Sympatric Occurrence Research Articles

Two new species of the Pterostichus macrogenys species group (Coleoptera, Carabidae) discovered in shallow subterranean habitats in northern Honshu, Japan

Shallow subterranean environments have recently received attention as a habitat for Carabidae beetles, and many new species have been discovered using collection techniques devised for this habitat. We report the discovery of two new species of the macrogenys species group of the Pterostichus subgenus Nialoe Tanaka, 1958, collected by subterranean baited traps in northern Honshu, Japan. Pterostichus shinbodakensis Sasakawa & Itô, sp. n. is described from Mt. Shinbodake, Niigata Prefecture, and P. tateishiyamanus Sasakawa & Itô, sp. n. is described from the southeastern foot of Mt. Tateishiyama, Fukushima Prefecture. Comparative male genital morphology shows that among the known species, the two new species are most closely related to P. falcispinus Sasakawa, 2005 and P. chokaisanus Sasakawa, 2009, respectively. In addition, sympatric occurrence of P. shinbodakensis with a smaller, unidentified species of the species group was also confirmed. The implications of these results for future studies of the macrogenys species group, as well as those of Nialoe, are discussed.

Sympatric occurrence of two species of Pseudopaludicola (Anura: Leptodactylidae) and first record of Pseudopaludicola jaredi Andrade, Magalhães, Nunes-de-Almeida, Veiga-Menoncello, Santana, Garda, Loebmann, Recco-Pimentel, Giaretta & Toledo, 2016 in the state of Maranhão, northeastern Brazil

Here, we document the sympatric occurrence of Pseudopaludicola canga and P. jaredi. We also provide the first record of P. jaredi in the state of Maranhão, northeastern Brazil, expanding this species’ distribution by about 610 km southwestward from Serra das Flores, municipality of Viçosa do Ceará, state of Ceará. Furthermore, we fill the gap in the geographic distribution range of P. canga in the state of Maranhão, extending the distribution of this species by about 530 km southwestward from the municipality of Barreirinhas.

DETECTION OF THE GUAM BIOTYPE (CRB-G) ORYCTES RHINOCEROS LINNEAUS (COLEOPTERA: SCARABAEIDAE) IN PORT MORESBY, PAPUA NEW GUINEA

Oryctes rhinoceros L. is an important pest of coconuts and oil palm. The damage to palms is primarily caused by adult beetles. They either cut through the frond butts or bore through the palm bases with their forelegs and feed on the inner soft tissues. A strain of Oryctes NudiVirus (Rhabdionvirus oryctes) was identified from Malaysia in the 1960s and used effectively for classical biological control of the pest. However, in 2007 a more destructive population of the beetle was found in Guam. Molecular analysis confirmed its genotype to be different from that of the common population and also to be resistant against NudiVirus infection. The new population has subsequently been referred to as the Guam biotype (CRB-G) whilst the common type has been referred to as the Samoan/Pacific biotype (CRB-SIP). In 2010, similar damage was noted on coconuts in Port Moresby, National Capital District, Papua New Guinea. Sympatric occurrence of both CRB-G and CRB-S in National Capital District with no NudiVirus infection on CRB-G has been confirmed. CRB-G has been found to be less responsive to the aggregation pheromone (ethyl 4-methyloctanoate) used for monitoring and control of 0. rhinoceros. Only CRB-S is found in East New Britain, New Ireland and West New Britain with NudiVirus infection. Widespread severe damage was observed in National Capital District and Central Province, whilst severe damage in New Ireland, East New Britain and West New Britain were localised in areas with readily available breeding sites. Light damages were noted in some areas of Milne Bay, Northern and West New Britain Provinces, but most areas were free of damage. The results are discussed in relation to the impact CRB-G is likely to have on the palm industries in Papua New Guinea if no effective control options are put in place. Keywords: Coconut, oil palm, biological control, Rhabdionvirus oryctes, defoliation.

Dynamics of anopheline vector species composition and reported malaria cases during rain and dry seasons in two selected communities of Kwara State

Indoor resting mosquitoes were collected between November 2013 and May 2014 using Pyrethrum spray collection (PSC). The mosquitoes were identified using morphological keys and species specific polymerase chain reaction (PCR) assays. The species composition of members of the An. gambiae complex and reported malaria cases in the selected study communities were spatially mapped using Arc GIS software. A total of 645 mosquitoes were collected from the study sites and morphologically identified. This comprised of 598 (92%) Anopheles species, 42 (7%) Culex species and 5 (1%) Aedes species. One hundredand ninety-six An. gambiaes. l. samples were randomly selected and successfully identified by PCR. The composition of the mosquitoes species collected in Gaa Bolohunduro showed that a higher proportion 53 (64.6%) were An. arabiensis compared to lower proportions 5(6.1%) of An. coluzzii and 24 (29.3%) An. gambiae . In Osin, only 12 (10.5%) were An. arabiensis compared to 13 (11.4%) and 89 (78.1%) identified as An. coluzzii and An. gambiae respectively. The variation in the composition of members of the An. gambiaes. l. identified in Gaa Bolohunduro was not significant ( p =0.070) compared to Osin ( p =0.043). A weak correlation coefficient showed that the predominance of Anopheles in both communities was not dependent on rainfall, though variation in the members of the complex within the wet and dry season was significant ( p <0.01). The sympatric occurrence and availability of An. gambiaes. s. and An. arabiensis during the dry and wet seasons corroborated the high malaria prevalence identified in Ilorin South. This suggests that both vectors will sustain malaria transmission in the study sites. Hence, a vector control strategy in these localities should be informed by the individual behaviour of each vector species identified. Keywords: Anopheles arabiensis, Anopheles coluzzi, Anopheles gambiae , distribution, composition, malaria case

Analysis of bacterial composition in marine sponges reveals the influence of host phylogeny and environment.

Bacterial communities associated with sponges are influenced by environmental factors; however, some degree of genetic influence of the host on the microbiome is also expected. In this work, 16S rRNA gene amplicon sequencing revealed diverse bacterial phylotypes based on the phylogenies of three tropical sponges (Aplysina fulva, Aiolochroia crassa and Chondrosia collectrix). Despite their sympatric occurrence, the studied sponges presented different bacterial compositions that differed from those observed in seawater. However, lower dissimilarities in bacterial communities were observed within sponges from the same phylogenetic group. The relationships between operational taxonomic units (OTUs) recovered from the sponges and database sequences revealed associations among sequences from unrelated sponge species and sequences retrieved from diverse environmental samples. In addition, one Proteobacteria OTU retrieved from A. fulva was identical to sequences previously reported from A. fulva specimens collected along the Brazilian coast. Based on these results, we conclude that bacterial communities associated with marine sponges are shaped by host identity, while environmental conditions seem to be less important in shaping symbiont communities. This is the first study to assess bacterial communities associated with marine sponges in the remote St. Peter and St. Paul Archipelago using amplicon sequencing of the 16S rRNA gene.

Intense genomic reorganization in the genus Oecomys (Rodentia, Sigmodontinae): comparison between DNA barcoding and mapping of repetitive elements in three species of the Brazilian Amazon.

Oecomys Thomas, 1906 is one of the most diverse and widely distributed genera within the tribe Oryzomyini. At least sixteen species in this genus have been described to date, but it is believed this genus contains undescribed species. Morphological, molecular and cytogenetic study has revealed an uncertain taxonomic status for several Oecomys species, suggesting the presence of a complex of species. The present work had the goal of contributing to the genetic characterization of the genus Oecomys in the Brazilian Amazon. Thirty specimens were collected from four locations in the Brazilian Amazon and three nominal species recognized: Oecomys auyantepui (Tate, 1939), Oecomys bicolor (Tomes, 1860) and Oecomys rutilus (Anthony, 1921). COI sequence analysis grouped Oecomys auyantepui, Oecomys bicolor and Oecomys rutilus specimens into one, three and two clades, respectively, which is consistent with their geographic distribution. Cytogenetic data for Oecomys auyantepui revealed the sympatric occurrence of two different diploid numbers, 2n=64/NFa=110 and 2n=66/NFa=114, suggesting polymorphism while Oecomys bicolor exhibited 2n=80/NFa=142 and Oecomys rutilus 2n=54/NFa=90. The distribution of constitutive heterochromatin followed a species-specific pattern. Interspecific variation was evident in the chromosomal location and number of 18S rDNA loci. However, not all loci showed signs of activity. All three species displayed a similar pattern for 5S rDNA, with only one pair carrying this locus. Interstitial telomeric sites were found only in Oecomys auyantepui. The data presented in this work reinforce intra- and interspecific variations observed in the diploid number of Oecomys species and indicate that chromosomal rearrangements have led to the appearance of different diploid numbers and karyotypic formulas.

The Holocene occurrence of Acipenser spp. in the southern North Sea: the archaeological record.

Archaeological sturgeon remains from the southern North Sea basin used to be automatically attributed to Acipenser sturio, since this was the only acipenserid species believed to occur there. These species identifications, however, were in need of revision after a growing number of indications were found for the historical presence of Acipenser oxyrinchus in western Europe. In this study, morphological and genetic data on sturgeon remains from archaeological sites along the southern North Sea are revised. A large number of Dutch, Belgian, British and some French archaeological sturgeon remains, dating from the Mesolithic up to Late Modern times, are morphologically examined and fish sizes are reconstructed. This study of >7000 acipenserid bones proves the sympatric occurrence of European sturgeon A. sturio and Atlantic sturgeon A. oxyrinchus in the southern North Sea at least since the Neolithic (fourth millennium BC onwards), with A. oxyrinchus remains always outnumbering those of A. sturio. Human influence is documented by the decrease in finds through time, but no clear evidence was found for a diachronic change in fish lengths that could possibly be related to fishing pressure.

Fish predation on sympatric and allopatric prey—A case study of Ponto-Caspian gobies, European bullhead and amphipods

Due to the increasing number of biological invasions, more and more non-native species become components of already existing food chains and new interactions develop within communities. In our study, we checked whether (1) the predation preferences depended on sympatric or allopatric occurrence of predator and prey (a predator may choose the well-known prey or rather benefit from the naïvety of the novel one) and (2) fish preferences depended on prey susceptibility to fish predation (ability to hide, active predator avoidance) and/or on its palatability. We studied foraging efficiency of two species of Ponto-Caspian gobies (the round goby Neogobius melanostomus and tubenose goby Proterorhinus semilunaris ) and the European bullhead Cottus gobio on two species of amphipods—Ponto-Caspian Dikerogammarus villosus and non-invasive Gammarus fossarum , occurring in Central and Western Europe. The gammarids were offered to fish with or without shelters and as mobile individuals or immobilized to test the effect of their hiding ability, mobility and palatability on fish predation. Fish selectivity was exhibited only in trials with motile prey, where all tested predators preferred G. fossarum over D. villosus , showing that their selectivity was independent of prey origin. No selectivity was observed for immobilized amphipods. When shelters were present, the predation was lowest. Thus, predator preferences depended on prey behavioural traits (effective shelter utilization and/or activity reduction) rather than on their palatability. Effective predator preference of G. fossarum over D. villosus may be one of the reasons of the successful invasion of the latter to the European inland waters.

Do genes lie? Mitochondrial capture masks the Red Sea collector urchin’s true identity (Echinodermata: Echinoidea: Tripneustes)

Novel COI and bindin sequences of the Red Sea collector echinoid Tripneustes gratilla elatensis are used to show that (1) discordance between mitochondrial and nuclear loci exists in this echinoid genus, (2) Tripneustes gratilla as currently defined possibly comprises a complex of cryptic species, and (3) Red Sea Tripneustes form a genetically distinct clade in the bindin tree, which diverged from other Tripneustes clades at least 2–4million years ago. Morphological reassessment of T. gratilla elatensis shows perfect congruence between identification based on skeletal features and genetic data based on a nuclear marker sequence. Hence the Red Sea Tripneustes subspecies established by Dafni in 1983 is a distinct biological unit.All T. g. elatensis samples analyzed are highly similar to or share mtDNA haplotypes with Philippine T. g. gratilla, as do representatives from other edge-of-range occurrences. This lack of genetic structure in Indo-Pacific Tripneustes is interpreted as a result of wide-spread mitochondrial introgression. New fossil specimens from the Red Sea area confirm the sympatric occurrence of T. g. elatensis and T. g. gratilla in the northern Red Sea during Late Pleistocene, identifying a possible timing for the introgression. In addition, present-day distribution shows a contact zone in the Southern Red Sea (in the Dahlak Archipelago).T. g. elatensis, is yet another example of a Red Sea taxon historically identified as conspecific with its Indo-Pacific relatives, but which turned out to be a morphologically and genetically distinct endemic taxon, suggesting that the level of endemism in the Red Sea may still be underestimated.

Sexual versus Asexual Reproduction: Distinct Outcomes in Relative Abundance of Parthenogenetic Mealybugs following Recent Colonization.

Asexual reproduction, including parthenogenesis in which embryos develop within a female without fertilization, is assumed to confer advantages over sexual reproduction, which includes a “cost of males.” Sexual reproduction largely predominates in animals, however, indicating that this cost is outweighed by the genetic and/or ecological benefits of sexuality, including the acquisition of advantageous mutations occurring in different individuals and the elimination of deleterious mutations. But the evolution of sexual reproduction remains unclear, because we have limited examples that demonstrate the relative success of sexual lineages in the face of competition from asexual lineages in the same environment. Here we investigated a sympatric occurrence of sexual and asexual reproduction in the pineapple mealybug, Dysmicoccus brevipes. This pest invaded southwestern Japan, including Okinawa and Ishigaki Islands, in the 1930s in association with imported pineapple plants. Our recent censuses demonstrated that on Okinawa sexually reproducing individuals can coexist with and even dominate asexual individuals in the presence of habitat and resource competition, which is considered to be severe for this nearly immobile insect. Molecular phylogeny based on partial DNA sequences in the mitochondrial and nuclear genomes, as well as the endosymbiotic bacterial genome, revealed that the asexual lineage diverged from a common sexual ancestor in the relatively recent past. In contrast, only the asexual lineage exhibiting obligate apomictic thelytoky was discovered on Ishigaki. Co-existence of the two lineages cannot be explained by the results of laboratory experiments, which showed that the intrinsic rate of increase in the sexual lineage was not obviously superior to that of the asexual lineage. Differences in biotic and/or abiotic selective forces operating on the two islands might be the cause of this discrepancy. This biological system offers a unique opportunity to assess the relative success of sexual versus asexual lineages with an unusual morphology and life cycle.

Babesia spp. in ticks and wildlife in different habitat types of Slovakia.

BackgroundBabesiosis is an emerging and potentially zoonotic disease caused by tick-borne piroplasmids of the Babesia genus. New genetic variants of piroplasmids with unknown associations to vectors and hosts are recognized. Data on the occurrence of Babesia spp. in ticks and wildlife widen the knowledge on the geographical distribution and circulation of piroplasmids in natural foci. Questing and rodent-attached ticks, rodents, and birds were screened for the presence of Babesia-specific DNA using molecular methods. Spatial and temporal differences of Babesia spp. prevalence in ticks and rodents from two contrasting habitats of Slovakia with sympatric occurrence of Ixodes ricinus and Haemaphysalis concinna ticks and co-infections of Candidatus N. mikurensis and Anaplasma phagocytophilum were investigated.ResultsBabesia spp. were detected in 1.5 % and 6.6 % of questing I. ricinus and H. concinna, respectively. Prevalence of Babesia-infected I. ricinus was higher in a natural than an urban/suburban habitat. Phylogenetic analysis showed that Babesia spp. from I. ricinus clustered with Babesia microti, Babesia venatorum, Babesia canis, Babesia capreoli/Babesia divergens, and Babesia odocoilei. Babesia spp. amplified from H. concinna segregated into two monophyletic clades, designated Babesia sp. 1 (Eurasia) and Babesia sp. 2 (Eurasia), each of which represents a yet undescribed novel species. The prevalence of infection in rodents (with Apodemus flavicollis and Myodes glareolus prevailing) with B. microti was 1.3 % in an urban/suburban and 4.2 % in a natural habitat. The majority of infected rodents (81.3 %) were positive for spleen and blood and the remaining for lungs and/or skin. Rodent-attached I. ricinus (accounting for 96.3 %) and H. concinna were infected with B. microti, B. venatorum, B. capreoli/B. divergens, Babesia sp. 1 (Eurasia), and Babesia sp. 2 (Eurasia). All B. microti and B. venatorum isolates were identical to known zoonotic strains from Europe. Less than 1.0 % of Babesia-positive ticks and rodents carried Candidatus N. mikurensis or A. phagocytophilum.ConclusionOur findings suggest that I. ricinus and rodents play important roles in the epidemiology of zoonotic Babesia spp. in south-western Slovakia. Associations with vertebrate hosts and the pathogenicity of Babesia spp. infecting H. concinna ticks need to be further explored.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1560-z) contains supplementary material, which is available to authorized users.

Unraveling cryptic species diversity in an aposematic sap beetle genus (Coleoptera: Nitidulidae: Cryptarchinae) from northern Europe

The saproxylic sap beetleGlischrochilus(Glischrochilus)quadripunctatus(Linnaeus, 1758), is associated with subcortical habitats of coniferous trees. This species is widely distributed across Europe and Siberia, and is the best known and largest European nitidulid species. A closely related cryptic species,G.(G.)tremulaesp. nov.has been discovered in a xerothermic area of SE Finland in association with old aspens. The two species exhibit a sympatric occurrence in SE Finland, on their respective host trees. We analyze the COI barcode region to compareG.(G.)quadripunctatus,G.(G.)tremulaesp. nov., andG. (Librodor) hortensis(Fourcroy, 1785). Morphological, ecological, and molecular data confirm the presence in SE Finland of twoGlischrochiluss.str. species. We provide a description of the new species. The newGlischrochilusapparently represents a relictual taxon associated with old hollow aspens, and should be considered a species with inherent conservation value within European saproxylic beetle communities.

Sympatry and possible hybridization among species of the killifish genus Aphanius Nardo, 1827 (Teleostei: Cyprinodontidae) in Southwestern Iran

Studies of the taxonomy and present-day distribution of landlocked populations of the killifish Aphanius Nardo, 1827 (Cyprinodontidae) provide a key to understanding their zoogeographic history, and shape conservation strategies and habitat management. Here we report for the first time on the sympatric occurrence of the rare Mesopotamian tooth-carp A. mesopotamicus with a member of the widely distributed common tooth-carp (A. dispar group). Both were found in the Shadegan Wetland of the Mesopotamian drainage system (Southwestern Iran). External characters of individuals, otolith morphology and molecular data based on the cytochrome b gene confirm species identification. The otolith morphology of A. mesopotamicus, hitherto unknown, is strikingly similar to previously described otoliths of A. cf. pluristriatus from the Khonj stream (Southern Iran), which apparently reflects a close relationship between these recently diverged species. Several of the specimens recovered from the Shadegan Wetland showed intermediate characters in pigmentation, otolith morphology and some morphometric values. These specimens are interpreted as putative hybrids, which is additionally supported by a multivariate analysis of the morphometric data. Previous reports suggest that natural hybridization between species of Aphanius results largely from range overlap and range extension. A virtual distribution map derived from climatic modelling studies based on DIVA-GIS (7.5.0) indicates that sympatry of the A. dispar group and A. mesopotamicus is primarily determined by levels of precipitation during the warmest quarter, and is likely to occur only in Southwestern Iran.

Population characteristics and coexistence of puku (Kobus vardonii) and impala (Aepyceros melampus) in and around Kafue National Park, Zambia

Sympatric occurrence of puku (Kobus vardonii) and impala (Aepyceros melampus) characterises large parts of the protected areas in Zambia. The present study assessed traits of the populations as well as spatial and dietary overlap of both antelopes in Kafue National Park and adjacent Game Management Areas in western Zambia. Data were collected via distance sampling along line transects (population and distribution) and via microhistological analyses of dung (diet). Hunting activities might result in fewer males in both antelopes in the Game-Management areas. During the cool dry season there was considerable spatial overlap between puku and impala. However, puku are more abundant in grassland areas, while impala reach highest population densities in intermediate habitats. The diet of puku was characterised by high amounts of grasses during both the cool dry season and the late rainy season. Impala shifted from browsing during the cool dry season to a more grazing diet during the rainy season. This study found niche partitioning via habitat and diet as a key to understand the coexistence of these antelopes and improves our knowledge of Zambian Wildlife.

An eco-epidemiological study of Morbilli-related paramyxovirus infection in Madagascar bats reveals host-switching as the dominant macro-evolutionary mechanism.

An eco-epidemiological investigation was carried out on Madagascar bat communities to better understand the evolutionary mechanisms and environmental factors that affect virus transmission among bat species in closely related members of the genus Morbillivirus, currently referred to as Unclassified Morbilli-related paramyxoviruses (UMRVs). A total of 947 bats were investigated originating from 52 capture sites (22 caves, 18 buildings, and 12 outdoor sites) distributed over different bioclimatic zones of the island. Using RT-PCR targeting the L-polymerase gene of the Paramyxoviridae family, we found that 10.5% of sampled bats were infected, representing six out of seven families and 15 out of 31 species analyzed. Univariate analysis indicates that both abiotic and biotic factors may promote viral infection. Using generalized linear modeling of UMRV infection overlaid on biotic and abiotic variables, we demonstrate that sympatric occurrence of bats is a major factor for virus transmission. Phylogenetic analyses revealed that all paramyxoviruses infecting Malagasy bats are UMRVs and showed little host specificity. Analyses using the maximum parsimony reconciliation tool CoRe-PA, indicate that host-switching, rather than co-speciation, is the dominant macro-evolutionary mechanism of UMRVs among Malagasy bats.

Species coexistence: macroevolutionary relationships and the contingency of historical interactions.

Evolutionary biologists since Darwin have hypothesized that closely related species compete more intensely and are therefore less likely to coexist. However, recent theory posits that species diverge in two ways: either through the evolution of 'stabilizing differences' that promote coexistence by causing individuals to compete more strongly with conspecifics than individuals of other species, or through the evolution of 'fitness differences' that cause species to differ in competitive ability and lead to exclusion of the weaker competitor. We tested macroevolutionary patterns of divergence by competing pairs of annual plant species that differ in their phylogenetic relationships, and in whether they have historically occurred in the same region or different regions (sympatric versus allopatric occurrence). For sympatrically occurring species pairs, stabilizing differences rapidly increased with phylogenetic distance. However, fitness differences also increased with phylogenetic distance, resulting in coexistence outcomes that were unpredictable based on phylogenetic relationships. For allopatric species, stabilizing differences showed no trend with phylogenetic distance, whereas fitness differences increased, causing coexistence to become less likely among distant relatives. Our results illustrate the role of species' historical interactions in shaping how phylogenetic relationships structure competitive dynamics, and offer an explanation for the evolution of invasion potential of non-native species.

Mixed infections of grapevine leaf rusts Phakopsora meliosmae-myrianthae and P. montana in Japan

Mixed infections of grapevine leaves by the grapevine leaf rust fungi Phakopsora meliosmae-myrianthae and P. montana were assumed because of the frequent sympatric occurrences of the two species in Honshu, Japan. This assumption was proven by experimental basidiospore inoculations of Meliosma myriantha and M. tenuis. Basidiospores formed on telial clusters from one rusted grapevine leaf infected both M. myriantha and M. tenuis, resulting in spermogonium and aecium production on the inoculated leaves. However, the aeciospores formed on the two Meliosma species differed; those on M. myriantha were apically thick-walled, characteristic of P. meliosmae-myrianthae, and those on M. tenuis were evenly thin-walled, characteristic of P. montana.

A rose by any other name: systematics and diversity in the Chilean giant barnacle Austromegabalanus psittacus (Molina, 1782) (Cirripedia)

We analyzed the population structure of the edible barnacle Austromegabalanus psittacus (Molina, 1782) along most of the coast of Chile. The analysis of population structure was based on nucleotide sequences of the mitochondrial cytochrome oxidase I (COI) gene region. We also tested for differences between the regions to the north and south of 30-33°S, as these latitudes represent a recognized biogeographic break and important oceanographic transitions occur in that area. No geographic differentiation was evident when using Hudson’s nearest-neighbor ( S nn ) statistic to analyze genetic differences between all populations. F st values nevertheless showed overall genetic structure among sites. Significant geographic structure was found using S nn and analysis of molecular variance (AMOVA) when locations were separated into northern and southern regions, with a stronger signal when the geographic division is set at 33°S. Our results support the idea that oceanographic transitions can affect the genetic structure in species with pelagic larvae. We also discuss observations on size structure differences within the natural range of A. psittacus and this barnacle’s sympatric occurrence with another barnacle, Megabalanus concinnus (Darwin, 1854) in its northern range.

Depredation of Patagonian toothfish (Dissostichus eleginoides) by two sympatrically occurring killer whale (Orcinus orca) ecotypes: Insights on the behavior of the rarely observed type D killer whales

AbstractSympatric forms of ecologically distinctive killer whales (Orcinus orca) have been documented worldwide. This study focused on a new case of such sympatric occurrence of the “Crozet” type and the recently described “type D” killer whales off the Crozet Islands. The two ecotypes are morphologically and genetically distinct, but they both depredate the same local longline fishery. We used observational, photo‐identification, and fishing data, collected between 2003 and 2015, to examine differences in their patterns of depredation. Of the 828 sets where ecotype could be confirmed, type D killer whales interacted with 82 (11%) of the sets, including 9 (1%) sets that were simultaneously depredated by both ecotypes. Associations between the two types were never observed. Type D killer whales typically occurred in larger groups and both ecotypes preferentially depredated Patagonian toothfish (Dissostichus eleginoides). GLMM modeling revealed that the probability of type D depredation significantly increased throughout the study period, especially in deep waters, and photo‐identification data suggested that a subset of all individuals were habituating to depredation. This study documents the partitioning of resources between two distinct ecotypes of killer whales and provides preliminary insight into the feeding ecology of the rare type D killer whale.

When morphological identification meets genetic data: the case ofLucanus cervusandL. tetraodon(Coleoptera, Lucanidae)

The European stag beetle Lucanus cervus, widely distributed across Europe and in some Near East countries, is one of the best known coleopteran species listed in the European Habitats Directive 92/43/EEC and it is considered a flagship species for conservation of saproxylic fauna. Lucanus tetraodon is a closely related species whose geographical distribution is still poorly known and debated. The two species have a sympatric occurrence in central Italy, and in some localities of these areas, many individuals show a mosaic of morphological traits that makes species assignment nearly impossible. We used both mitochondrial and nuclear markers to analyse these specimens. The mitochondrial results evidenced that the two species represent well-defined genetic entities with mitochondrial DNA introgression. This pattern could be the result of either hybridization or of a convergence of morphological characters under local selective pressures in areas of sympatric occurrence. The nuclear marker was polymorphic across the two species and therefore did not reveal hybridization, even if many are the supports to this phenomenon. The most plausible explanation for this genetic pattern is a very recent divergence of the two species which share a common origin and thus a common wg genotype.