Animals rely mainly on olfaction to locate and track food sources. However, mammals that have evolved to live partially or fully underwater are unable to use traditional olfaction in the foraging process. These animals have subsequently developed alternative underwater foraging techniques. Cetaceans (e.g. dolphins) live exclusively underwater, and most utilize a highly developed sonar system for navigation and tracking of prey. Pinnipeds (e.g. seals) live on land, but forage underwater. These animals' highly sensitive whiskers allow them to locate food sources. Sirenians (e.g. manatees), the only herbivorous aquatic mammals, also use highly developed whiskers during the grazing process. The semiaquatic mammals Condylura cristata (star-nosed mole) and Sortex palustris (water shrew) have developed the ability to sniff and detect semiochemicals underwater, a discovery that contradicts prior views on the evolutionary relationship between olfaction and aquatic adaptation. The current review details the anatomy of the olfactory systems of these mammals that live and/or forage underwater, and the adaptations they use to follow prey and forage underwater.

We found two patterns of parasitic mating behaviors by male in Japanese medaka, Oryzias latipes, in the spawning by one female and two males in the aquarium condition. In the first type of parasitic mating behavior, the unpaired male would rush toward the closely adhering female and paired male, and simultaneously perform emission behavior with close adhesion to the female (simultaneous emission). The second type of parasitic mating behavior was that the unpaired male would rush toward the female with spawned eggs hanging down from the genital pore several seconds after pair-spawning, perform emission behavior with close adhesion to the female without any prespawning behavior (post-spawn emission). The frequencies of “simultaneous emission” and “postspawn emission” were 20 (19.6%) and 18 cases (17.7%), respectively, in 102 trials, and the average reproductive successes about 41% and 20%, respectively. The reproductive success of simultaneous emission was not correlated with the timing and duration of spawning behaviors of the paired/ unpaired male, while the reproductive success of post-spawn emission significantly decreased as the length of time during which the paired male adhered to female increased. Observations of two consecutive spawning behaviors using same combination of two males revealed that paired males always tend to become paired males. However, the role of both males was occasionally reversed, indicating flexibility in mating tactics.

The western Pacific lancelet, once recognized as a monospecies, Branchiostoma belcheri, is a frequently used model in evolutionary and developmental studies, and researchers usually collect samples from the field without consideration of species identification and genetic divergence. However, recent studies found divergence of the lancelets from different localities and divided this monospecies into two separate species (S. belcheri and B. japonicum). To further estimate the genetic diversity of lancelet populations and the cause of their formation, we sampled 70 individuals from four major distribution areas along the coast of China, using both mitochondrial DNA and microsatellite markers in this investigation. Our results demonstrate that the two species possess extremely high genetic diversity at both mtDNA sequence level (h approaches 1.0) and microsatellite loci (He is above 0.8). Further demographic analysis reveals that the lancelets B. japonicum and B. belcheri underwent a recent historical population expansion at approximately 117,000 and 73,000 years ago respectively. Analyses on the population genetic structure revealed weak differentiation among different local populations. No evident differentiation was found among different local populations of the same species using mtDNA sequence data, but certain divergences among them were identified based on the microsatellite data. We suggest that discontinuous habitats may be responsible for the phylogeographic structure of the lancelets along China coasts.

The common lizard, Zootoca vivipara (Lichtenstein, 1823), shows high variation in life histories and morphology across its range, which comprises almost the entire Palearctic region. However, this variation is not congruent with the species phylogeny. This suggests an important role of the environment in shaping the variation in morphology and life histories of this species. As most data on life histories originate from only a small number of populations and do not cover the species' geographic range and phylogenetic diversity, to fill a gap and provide more information for future comparative studies we investigated reproduction and morphology in two montane populations from Slovakia, central Europe. This region is characterized by taxonomic and phylogenetic diversity and both montane and lowland ecological forms of the common lizard occur here. The common lizards from the Slovak populations are sexually dimorphic, with females having larger body and abdomen lengths and males having larger heads and longer legs. Female common lizards start to reproduce at a relatively large size compared to most other populations. This is consistent with a relatively short activity season, which has been shown to be the main factor driving variation in body size in the common lizard. Clutch size was also relatively high and positively correlated with body size, abdomen size and head size. One third of all females attaining the size of the smallest gravid female showed no signs of reproductive activity despite mating opportunities, suggesting that not all females reproduce annually in this population.

The flower of the oriental orchid Cymbidium floribundum is known to attract the Japanese honeybee Apis cerana japonica. This effect is observed not only in workers but also drones and queens; that is, it attracts even swarming and absconding bees. A mixture of 3-hydroxyoctanoic acid (3-HOAA) and 10-hydroxy-(E)-2-decenoic acid (10-HDA) was identified as the active principles from the orchid flower, whereas these compounds individually have no such activity. Both compounds are also mandibular gland components of worker honeybees with related compounds. This strongly supports the idea that orchid flowers mimic bee secretions, although the ecological consequences of this relationship remain unknown. Because the flower is used to capture swarms, the present identification may contribute to the development of new techniques in traditional beekeeping for Japanese bees as well as A. cerana in Southeast Asia.

Two populations of Hollandichthys multifasciatus from headwaters of adjacent river coastal basins in Paraná state, southern Brazil, were cytogenetically studied in order to evaluate intraspecific divergences. Both populations presented 2n = 50 chromosomes, divided into 14m 18sm 18st in the sample from Antonina and 14m 20sm 16st for the population from Guaraqueçaba. Analyses of active nucleolar organizer regions (Ag-NORs) and fluorescent in situ hybridization (FISH) with 18S rDNA probes revealed a single metacentric pair bearing marks at proximal positions on the short arms. The location of the 5S rDNA and GC-rich sites showed chromosomal divergence between both populations. Therefore, several population markers were detected, reflecting a population differentiation, possibly driven by the formation of Paranaguá Bay and Serra do Mar mountain range. Since the existence of a species complex in H. multifasciatus has been previously characterized by morphological, molecular, and karyotype population differentiation, this species needs to be taxonomically studied in detail.

Femoral glands are holocrine structures that produce compounds used by lizards as pheromones. Few studies have investigated the morphology and ultrastructure of these glands. We chose a closely related species pair from a lizard family having femoral glands in male and female of both species to illustrate comparative morphology and ultrastructure and their implications for the mechanism of secretion dispersal to the environment. We also aimed to test whether the structure and mechanism of secretion production differ between related species. In addition, we sought to gain a better understanding of the holocrine mechanism of secretion. Femoral glands of selected sympatric lacertid species, Acanthodactylus boskianus and A. scutellatus were studied comparatively using light microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). SEM revealed both interspecific and sexual variation in the morphology of the glandular pores. The external morphology suggests the mechanism of the secretion deposition where the convex part of pore-carrying scale is probably used to partition the secretory plug. Histology shows the epithelial cells of the gland duct as an extension of the epidermis with its covering keratin. The glandular acini are composed of germinal and secretory cells. The latter undergo four different stages of differentiation, from the beginning of the formation of secretory granules, through the accumulation of these granules, disintegration and formation of the secretory plug, which protrudes externally. The study considers the sequence of holocrine secretion development, and explains in part how such secretions are deposited on the substrate. Sexual differences at the external morphology level were more evident than interspecific differences.

Among mammals, the similarity in body temperature indicates that body size differences in heat loss must match the body size differences in heat production. This study tested the possibility that body surface temperature (Tbs), responsible for heat loss through radiation and convection, may vary systematically with the animal's body mass (M). Tbs was measured by whole body thermography in 53 specimens from 37 eutherian mammals ranging in M from a few grams to several tons. Numerous thermographs were taken from all angles, indoor, with the animals standing still in absence of air convection and of external radiant sources, at the ambient temperature of 20–22°C, 22–25°C, or 25–27°C. Data were analysed as whole body surface average, as average of the “effective” body surface area (those regions with temperatures exceeding ambient temperature by > 1.5°C or by > 5°C), as the peak histogram distribution and as average of the regions with the top 20% temperature values. For all modes of data analysis and at all ambient temperatures Tbs was independent of the animal's M. From these data, the heat loss by radiation and natural convection combined was estimated to vary to the 2/3 power of M. It is concluded that, for the same ambient conditions, the surface temperature responsible for radiation and convection is essentially bodysize independent among mammals.

Testis differentiation in anuran amphibians is the result of two opposing processes: degeneration of the distal part, and development of the proximal part, which becomes a functional male gonad. Undifferentiated gonad differentiates directly into a testis without a transition phase. We described the morphology of developing testes in Rana temporaria and Hyla arborea, and made careful histology and ultrastructure in Pelophylax lessonae. The developing testis was divided into 10 stages (I–III, undifferentiated gonad, IV–X, testis). The earliest morphological symptoms of testis differentiation were observed in 4- to 5-week-old tadpoles at Gosner stage 27–28. At that time an undifferentiated gonad, composed of 6–9 metameres, differentiates into a testis. The proximal metameres (2–3 in the right gonad and 3–4 in the left one) differentiate into a functional testis, while the distal ones degenerate. The difference between left and right gonad size is maintained until adulthood (stage X). Degeneration of the distal part progresses along the posterior-anterior gradient and starts at stage IV. It affects first the germ cells with accompanying precursor Sertoli cells, and then the mesenchymal cells and fibroblasts. Finally the external epithelium forms a “sleeve” around the almost empty distal part. The total length of the testes stays the same until stage VIII at Gosner stage 41 (age 74–148 days). Active spermatogenesis starts at stage IX (juveniles after their first hibernation), during which the distal part eventually disappears and the proximal part starts growing considerably due to progressing spermatogenesis.

It has been reported that endocrine disrupter compounds (EDCs) interfere with the endocrine system, mimicking the action of sex steroid hormones in different species of mollusks. Prosobranchs are frequently used as a reliable bioindicator to evaluate EDC exposure. In this article, we evaluate the effects of the xenoestrogen 4-n-nonylphenol (NP) in the prosobranch gastropod Patella caerulea, which exhibits protandrous hermaphroditism as its reproductive strategy. We isolated a partial sequence of a GnRH-like molecule from the gonads of Patella caerulea. The deduced amino acid sequence is highly homologous to that reported for the Lottia gigantea GnRH. Patella caerulea GnRH (pGnRH) mRNA expression is widespread in both male and female germ lines during gametogenesis. We suggest pGnRH as a novel biomarker for the early assessment of presence of EDCs and monitoring short and long-term impacts on Patella caerulea community structure.