New troglobitic species of Niambia from Botswana and Namibia (Crustacea, Isopoda, Oniscidea)

Three new species in the genus Niambia are described from southern African caves: N. botswanaensissp. nov. from Diviner’s Cave (Botswana), N. ghaubensissp. nov. from Ghaub Cave and N. namibiaensissp. nov. from Märchen Cave (Namibia). All these species show troglomorphic traits such as absence of body pigmentation and eyes. These are the first troglobitic species recorded in the genus. Most of the other species of Niambia are epigean and occur in semi-arid environments in the Afrotropical Region.

Parallel shifts of visual sensitivity and body colouration in replicate populations of extremophile fish.

Visual sensitivity and body pigmentation are often shaped by both natural selection from the environment and sexual selection from mate choice. One way of quantifying the impact of the environment is by measuring how traits have changed after colonization of a novel habitat. To do this, we studied Poecilia mexicana populations that have repeatedly adapted to extreme sulphidic (H2S containing) environments. We measured visual sensitivity using opsin gene expression, as well as body pigmentation and water transmission for populations in four independent drainages. Both visual sensitivity and body pigmentation showed significant parallel shifts towards greater medium wavelength sensitivity and reflectance in sulphidic populations. The light spectrum was only subtly different between environments and overall, we found no significant correlations between the light environment and visual sensitivity or body pigmentation. Altogether we found that sulphidic habitats select for differences in visual sensitivity and pigmentation; our data suggest that this effect is unlikely to be driven purely by the water's spectral properties and may instead be from other correlated ecological changes.

New species of bristletails of the family Machilidae (Microcoryphia) from caves in Abkhazia and Ukraine

Two new species of bristletails of the family Machilidae are described from caves in the Western Caucasus (troglophile Coryphophthalmus troglophilus sp. nov.) and in the Eastern Carpathians (trogloxene Trigoniophthalmus ukrainensis sp. nov.). The main morphological adaptations of C. troglophilus sp. nov. to life in caves include green eye color; weak body pigmentation; well-developed arolium and claws; relatively long cerci, tarsae and tibiae of the hind legs; long apical needles of the urostyli; large sublateral spines on urocoxites IX. C. troglophilus sp. nov. resembles C. abchasicus (Kaplin, 2017), but they are distinguishable in color of eyes, ratio of eye contact to length, length of cerci, structures of the labial palps, legs, urocoxites IX, ovipositor, and parameres. Trigoniophthalmus ukrainensis sp. nov. has no recognized morphological adaptations to life in caves. This species resembles T. alternatus (Silvestri, 1910), but they are easily distinguished in the number of annuli in distal chains of flagellum, ratio of width to length of paired ocelli, chaetotaxy of male maxillary and labial palps.

Many ways to make darker flies: Intra- and inter-specific variation in Drosophila body pigmentation components

ABSTRACTBody pigmentation is an evolutionarily diversified and ecologically relevant trait that shows variation within and between species, and important roles in animal survival and reproduction. Insect pigmentation, in particular, provides some of the most compelling examples of adaptive evolution and its ecological and genetic bases. Yet, while pigmentation includes multiple aspects of color and color pattern that may vary more or less independently, its study frequently focuses on one single aspect. Here, we develop a method to quantify color and color pattern in Drosophila body pigmentation, decomposing thorax and abdominal pigmentation into distinct measurable traits, and we quantify different sources of variation in those traits. For each body part, we measured overall darkness, as well as four other pigmentation properties distinguishing between background color and color of the darker pattern elements that decorate the two body parts. By focusing on two standard D. melanogaster laboratory populations, we show that pigmentation components vary and co-vary in different manners depending on sex, genetic background, and developmental temperature. By studying three natural populations of D. melanogaster along a latitudinal cline and five other Drosophila species, we then show that evolution of lighter or darker bodies can be achieved by changing distinct component traits. Our study underscores the value of detailed phenotyping for a better understanding of phenotypic variation and diversification, and the ecological pressures and genetic mechanisms underlying them.

Expression of extraocular opsin genes and light-dependent basal activity of blind cavefish

Background Animals living in well-lit environments utilize optical stimuli for detecting visual information, regulating the homeostatic pacemaker, and controlling patterns of body pigmentation. In contrast, many subterranean animal species without optical stimuli have evolved regressed binocular eyes and body pigmentation. Interestingly, some fossorial and cave-dwelling animals with regressed eyes still respond to light. These light-dependent responses may be simply evolutionary residuals or they may be adaptive, where negative phototaxis provides avoidance of predator-rich surface environments. However, the relationship between these non-ocular light responses and the underlying light-sensing Opsin proteins has not been fully elucidated. Methods To highlight the potential functions of opsins in a blind subterranean animal, we used the Mexican cave tetra to investigate opsin gene expression in the eyes and several brain regions of both surface and cave-dwelling adults. We performed database surveys, expression analyses by quantitative reverse transcription PCR (RT-qPCR), and light-dependent locomotor activity analysis using pinealectomized fish, one of the high-opsin expressing organs of cavefish. Results Based on conservative criteria, we identified 33 opsin genes in the cavefish genome. Surveys of available RNAseq data found 26 of these expressed in the surface fish eye as compared to 24 expressed in cavefish extraocular tissues, 20 of which were expressed in the brain. RT-qPCR of 26 opsins in surface and cavefish eye and brain tissues showed the highest opsin-expressing tissue in cavefish was the pineal organ, which expressed exo-rhodopsin at 72.7% of the expression levels in surface fish pineal. However, a pinealectomy resulted in no change to the light-dependent locomotor activity in juvenile cavefish and surface fish. Therefore, we conclude that, after 20,000 or more years of evolution in darkness, cavefish light-dependent basal activity is regulated by a non-pineal extraocular organ.

First record of albinism for the doglike bat, Peropteryx kappleri Peters, 1867 (Chiroptera, Emballonuridae)

Albinism is a type of deficient in melanin production could be the result of genetic anomalies that are manifest as the absence of coloration of part or the entire body of an organism. This type of chromatic disorder can affect several vertebrate species, but is rarely found in nature. Among bats, more than 450 cases of total or partial loss of body pigmentation have been reported. Herein we provide the first report of albinism for the bat species Peropteryxkappleri (Chiroptera: Emballonuridae) with two such specimens being observed from iron formation caves in a conservation unit “Floresta Nacional de Carajás”, Amazon forest, northern of Brazil.

Occurrence of tayras (Eira barbara Linnaeus, 1758) with anomalous coloration in Cerrado remnants in the state of São Paulo, Brazil

Coloration anomalies are mainly genetically-based disorders in which body pigmentation is either reduced (hypopigmentation) or produced in excess (melanism), in parts or the totality of the body. Cases of hypopigmentation have been documented in many neotropical mammals, including the tayra (Eira barbara Linnaeus, 1758). We expand the account of anomalous coloration occurrence presenting new registers of hypopigmented tayras in Brazil. Data was collected during a mammal survey carried out in three agricultural landscapes within the Cerrado domain in the northeast of the state of São Paulo. We obtained two kinds of records of hypopigmented tayras, one from direct sighting and the other from a camera-trap. We discuss the likely implications of this conspicuous coloration to tayras and highlight some possibilities of study.