First detected case of rabbit Haemorrhagic disease virus 2 (RHDV2) in the Irish hare (Lepus timidus hibernicus)

Background Rabbit haemorrhagic disease virus (RHDV) is a Lagovirus, a subgroup of the family Caliciviridae. RHDV2 is a variant first described in France in 2010, and has since spread globally. It has been reported in several Lagomorph species (rabbits, hares, and their relatives) as well as other mammals including voles and shrews. The disease has raised international concerns for its potential impact on population abundance trajectories, particularly as 25% of Lagomorphs are currently Red-Listed by the International Union for the Conservation of Nature (IUCN). The Irish hare (Lepus timidus hibernicus) is a subspecies of the mountain hare, L. timidus, and is endemic to Ireland, making it an Evolutionarily Significant Unit of intrinsic value. Case presentation The first case of RHDV2 was detected in a wild Irish hare in July 2019. The individual exhibited atypical neurological behaviour (running in circles) prior to death. On necropsy, pink tinged foam was seen in the trachea and congestion was noted in the lungs, but there was no evidence of haemorrhages in any other organ. Both the liver and spleen were tested by reverse transcription real time qPCR confirming high levels of RHDV2 RNA. Histopathology confirmed multifocal necrotising hepatitis. Conclusion The Irish hare is susceptible to RHDV2 infection. Further investigation is warranted to explore the clinical, epidemiological, and population biology implications.

A demographic and ecological study of an Italian population of Polyommatus ripartii: the ESU Polyommatus exuberans

Polyommatus exuberans is an evolutionarily significant unit (ESU) of the lycaenid butterfly Polyommatus ripartii. This ESU is known to survive at only two sites in the Susa Valley (NW Italy). Lack of correct management, reforestation and frequent wildfires severely threaten this ESU (listed as endangered species in the most recent IUCN Italian Red List). Although the taxonomic rank of this taxon is still debated, current threats could cause extinction of its two remaining populations before its taxonomic rank and its ecology are clarified. We collected data for the first time on this population at the small site of Mompantero (ab. 10 ha). We used butterfly GPS-positioning and the mark-release-recapture (MRR)-method to estimate its population size (269 individuals), sex-ratio (1.36 M/F), lifespan (4.76 days), density (47/ha) and mobility (median 153 and 33 m for males and females, respectively). Both sexes are equally catchable. Catchability increases around midday and decreases during overcast weather. While the size and density of this small population are comparable to those of other endemic Polyommatus species (such as P. humedasae and P. gennargenti), scarce mobility makes its populations isolated and even more seriously threatened. Implications for insect conservation We suggest that implementing an active management plan, including mowing before July and/or in autumn, and supporting ant diversity, is of immediate importance. Management should be extended to road verges, where the larval host plant (Onobrychis sp.) is abundant, and would thus also serve as corridors to favour dispersion between sites. Our research is the first study to investigate this taxon, thus shedding some light on the ecological and biological aspects that are crucial for long-term survival.

Molecular analysis reveals a cryptic species of Chthamalus (Crustacea: Cirripedia) in the Cape Verde Islands

The intertidal barnacle Chthamalus stellatus has a broad distribution, occurring in the Mediterranean, the east Atlantic shores and east Atlantic Macaronesian Islands (Madeira, the Canaries and the Azores). Traditionally, based on morphological characters, Chthamalus of the Cape Verde Islands were also regarded as C. stellatus. However, using a mitochondrial gene and two nuclear genes, we found that although Chthamalus from Cape Verde is morphologically similar to C. stellatus, there are genetic differences between the two that are larger than those found between different species of Chthamalus. We thus claim that these genetic differences justify the assignment of the Cape Verde populations as an evolutionarily significant unit and a sister clade to C. stellatus. We also show that the connection between taxonomic units that are close to each other lies not only in the resemblance between DNA sequences. We have found that numerous point mutations characterizing the Cape Verde Chthamalus are present as infrequent alleles in C. stellatus, indicating that two close taxonomic units can also share polymorphisms present in their common ancestor.

Morphology of two native catfishes from the Sierra Madre Occidental, México: I. pricei and Ictalurus sp. (Siluriformes: Ictaluridae)

Introduction: Morphotypes of native catfish of the genus Ictalurus (Siluriformes: Ictaluridae) are known to occur in allopatry in the northern Sierra Madre Occidental of Mexico, with only the Yaqui catfish (Ictalurus pricei) taxonomically described. Recent genetic analysis of these morphotypes has revealed the monophyly of the I. pricei complex, which indicates Ictalurus sp. from the Culiacán River and San Lorenzo River basins as its nearest genetic relative and recognizes as an evolutionarily significant unit the Culiacán River and San Lorenzo River morphotypes. Objective: To compare the meristic and morphometric characteristics of the catfish of the Culiacán River basin with its nearest genetic relative, the Yaqui catfish, in order to determine the presence of distinctive morphological characters that support genetic evidence previously reported for these morphotypes. Methods: Catfish specimens were collected during various field expeditions (1990-2012) to remote sites of the Sierra Madre Occidental and conducted in the Yaqui River and Culiacán River basins with the purpose of morphological comparison. Forty-five morphological characters (40 morphometric and five meristic) were examined in 76 adult specimens – 52 Ictalurus sp. and 24 Ictalurus pricei. Three groups were subject to a discriminant function analysis (DFA), including two Ictalurus sp. groups from the Humaya River and Tamazula River sub-basins, representing the Culiacán River basin, and one I. pricei group representing the Yaqui River basin. The standardized measurements and meristic data of the catfish morphotypes were compared by means of DFA. Results: The DFA revealed 12 characters to be significantly different (P < 0.01) among the groups compared. The morphological characters separating the Ictalurus sp. (Culiacán River basin) from the Yaqui catfish were associated with lower anal, pelvic and pectoral fin ray numbers, shorter head and predorsal lengths, shorter longest lateral barbel and longest dorsal ray lengths and a narrower premaxilar dentary plate; and finally longer distances in Ictalurus sp. for dorsal-fin origin to last anal-fin ray base and dorsal-fin origin to posterior end of the adipose fin base. The standardized coefficients for canonical variables 1 and 2 accounted for 85.6 % and 14.4 % of the total variation, respectively. Conclusions: The distinctive morphological characters of the Ictalurus sp. found in the Culiacán River basin, combined with the known mitochondrial evidence for this morphotype, identify it as an evolutionarily significant unit that requires description as a new species based on taxonomical protocols.

Cutthroat Trout: Evolutionary Biology and Taxonomy

<em>Abstract</em>.—Lahontan Cutthroat Trout (LCT) <em>Oncorhynchus clarkii henshawi </em>and Paiute Cutthroat Trout (PCT) <em>O. c. selernis </em>are found in the Lahontan hydrographic basin of northern Nevada, northeastern California, and southeastern Oregon and together form the Lahontan Basin evolutionary lineage of Cutthroat Trout <em>O. clarkii</em>. The Alvord Cutthroat Trout <em>O. c. </em>ssp. native to the Alvord Lake subbasin in the northwestern Lahontan Basin was also part of this lineage but went extinct due to Rainbow Trout <em>O. mykiss </em>introgression in the mid-20th century. Both LCT and PCT are federally listed as threatened under the U.S. Endangered Species Act. Given its historic distribution in a single small stream and both phenotypic and genetic distinctiveness, PCT is currently recognized as a separate evolutionarily significant unit (ESU). For LCT, three ESUs are identified based upon meristic, morphological, ecological, and genetic data. These putative LCT ESUs separate lacustrine forms in the western Lahontan Basin (Truckee, Carson, and Walker River basins) from largely fluvial forms in the eastern Lahontan Basin (Humboldt and Reese River basins) and northwestern Lahontan Basin (Quinn River, Coyote Lake, and Summit Lake basins). The more recent recognition of a much longer evolutionary history of Cutthroat Trout and several influential genetic papers identifying previously unrecognized diversity within Cutthroat Trout have prompted a need to re-evaluate the overall taxonomy of this species. Here, we review earlier literature and draw on new information from recent studies to delineate uniquely identifiable evolutionary units within the Lahontan Basin lineage of Cutthroat Trout. Though in several cases various anthropogenic and natural influences have made definitive conclusions difficult, based on this collective information and the goal of conserving potentially important genetic, evolutionary, and life history diversity, we propose recognition of six uniquely identifiable evolutionary units within the Lahontan Cutthroat Trout lineage: (1) Paiute Cutthroat Trout—upper East Carson River; (2) western Lahontan Basin—Truckee, Walker, and Carson rivers together with Summit Lake; (3) northwestern Lahontan Basin—Quinn River; (4) eastern Lahontan Basin—Humboldt and Reese rivers; (5) Lake Alvord basin—Virgin-Thousand and Trout Creek drainages; and (6) Coyote Lake basin—Willow and Whitehorse rivers.

Resolving taxonomic uncertainty in vulnerable elasmobranchs: are the Madeira skate (Raja maderensis) and the thornback ray (Raja clavata) distinct species?

Skates and rays constitute the most speciose group of chondrichthyan fishes, yet are characterised by remarkable levels of morphological and ecological conservatism. They can be challenging to identify, which makes monitoring species compositions for fisheries management purposes problematic. Owing to their slow growth and low fecundity, skates are vulnerable to exploitation and species exhibiting endemism or limited ranges are considered to be the most at risk. The Madeira skate Raja maderensis is endemic and classified as ‘Data Deficient’ by the IUCN, yet its taxonomic distinctiveness from the morphologically similar and more wide-ranging thornback ray Raja clavata is unresolved. This study evaluated the sequence divergence of both the variable control region and cytochrome oxidase I ‘DNA barcode’ gene of the mitochondrial genome to elucidate the genetic differentiation of specimens identified as R. maderensis and R. clavata collected across much of their geographic ranges. Genetic evidence was insufficient to support the different species designations. However regardless of putative species identification, individuals occupying waters around the Azores and North African Seamounts represent an evolutionarily significant unit worthy of special consideration for conservation management.

Wild dogs and village dogs in New Guinea: were they different?

Recent accounts of wild-living dogs in New Guinea argue that these animals qualify as an ‘evolutionarily significant unit’ that is distinct from village dogs, have been and remain genetically isolated from village dogs and merit taxonomic recognition at, at least, subspecific level. These accounts have paid little attention to reports concerning village dogs. This paper reviews some of those reports, summarises observations from the interior lowlands of Western Province and concludes that: (1) at the time of European colonisation, wild-living dogs and most, if not all, village dogs of New Guinea comprised a single though heterogeneous gene pool; (2) eventual resolution of the phylogenetic relationships of New Guinean wild-living dogs will apply equally to all or most of the earliest New Guinean village-based dogs; and (3) there remain places where the local village-based population of domestic dogs continues to be dominated by individuals whose genetic inheritance can be traced to precolonisation canid forebears. At this time, there is no firm basis from which to assign a unique Linnaean name to dogs that live as wild animals at high altitudes of New Guinea.