Jurassic, is more than 100 m in thickness and can be reconstructed in detail. The succession is subdivided into seven units based on lithologic features. Each unit was probably accumulated under a particular sedimentary condition, thus successive changes of paleoceanographic environments during Triassic time can be traced continuously. Nine new genera including Ayrtonius, Blonzella, Braginella, Bulbocampe, Enoplocampe, Lysenzelas, Parvibrachiale, Spongoxystris and Veles, and 47 new species are described herein. A comprehensive list of identified taxa is presented.
Resume 1) The egg of Squilla oratoria DE HAAN is centrolecithal and undergoes partial cleavages resulting in rudimentary primary yolk pyramids. 2) The germinal disk is first represented by a pair of optic lobes and a ventral plate, which are afterward connected by paired, lateral ectoderm thickenings to form a V-shape. The V is then transformed into an O by the appearance of a transverse band between the optic lobes of both sides. 3) A small blastopore is formed. Of the mesendoderm cells derived from the blastopore by cell immigrations, those attached to the lower surface of the lateral ectoderm thickenings are differentiated into a U-shaped, naupliar mesoderm band. This inesoderm band joins the preante:mulary mesoderm derived from the optic lobe, and grows into a complete ring conforming to the shape of the germinal disk. 4) The extra-blastoporic immigrants consist of a preantennulary mesoderm, mesodermal yolk cells and a part of the naupliar mesoderm. The greater part of the preantennulary mesoderm cells disintegrate sooner or later, without forming any distinct structure. The mesodermal yolk cells also degenerate after taking part in the dissolution of the deutoplasm. A discussion as regards the mutual relationship between these elements, with the conclusion that the formation of the preantennulary mesoderm represents the initial step of the extra-blastoporic cell sinking from the whole egg surface, is included. 5) The endodermal elements consist of a compact cell mass differentiated from the posterior part of the mesendoderm layer and the endodermal yolk cells immigrated from the blastopore. The yolk cells, after migrating through the most peripheral part of the yolk, scatter all over its surface. The endoderm plate is nothing but a mass of yolk cells. which remain without scattering. 6) Eight mesoteloblasts derived from the blastoporic lip are attached to the inner surface of the thoracico-abdominal process, making four groups. The ectoteloblasts are differentiated from the ordinary blastoderm cells in a later stage than the mesoteloblasts. In the final condition they consist of 21 cells forming a complete ring around the thoracico-abdominal process. 7) Both the ectoderm and the mesoderm are derived from the teloblasts in all of the post-naupliar segments.· The dorsal ectoderm, however, is non-teloblastic in only a few anterior segments. Differentiation of segments proceeds from the front toward the back. 8) The telson mesoderm is formed by the cells sunk from the telson ectoderm which is derived from the peri-blastoporic ectoderm . 9) The anus is the remnant of the blastopore. In accordance with the change of the caudal furca, the anus is displaced from the dorsal side of the telson to the ventral border between this and the last abdominal segment. 10) There is a distinct nauplius stage. Of the meta-naupliar segments, those from the m:txillula to the second maxilliped are laid on the germinal disk, the following segments together forming a thoracico-abdominal process. Two maxiliiped segments, however, are later separated from the cephalon with the development of the carapace fold, and join the trunk segments. Externally, six abdominal segments are formed. 11) The ganglionic cells are proliferated from the neuroblasts occupying the most superficial part of the centra1 nervous system. The giant ganglionic cells arise from the ordinary ganglionic cells and not directly from neuroblasts. The development of the cerebrum is described. The tritocerebra of both sides are conne~ted by a transverse nerve-fibre bundle behind the stomodaeum. The ganglia of the segments from the mandible to the second maxilliped first exhibit a typical ladder-like shape. Of these ganglia, the anterior three constitute a sub-resophageal ganglion by more or less complete fusion, while the posterior two are transferred from the cephalon to the thoracico-abdomimil process with the constriction of the segments. The inter-ganglionic cell groups take part in the constriction of the consecutive segments. The seventh abdominal ganglion is clearly indicated by the presence of such a cell group as well as of a pair of nerve fibre masses. 12) The development of the compound eye is traced. The ganglion opticum is derived from the ectoderm of the optic lobe lateral to the protocerebrum; it is not an outgrowth of the cerebrum. 13) The ganglion visceralum is differentiated from the anterior wall of the stomodaeum. 14) A median dorsal organ is formed. In close connection with the activity of this organ, the embryo undergoes one ecdysis. 15) The mid-gut epithelium is formed by the gradual expansion of the anterior and posterior endoderm plates over the yolk sac. These plates, however, extend only on the ventral side of the yolk sac before hatching. The posterior plate is produced by the concentration of the scattered yolk cells toward the periphery of the. plate differentiated from the mesendoderm, while the anterior plate is formed by yolk cells alone. 16) The greater part of the intestine develops from the outgrowth of the posterior endoderm epithelium, the proctodaeum occupying only the rectum. 17) The posterior liver lobes are produced from the posterior endoderm plate as a pair of blind tubes and extend as far backward as the telson. The anterior liver lobes and the lateral mid-gut cceca are rather incompletely developed, being ~eparated by shallow superficial grooves of the yolk sac. These two pairs of diverticula are only partially covered by the endoderm epithelium, and develop into more or less distinct coeca during larval life. They later seem to be completely absorbed again by the mid-gut. 18) The product of each division of the mesoteloblast is equivalent to one mesodermal-segment. The mesoderm of the seventh abdominal segment is derived from the posteriorly situated daughter cell produced by the last division of the teloblast. In' accordance with the grouping of teloblasts, the trunk mesoderm is separated into two ventral and two dorsal bands. Each band is further separated into segmentally arranged blocks, the somites. The ccelom develops in no stage and in no segment. 19) The dorsal mesoderm gives rise to the extensor and the oblique muscles of the trunk, the anterior and posterior limb muscles, as well as to the mesodermal inclusion of the limb. The -ventral mesoderm grows into the flexor. The connective tissue investing the intestine -and the liver lobes are principally constructed from the dorsal mesoderm. The germ cell does not appear until hatching. A brief account is also given of the fate of the naupliar mesoderm. 20) The heart wall and the pericardial floor are morphologically one unit. They arise from the dorsal mesoderm as a pair of membranes stretching between it and the intestine. The dilated and elongated parts of the heart are formed by the subsequent union of these paired rudiments. 21) The anterior dorsal vessel has a two-fold origin; it is formed by the fusion of an anterior rudiment extending backward from the rostrum and a posterior one developing as a tubular outgrowth of the heart. The former is derived from the rearrangement of mesenchymatous cells which migrated from the anterior end of the naupliar mesoderm. 22) By the time of hatching, two pairs of lateral vessels are formed as hollow linear thickenings of the pericardial floor in front and behind the dilated part of the heart. 23) The antennal gland remains rudimentary without acquiring any intercellular lumen. The maxillar gland is not laid until hatching. The labral and anal glands are derived from the peristomodaeal and the telson mesoderm respectively. 23) Comparisons are made bewteen Squilla and other orders of Malacostraca as regards the salient points of the embryonic development. These have led to the conclusion that the Stomatopoda are most closely related in their embryonic development to Nebaliacea, and further that Stomatopoda represent a rather primitive group separated from the main stem of Malacostraca very early, only next in order to Nebaliacea.