Temperature is a critical factor limiting various aspects of the biology of ectotherms. In addition to environmental factors, coloration and body size are two physical properties that influence ectotherms' body temperature (T_b). I compared the influences of these properties on thermal aspects of the two morphs of the color-dimorphic snake (E. quadrivirgata) under experimental conditions. First, I fitted T_b data during heating to the von Bertalanffy equation, but considered parameter values of the equilibrium temperature obtained to be biologically meaningless. Alternatively, I limited the data for comparison of the morphs to T_b≤35°C, which was the T_b at which snakes began to move vigorously in the experiment. The rate of T_b increase was significantly greater in the melanistic morph than in the striped morph. Heating rate was negatively correlated with body size in both morphs. The interaction of body size and heating rate did not significantly differ between the two morphs. The possibility of linkage, due to thermal advantage, between small body size and the prevalence of melanism in the population studied is briefly discussed. Rapid increase of T_b is biologically advantageous because snakes with such ability would be released from various time and environmental constraints associated with thermoregulation under particular environmental conditions.

Variations in body size of the suspension-feeding lancelet Branchiostoma belcheri were examined from April 2001 to December 2001 at different water depths of 10–80 m. The lancelets were abundantly collected (220 indiv./dredge) at water depth of 10 m. The maximum size, ranging from 36.8 to 50.4 mm BL, decreased with increasing water depth. However, the minimum size of 7.4–7.8 mm BL, which corresponds to settling size, did not different with water depth. From seasonal changes in the length-frequency histograms, five cohorts were observed at every water depth. The lancelets grew to 44 mm BL at water depths of 10–20 m and to 34 mm BL at water depth of 80 m with four years of life span. Developmental stages of the gonads at an age of two years showed that no individuals had undeveloped gonads at water depth of 10 m, but 82% of them did at water depth of 80 m. The analysis of the stepwise multiple regressions of monthly growth rate on environmental variables showed that chlorophyll a was the best explanatory variable and showed a significant positive correlation with the growth of 1–2 years age groups. These results suggested that variations in the body length were mainly fluctuated by phytoplankton supply.

Influences of photoperiod on plasma melatonin profiles and effects of melatonin administration on long-day-induced smoltification in masu salmon (Oncorhynchus masou) were investigated in order to reveal the roles of melatonin in the regulation of smoltification in salmonids. Under light-dark (LD) cycles, plasma melatonin levels exhibited daily variation, with higher values during the dark phase than during the light phase. The duration of nocturnal elevation under short photoperiod (LD 8:16) was longer than that under long photoperiod (LD 16:8). Melatonin feeding (0.01, 0.1 and 1 mg/kg body weight) elevated plasma levels of melatonin in a dose-dependent manner for at least 7 h but not for 24 h. When masu salmon reared under short photoperiod were exposed to long photoperiod (LD 16:8) and fed melatonin (1 mg/kg body weight) 7 hours before the onset of darkness, a significantly smaller proportion of smolts appeared in the melatonin-fed group after 32 days than in the control group. However, after 59 days of the treatment, there was no difference in the proportion of smolts between the control and melatonin-treated groups. Thus, melatonin feeding mimicked the effects of short photoperiod, which delays but does not completely suppress smoltification. These results indicate that the day length is transduced into changes in the duration of nocturnal elevation in plasma melatonin levels, and that artificial modification of the plasma melatonin pattern possibly delays the physiological processes of smoltification induced by long-day photoperiodic treatment.

Most colonial corals vary intraspecifically in growth forms, and the diversity in branching morphology is especially striking. While the effects of environmental factors on growth forms have been studied, the genetic control of coral branching patterns has received little attention. The discovery of ontogenetic changes in the capacity to originate branching would set the stage for studies of how branch formation is genetically controlled. During experiments investigating contact reactions in the coral Pocillopora damicornis, we observed that young colonies derived from settled planulae and colonies regenerated from adult branch tips assumed different growth forms. Young colonies formed at least one branch from the central region of the colony, while colonies regenerated from adult branch tips (3–5 mm long) did not form branches during the 9-month observation period. This pattern was invariable, regardless of the types and outcomes of the contact experiments or the orientation of the branch tips. However, some fragments taken from 1- or 2-year-old colonies formed branches. This suggests that the rate of branch formation in P. damicornis colonies decreases with age. These findings will facilitate investigations of the mechanism of coral branch formation at the molecular level.

A phylogenetic hypothesis of the subgenus Nialoe (s. lat.) of genus Pterostichus is proposed based on a cladistic analysis of seventeen morphological characters. Through comparative studies of the sclerites on the endophallus of male genitalia, it became apparent that the arrangement of these sclerites reflects seven different origins. The results show that Nialoe (s. lat.) is monophyletic and composed of four clades, while some traditional taxa are para- or polyphyletic, and are defined only by symplesiomorphies. Pterostichus (Nialoe) mosaicus sp. nov., which is indispensable for tracing the homology of sclerites in this subgenus, is described.

Pterostichus (Nialoe) asymmetricus Bates and its allies are revised based on the membranous parts of their genitalia. Four new taxa, P. (N.) ovaliphallus sp. nov., P. (N.) fujimurai ibukiyamanus ssp. nov., P. (N.) shotaroi kiimontanus ssp. nov., and P. (N.) basilobatus sp. nov. are described. A cladistic analysis based on 31 morphological characters reveals that Daisenilaoe (s. str.) Nakane and Straneo is included as one clade within Nialoe (s. str.). The speciation and dispersal process of this species group are also discussed.

Hynobius naevius, distributed on western Honshu, Shikoku, and Kyushu Islands of Japan, includes two genetically distinct groups (Groups A and B) that have never been delimited morphologically. Using specimens from the entire species range, we investigated the possibility of distinguishing these groups morphologically. Multivariate analyses of morphometric characters resulted in recognition of two groups that corresponded well to the two genetic groups. One (Group A) was characterized by larger body, compressed tail, shallower vomerine tooth series, bluish- or reddish-purple ground color, and pale-white lateral markings. In contrast, another (Group B) was characterized by smaller body, cylindrical tail, longer vomerine tooth series, reddish-brown ground color, and white lateral markings. Group A was composed of populations from the Chugoku District of Honshu and northern Kyushu, and could not be divided into subgroups, while Group B encompassed populations from the Chubu and Kinki Districts of Honshu, Shikoku and Kyushu, and was subdivided into three local subgroups that are geographically separated by marine straits. Morphometric differentiation in Group A is presumed to have been less affected by genetic factors than by other factors, such as ecological relationships with other, coexisting species. Differentiation in Group B is assumed to have been enhanced not only by genetic but also by climatological factors.

Cetaceans are well adapted to their hyperosmotic environment by properly developed osmoregulatory ability. A question here is how they regulate water and mineral balances in marine habitats. In the present study, we determined blood and urine levels of various chemicals involved in osmoregulation, compared them with those in artiodactyls, and characterized the values in the whales. Blood and urine samples obtained from baleen whales of common minke (Balaenoptera acutorostrata), sei (B. borealis), and Bryde's whales (B. brydei), and toothed whales of sperm whales (Physeter macrocephalus) were analyzed for osmolality, major electrolytes, urea, steroid hormones and glucose. The urine osmolality and Na concentrations in the cetaceans were much higher than those in the cattle. Furthermore, the cetaceans had 5 to 11-fold urea in plasma than the cattle, and 2 to 4-fold urea in urine. There were no significant difference in the plasma concentrations of corticosteroids between the cetaceans and the cattle. The present results indicate that the osmoregulatory parameters seem to be not affected by the reproductive stage and sex steroid hormones. The concentrations of urea in plasma and urine of the baleen whales were higher than those of the sperm whales, indicating a possibility that their osmoregulatory mechanisms may be correlated to their feeding habits. The present results suggest that cetaceans have unique osmoregulatory mechanisms by which they excrete strongly hypertonic urine to maintain fluid homeostasis in marine habitats.

The silken girdles of pupae of the swallowtail butterfly Atrophaneura alcinous show black and white color diphenism. Field observations revealed that all pupae observed on non-food plants and the leaves and stems of the larval food plant Aristolochia debilis were classified as a silken girdle of a black type, while a large portion of pupae pupating on the twigs and trunks of cherry trees in close proximity to A. debilis were classified as a silken girdle of a black type. Additionally, all pupae observed on the surfaces of artificial objects in areas where there are no surrounding plants or trees were classified as a silken girdle of a white type. We demonstrated the effect of day length and the texture, light, plant odor and humidity of pupation sites on the coloration of the silken girdle in A. alcinous. Regardless of long-day or short-day day length conditions, light conditions of constant light or dark, or the presence of a plant odor of A. debilis as environmental cues, all larvae placed at over 80% relative humidity (R.H.) developed into pupae with a silken girdle of a black type. However, all larvae developed into pupae with a silken girdle of a white type when R.H. was below 75%. Furthermore, when pupae with a silken girdle of a white type were transferred to conditions of 90% R.H. within 24 hr of pupation, the white color of the silken girdle changed into a black type within 24 hr of the transfer. The present data suggest that the induction of a black coloration of the silken girdle in A. alcinous requires a R.H. of approximately 80% or more as an environmental factor.

A new species group, the sinensis group, is established within the genus Dichaetophora, based on a phylogenetic analysis of 37 adult morphological characters from 26 drosophilid species, including ten known species of Dichaetophora; four newly described species (Di. abnormis, Di. hainanensis, Di. bicornis, and Di. sinensis spp. nov. from China); and some representatives of related genera (Drosophila, Hirtodrosophila, and Scaptomyza).

The monotypic Japanese spider genus Metimorpha Strand, 1906 is known only from the juvenile holotype of M. tullia Bösenberg and Strand, 1906. The genus is not a tetragnathid as currently catalogued, nor a nephilid as tentatively suggested in the original description. Metimorpha is transferred to Araneidae, but the name is proposed as a nomen dubium.

A new species, Attheyella namkungi sp. nov., is described from Gosu cave at Danyang, Chungcheongbuk-do, South Korea. This species bears a superficial resemblance to A. coreana Miura, 1969 in having a 2-segmented mandibular palp with only four smooth apical setae, and in the armature formulae of the antennary exopod and thoracic legs. However the new species is clearly distinguishable by the non-sexually dimorphic caudal rami, two long plumose setae and a short seta on leg 6, and the absence of the setular row at the inner lateral margin of each caudal ramus. The new species is characterized from other congeners by having two adjacent inner spines on female leg 3 endopod-2, the caudal ramus twice as long as its width, absence of a barbed apophysis on male leg 3 endopod-2, and the seta number of legs 5 and 6. A key to the Korean species of the genus Attheyella is provided.

A new semiterrestrial tardigrade, Insuetifurca austronipponica, is described from Kakeroma Island, Kagoshima Prefecture, southern Japan. This is the third species known for the genus. It is distinguished from I. fujiensis primarily by a narrower buccopharyngeal tube and a longer pharyngeal tube, and from I. arrowsmithi primarily by a microplacoid clearly shorter than the macroplacoids.