Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact helpdesk@bioone.org with any questions.
A literature-based taxonomic catalogue of the nemertean species (Phylum Nemertea) reported from Japanese waters is provided, listing 19 families, 45 genera, and 120 species as valid. Applications of the following species names to forms previously recorded from Japanese waters are regarded as uncertain: Amphiporus cervicalis, Amphiporus depressus, Amphiporus lactifloreus, Cephalothrix filiformis, Cephalothrix linearis, Cerebratulus fuscus, Lineus vegetus, Lineus bilineatus, Lineus gesserensis, Lineus grubei, Lineus longifissus, Lineus mcintoshii, Nipponnemertes pulchra, Oerstedia venusta, Prostoma graecense, and Prostoma grande. The identities of the taxa referred to by the following four nominal species require clarification through future investigations: Cosmocephala japonica, Dicelis rubra, Dichilus obscurus, and Nareda serpentina. The nominal species established from Japanese waters are tabulated. In addition, a brief history of taxonomic research on Japanese nemerteans is reviewed.
A study was undertaken to determine the rate of population expansion of an ischnoceran Phthiraptera, Goniocotes gallinae (infesting the domestic fowl, Gallus gallus domesticus), on the basis of in vitro and in vivo studies. Data obtained from in vitro rearing were utilized to construct the life history of the louse. The values of the gross reproductive rate (12.49 female eggs/female), net reproductive rate (8.31 female eggs/female), mean length of generation (36.91 days), precise generation time (35.65 days), finite rate of increase (1.06 female/days), and intrinsic rate of natural increase (0.059) of G. gallinae were determined. However, doubling-time values recorded during in vivo studies (14 days) was comparatively higher than those during in vitro rearing (11.73 days).
Unilaterally cercus-ablated crickets, Gryllus bimaculatus, were reared in an apparatus that induced walking artificially. In the crickets that experienced different distances of enforced walking per day, the directionality of escape was investigated before and 1, 4, 7, 10, 13, and 16 days after the ablation of the cercus. The crickets that walked a longer distance per day showed a quicker and a higher degree of compensational recovery of the escape direction than the crickets that walked a shorter distance per day, even after walking the same distance. Thus, the time course and amount of compensational recovery from cercal ablation depend on when crickets experience walking during the recovery period. During the recovery period, unilaterally cercus-ablated crickets were subjected to walking at different times to determine the most effective period in which walking affects the compensational recovery of escape direction. The compensational recovery of the escape direction occurred only in crickets experiencing walking in early periods after the ablation. In particular, walking experienced 2–6 days after the ablation was most effective for the compensational recovery. On the other hand, no compensational recovery occurred in crickets experiencing walking in later periods after the ablation. These results suggest that there is a sensitive or critical period in which walking affects the compensational recovery of escape direction.
The slaty (Dctslt) mutation is known to reduce the activity of dopachrome tautomerase in melanocytes and to reduce the melanin content in the skin, hairs, and eyes. The slaty gene is known to be important for maximizing melanin deposition in melanosomes. However, it was not known whether the slaty mutation affects the morphology of melanosomes. Moreover, it was unknown whether melanosome development is modulated by melanogenic factors. In this study, the characteristics of melanosomes of slaty melanocytes in serum-free primary culture were investigated in detail under the electron microscope. In slaty melanocytes, melanosome maturation was blocked at stage III, and numerous spherical melanosomes with globular depositions of pigment in addition to elliptical melanosomes were observed. L-tyrosine (Tyr), the starting material of melanin synthesis, is known to stimulate melanin synthesis. To clarify whether L-Tyr restores the reduced production of melanin, L-Tyr was added to the culture medium and tested for its melanogenic effect. L-Tyr greatly increased the number and percentage of mature stage IV melanosomes. Moreover, L-Tyr increased elliptical melanosomes, but decreased spherical melanosomes. These results suggest that the slaty mutation inhibits the development of elliptical stage IV melanosomes, and that L-Tyr restores the development of elliptical stage IV melanosomes. L-Tyr seems to restore both the morphology and maturation of melanosomes affected by the slaty mutation.
Interspecific hybridization has been proposed as a possible explanation for the incredible diversity seen in reef-dwelling corals, but until now little proof of such hybridization in other reef-dwelling anthozoans has been reported. Without further observation of hybridization, the question of such a phenomenon being widespread in Anthozoa remains. Here we have examined the mitochondrial cytochrome oxidase I gene (COI) and the nuclear internal transcribed spacer of ribosomal DNA (ITS-rDNA) from three species of the mass-spawning, encrusting anemone genus Zoanthus (Z. sansibaricus, Z. kuroshio, Z. gigantus) to investigate possible hybridization. The three species coexist at two of three sampling locations in southern Japan. Zoanthus spp. ITS-rDNA region spacers (ITS-1 and ITS-2) were shown to have very high rates of divergence. At locations where all three species co-existed, several of our sampled Z. sansibaricus individuals (with identical “sansi” COI sequences) possessed two very divergent (i.e., species-level difference) ITS-rDNA alleles, the expected “sansi” allele and the divergent “B” allele. Additionally, two Z. sansibaricus individuals possessed only “B” alleles despite having “sansi” COI sequences. These results indicate that Z. sansibaricus has possibly experienced interspecific hybridization at least once with a Zoanthus partner possessing the “B” allele, and that these resulting hybrids may also sexually reproduce, demonstrating potential hybridization occurring in the order Zoantharia (Hexacorallia).
In order to elucidate the genetic relationships and reproductive-isolation mechanisms among the Fejervarya limnocharis complex from Indonesia and other Asian countries, allozyme analyses and crossing experiments were carried out using 208 individuals from 21 localities in eight Asian countries. The allozyme analyses revealed that 17 enzymes examined were controlled by genes at 27 loci, and that 7.9 phenotypes were produced by 5.2 alleles on average. The two species recognized in F. limnocharis sensu lato from Southeast Asia (i.e., F. limnocharis sensu stricto and F. iskandari) were found to occur sympatrically at three localities (Bogor, Cianjur and Malingping), all on Java, Indonesia. Fejervaya iskandari was dominant at each of these localities and showed substantial geographic genetic variation. Laboratory-produced hybrids between F. limnocharis and F. iskandari from Java became underdeveloped and died at the tadpole stage, suggesting that these species are completely isolated by hybrid inviability. Hybrids between topotypic F. limnocharis and the Malaysian and Japanese conspecific populations developed normally to metamorphosis. Likewise, hybrids between topotypic F. iskandari and the Thailand and Bangladesh conspecific populations also showed normal viability throughout larval development. The present allozyme analyses and crossing experiments strongly suggested the presence of two distinct forms, the large type and the small type, in the F. limnocharis complex from Asia, and further subdivision of the large type into the F. limnocharis assemblage and the F. iskandari assemblage. The small type was found in samples from India, Thailand, Bangladesh and Sri Lanka, and included at least three different species. The sample from Pilok, Thailand, was considered to represent an undescribed species.
Eggs, hatchlings, and adult loggerhead turtles, and incubation durations of clutches, were measured on three Turkish beaches (Dalyan, Fethiye and Göksu Delta), and some physical features of nests were compared. These features were not statistically different among the beaches, except for nest depth and distance to the high water mark. There was a positive relationship between hatchling mass and egg size. The carapace length of hatchlings was correlated with both egg diameter and incubation duration. The duration of asynchronous emergence of hatchlings on Fethiye beach was slightly longer than on the other two beaches, and the size of hatchlings decreased as asynchronous emergence proceeded. Of the hatchlings that emerged first, those that died were significantly smaller in SCL and mass than those that lived. These results suggest that smaller hatchlings may not be vigorous enough to emerge earlier from nests, and that they may be less fit.
Prevalences of two phthirapteran species (an ischnoceran, Brueelia amandavae, and an amblyceran, Myrsidea amandava) on 130 Red Avadavats (Amandava amandava) were 36.2 and 20.8% in the district of Rampur, India, from September to December 2004. Sample mean abundances of the two species were 3.43 and 1.53, respectively. The frequency distribution patterns of both species were aggregated. The observed distribution conformed to the expected distribution of the negative binomial model, but only in the case of M. amandava. Adults dominated over nymphs in the overall adult-to-nymph ratio. Sex ratios of both species were skewed (female biased).
Most studies on egg incubation in reptiles have relied on constant temperature incubation in the laboratory rather than on simulations of thermal regimes in natural nests. The thermal effects on embryos in constant-temperature studies often do not realistically reflect what occurs in nature. Recent studies have increasingly recognized the importance of simulating natural nest temperatures rather than applying constant-temperature regimes. We incubated Bungarus multicintus eggs under three constant and one fluctuating-temperature regimes to evaluate the effects of constant versus fluctuating incubation temperatures on hatching success and hatchling phenotypes. Hatching success did not differ among the four treatments, and incubation temperature did not affect the sexual phenotype of hatchlings. Incubation length decreased as incubation temperature increased, but eggs incubated at fluctuating temperatures did not differ from eggs incubated at constant temperatures with approximately the same mean in incubation length. Of the hatchling phenotypes examined, residual yolk, fat bodies and locomotor performance were more likely affected by incubation temperature. The maximal locomotor speed was fastest in the fluctuating-temperature and 30°C treatments and slowest in the 24°C treatment, with the 27°C treatment in between. The maximal locomotor length was longest in the fluctuating-temperature treatment and shortest in the 24°C and 27°C treatments, with the 30°C treatment in between. Our results show that fluctuating incubation temperatures do not influence hatching success and hatchling size and morphology any differently than constant temperatures with approximately the same mean, but have a positive effect on locomotor performance of hatchlings.
Ghrelin is a gut-brain peptide synthesized mainly in the oxyntic mucosal cells of the stomach, and has potent growth hormone (GH)-releasing and orexigenic activities. Recently, two forms of ghrelin, ghrelin-C8 and -C10, were identified in the Mozambique tilapia (Oreochromis mossambicus). The present study describes in vitro and in vivo effects of these endogenous ghrelins on the GH/insulin-like growth factor-I (IGF-I) axis. Ghrelin-C8 (100 nM) stimulated GH release from primary cultures of pituitary cells after 4 and 8 h of incubation, whereas no effect was seen on prolactin (PRL) release. Stimulatory effects of ghrelin-C8 and -C10 (100 nM) on GH release during 6 h of incubation were blocked by pre-incubation with GHS receptor antagonist, [D-Lys3]-GHRP-6 (10 μM). Intraperitoneal injection of ghrelin-C8 (1 ng/g body weight) and -C10 (0.1 and 1 ng/g body weight) significantly increased plasma GH levels after 5 h. Significant increases were observed also in hepatic expression of IGF-I and GH receptor (GHR) mRNA following injections of both forms of ghrelin (0.1 and 1 ng/g body weight), although there was no effect on plasma levels of IGF-I. In the next experiment, both forms of ghrelin (1 ng/g body weight) significantly increased plasma IGF-I levels 10 h after the injection. No significant effect of either ghrelin was observed on plasma PRL levels. Both forms of GHS receptor (GHSR-1a and -1b) were found in the pituitary, clearly indicating that tilapia ghrelins stimulate primarily GH release through the GHS receptor. Stimulation of hepatic expression of IGF-I and GHR suggests metabolic roles of ghrelin in tilapia.
We constructed a genomic DNA library for Lipotes vexillifer (L. vexillifer), the Baiji or Yangtze River dolphin, one of the most endangered mammals in the world. The library consists of 149,000 BAC clones, with an average insert size of 83 kb, representing approximately 3.4 haploid genome equivalents. PCR amplification of four known L. vexillifer genes yielded two to four positive clones each. To demonstrate the utility of this library, we isolated and sequenced the L. vexillifer alpha lactalbumin gene, which is a gene specific to mammals and one which has been widely used as molecular tool in phylogenetic analysis. We also end-sequenced 20 randomly selected clones, resulting in the identification of at least five new L. vexillifer genes, five SSR loci, and one SINE locus. These results suggest that this library is a valuable resource for candidate gene cloning, physical mapping, and genome sequencing of this important and threatened species.
The objective of the present study was to develop and validate a simple, sensitive, quick and economic enzyme immunoassay (EIA) for estradiol-17β (E2) in mithun (Bos frontalis) plasma on microtiter plates using a second-antibody coating technique and hormone-horseradish peroxidase as a label. For the assay, the wells of microtiter plates were coated with affinity-purified goat anti-rabbit IgG that binds the hormone-specific antibody. One milliliter of mithun plasma was extracted using benzene and 50 μl of 300 μl volume reconstituted with assay buffer was run in the assay along with standards ranging from 0.10–100 pg/well prepared in assay buffer. The sensitivity of the assay was 0.72 pg/ml. The intra- and inter-assay coefficients of variation were below 10%, and the extraction efficiency was >93%. Linearity of recovery of the added hormone concentrations was recorded. The assay developed was further validated biologically by estimating the hormone concentrations in six female and five male mithun calves, 12 cyclic mithuns for the entire reproductive cycle, and four pregnant mithun cows. The EIA developed can estimate low concentrations of E2 (2.2–5.2 pg/ml) in growing calves as well as very high concentrations of the hormone during pregnancy (E2=85.6–143.5 pg/ml). Apart from being non-radioactive, the assay developed has several advantages over conventional radioimmunoassays: it is more sensitive, less labor intensive, simpler to perform, and less time consuming. In conclusion, the EIA procedure described herein is sufficiently reliable, economic, safe, quick and sensitive to estimate the hormone at all physiological levels in bovine plasma.
The Oriental ‘fly-like’ leafhoppers of the Doda group are reviewed and a key is given for their separation. Two new genera and two new species are described: Pseudododa gen. n. (with type species P. orientalis sp. n.) and Aculescutellaris gen. n. (with type species A. hirtellus sp. n.). The variation within the former species is documented and illustrated, and the special mineral uptake behavior (‘mud-puddling’) of this genus and other Cicadellidae is reviewed.
This article is only available to subscribers. It is not available for individual sale.
Access to the requested content is limited to institutions that have
purchased or subscribe to this BioOne eBook Collection. You are receiving
this notice because your organization may not have this eBook access.*
*Shibboleth/Open Athens users-please
sign in
to access your institution's subscriptions.
Additional information about institution subscriptions can be foundhere