Concerted variation in melanogenesis genes underlies emergent patterning of plumage in capuchino seedeaters

Coloration traits are central to animal communication; they often govern mate choice, promote reproductive isolation and catalyse speciation. Specific genetic changes can cause variation in coloration, yet far less is known about how overall coloration patterns—which involve combinations of multiple colour patches across the body—can arise and are genomically controlled. We performed genome-wide association analyses to link genomic changes to variation in melanin (eumelanin and pheomelanin) concentration in feathers from different body parts in the capuchino seedeaters, an avian radiation with diverse colour patterns despite remarkably low genetic differentiation across species. Cross-species colour variation in each plumage patch is associated with unique combinations of variants at a few genomic regions, which include mostly non-coding (presumably regulatory) areas close to known pigmentation genes. Genotype–phenotype associations can vary depending on patch colour and are stronger for eumelanin pigmentation, suggesting eumelanin production is tightly regulated. Although some genes are involved in colour variation in multiple patches, in some cases, the SNPs associated with colour changes in different patches segregate spatially. These results suggest that coloration patterning in capuchinos is generated by the modular combination of variants that regulate multiple melanogenesis genes, a mechanism that may have promoted this rapid radiation.

Image analysis of real-time classification of cherry fruit from colour features

An image analysis algorithm for the classification of cherries in real time by processing their digitalized colour images was developed, and tested. A set of five digitalized images of colour pattern, corresponding to five colour classes defined for commercial cherries, was characterized. The algorithm performs the segmentation of the cheery image by rejecting the pixels of the background and keeping the image features corresponding to the coloured area of the fruit. A histogram analysis was carried out for the RGB and HSV colour spaces, where the Red and Hue components showed differences between each of the specified colour patterns of the exporting reference system. This information led to the development of a hybrid Bayesian classification algorithm based on the components R and H. Its accuracy was tested with a set of cherry samples within the colour range of interest. The algorithm was implemented by means of a real time C++ code in Microsoft Visual Studio environment. When testing, the algorithm showed a 100% effectiveness in classifying a sample set of cherries into the five standardized cherry classes. The components of the hardware-software system for implementing the methodology are low cost, thus ensuring an affordable commercial deployment.

Mimicry can drive convergence in structural and light transmission features of transparent wings in Lepidoptera

Müllerian mimicry is a positive interspecific interaction, whereby co-occurring defended prey species share a common aposematic signal. In Lepidoptera, aposematic species typically harbour conspicuous opaque wing colour patterns with convergent optical properties among co-mimetic species. Surprisingly, some aposematic mimetic species have partially transparent wings, raising the questions of whether optical properties of transparent patches are also convergent, and of how transparency is achieved. Here, we conducted a comparative study of wing optics, micro and nanostructures in neotropical mimetic clearwing Lepidoptera, using spectrophotometry and microscopy imaging. We show that transparency, as perceived by predators, is convergent among co-mimics in some mimicry rings. Underlying micro- and nanostructures are also sometimes convergent despite a large structural diversity. We reveal that while transparency is primarily produced by microstructure modifications, nanostructures largely influence light transmission, potentially enabling additional fine-tuning in transmission properties. This study shows that transparency might not only enable camouflage but can also be part of aposematic signals.

Solving the cryptic diversity of the genus Manerebia Staudinger in northern Peru: description of new species and considerations on the biogeographical role of the Huancabamba Deflection (Nymphalidae: Satyrinae: Pronophilina)

The Huancabamba Deflection in the Andes of northern Peru and southern Ecuador is a pivotal area for Neotropical biogeography, where exceptional biodiversity coincides with high rates of endemism. These characteristics are well illustrated within the montane butterfly genus Manerebia Staudinger (Nymphalidae, Satyrinae). Here, six new, apparently endemic species, and two new subspecies, are described from this region: M. inducta Pyrcz & Willmott n. sp., M. ronda Pyrcz & Boyer, n. sp., M. ronda amplia Pyrcz & Boyer, n. ssp., M. punku Pyrcz & Farfán n. sp., M. huamanii Cerdeña & Pyrcz n. sp., M. placida Pyrcz & Willmott n. sp., M. granatus Willmott, Radford & Pyrcz n. sp. and M. prattorum udima Pyrcz & Boyer, n. ssp. A total of 22 species of Manerebia is reported from the study region, as much as half the total number of species in this genus distributed throughout the tropical Andes. The alpha-taxonomy of Manerebia is particularly demanding, as colour patterns have apparently converged among different species making identification virtually impossible in some cases without comparison of their genitalia, which prove taxonomically and phylogenetically highly valuable. On the other hand, several species differ markedly in wing colour patterns and occur at different elevations but have identical genitalia. Furthermore, our data show that DNA barcoding is only partly viable as an alpha-taxonomic tool, as some markedly different species of Manerebia, in terms of external morphology and ecological preferences, are genetically not separable using only COI markers. On the other hand, several species barely differing morphologically are identified based on barcode. Barcodes of 26 species, including 18 from the northern Andes, are studied here, showing strong differences within some taxa previously considered conspecific based on morphological characters, suggesting that their taxonomic status needs to be re-evaluated. In particular, M. trimaculata and the widely distributed polytypic M. inderena may be highly variable species or complexes of several species. A total of 16 species are found north of the Chamaya valley in southern Ecuador and extreme northern Peru, compared to 14 species south of it in northern Peru. The faunal (Jaccard) similarity coefficient of the two adjacent regions is low (0.3), reflecting the role of the Huancabamba Deflection as a biogeographical barrier.

New species of squat lobsters of the genus Munida from Australia

This study reports on new squat lobsters of the genus Munida collected during recent surveys of Australia’s continental margins. We report on 33 species of Munida including seven new species and 14 new range extensions for Australia. More than 500 specimens were collected, mostly from the western continental margin of Australia, but also including a new species from deep water (>2000 m) off Tasmania. We provide new data on the colour patterns of some species and include molecular data from two mitochondrial markers (16S rRNA and COI) to support the taxonomic status of the new species.

High diversity of pimpline parasitoid wasps (Hymenoptera, Ichneumonidae, Pimplinae) from the lowermost Eocene Fur Formation

With an estimated 100,000 extant species, Darwin wasps (Ichneumonidae) are more specious than all vertebrates together. However, only 288 fossil species have been described to date, with hundreds more awaiting formal description in palaeontological collections. One of the largest gaps in our knowledge concerns the ~12 million years between the K-PG mass extinction and the late Ypresian, from which only two species have been formally described, including Pimpla stigmatica Henriksen from the Danish Fur Formation (~55 Ma). Ie here redescribe and reclassify this species in the genus Epitheronia Gupta, n. comb., and describe nine new species from this fossil locality that are consistent with a placement in Pimplinae: Crusopimpla collina n. sp., C. elongata n. sp., C. minuta n. sp., C. rettigi n. sp., C. violina n. sp., Theronia? furensis n. sp., T. nigriscutum n. sp., Xanthopimpla ciboisae n. sp., and X. crescendae n. sp. The diagnosis of the genus Crusopimpla Kopylov, Spasojevic & Klopfstein is amend in the light of the new species. By comparing the preserved colouration between and within specimens of different species, we draw conclusions about the taxonomic usefulness of colour patterns observed in Fur Formation ichneumonids. The number of described species of pimpline parasitoid wasps from Fur is very high when compared to any other fossil deposit, but low with respect to numbers of extant species. Further study and excavation of Fur ichneumonids will certainly reveal an even higher diversity.

Sex differences in behavioural and anatomical estimates of visual acuity in the green swordtail Xiphophorus helleri

Among fishes in the family Poeciliidae, signals such as colour patterns, ornaments, and courtship displays play important roles in mate choice and male-male competition. Despite this, visual capabilities in Poeciliids are understudied, in particular visual acuity, the ability to resolve detail. We used three methods to quantify visual acuity in male and female green swordtails (Xiphophorus helleri), a species in which body size and the length of the male's extended caudal fin (‘sword’) serve as assessment signals during mate choice and agonistic encounters. Topographic distribution of retinal ganglion cells (RGC) was similar in all individuals and characterized by areas of high cell densities located centro-temporally and nasally, as well as a weak horizontal streak. Based on the peak density of RGC in the centro-temporal area, anatomical acuity was estimated to be approximately 3 cycles/degree (cpd) in both sexes. However, a behavioural optomotor assay found significantly lower mean acuity in males (0.8 cpd) than females (3.0 cpd), which was not explained by differences in eye size between males and females. An additional behavioural assay, in which we trained individuals to discriminate striped gratings from grey stimuli of the same mean luminance, also showed lower acuity in males (1-2 cpd) than females (2-3 cpd). Thus, although retinal anatomy predicts identical acuity in males and females, two behavioural assays found higher acuity in females than males, a sexual dimorphism which is rare outside of invertebrates. Overall, our results have implications for understanding how Poeciliids perceive visual signals during mate choice and agonistic encounters.

Solving an old dilemma: are the two sympatric species Lema apicalis and L. reticulosa (Coleoptera, Chrysomelidae, Criocerinae) morphotypes of a single species?

Two species of Lema (Quasilema), L. apicalis Lacordaire, 1845 and L. reticulosa Clark, 1866 are compared and found to be identical based on morphology and behaviour, although they exhibit different colour patterns (Lema (subgenus Quasilema) apicalis Lacordaire, 1845 = Lema (Quasilema) reticulosa Clark, 1866 new synonym). These morphs are sympatric, with distribution in southern Brazil, Argentina, Paraguay, and Uruguay, and feed and oviposit on the same host plant (Vassobia breviflora (Sendtn.) Hunz (Solanaceae)).

Variation in colour signals among Sarracenia pitcher plants and the potential role of areoles in the attraction of flying Hymenoptera

Sarracenia insectivorous plants show a diversity of visual features in their pitchers but their perception by insects and their role in attraction, have received little attention. They also vary in prey composition, with some species trapping more flying Hymenoptera, such as bees. To test the hypothesis of a link between visual signal variability and prey segregation ability, and to identify which signal could attract flying Hymenoptera, we characterised, the colour patterns of 32 pitchers belonging to four taxa, modelled their perception by flying Hymenoptera, and examined the prey they trapped. The pitchers of the four taxa differed in colour patterns, with notably two long-leaved taxa displaying clear areoles, which contrasted strongly in colour and brightness with the vegetative background and with other pitcher areas in the eyes of flying Hymenoptera. These taxa trapped high proportion of flying hymenoptera. This suggests that contrasting areoles may act as a visual lure for flying Hymenoptera, making plants particularly visible to these insects. Prey capture also differed according to pitcher stage, morphology, season and visual characteristics. Further studies on prey visitation are needed to better understand the link between prey capture and attraction feature.

A new alpheid shrimp, Alpheus mannarensis sp. nov. (Crustacea; Decapoda; Alpheidae) from Gulf of Mannar, Southern India

A new species of the genus Alpheus Fabricius, 1798, A. mannarensis sp. nov. is described and represented based on the materials collected from the shallow and rocky reefs, Gulf of Mannar (Thoothukudi waters), Southern India. This is the first report of Alpheus species from the Gulf of Mannar region. The new species is assigned to the Alpheus brevirostris group, and is distinguished from other species of this group by the combination of the following features: rostral ridge lower than orbital hood in lateral view and postrostral carina not extended to the middle of the carapace, palm of major chela with a transverse groove near the base of dactylus, the ultimate segment of the third maxilliped slender, fingers of minor chela of male slightly longer than palm, the first carpal segment of second pereiopods shorter than second segment, merus of third pereiopods slender and unarmed, dactylus of third pereiopods slender and subspatulate, and unique colour patterns of longitudinal light lines on the reddish body.