Search

Freshwater crayfish are amongst the largest macroinvertebrates and play a keystone role in the ecosystems they occupy. Understanding the global distribution of these animals is often hindered due to a paucity of distributional data. Additionally, non-native crayfish introductions are becoming more frequent, which can cause severe environmental and economic impacts. Management decisions related to crayfish and their habitats require accurate, up-to-date distribution data and mapping tools. Such data are currently patchily distributed with limited accessibility and are rarely up-to-date. To address these challenges, we developed a versatile e -portal to host distributional data of freshwater crayfish and their pathogens (using Aphanomyces astaci , the causative agent of the crayfish plague, as the most prominent example). Populated with expert data and operating in near real-time, World of Crayfish ™ is a living, publicly available database providing worldwide distributional data sourced by experts in the field. The database offers open access to the data through specialized standard geospatial services (Web Map Service, Web Feature Service) enabling users to view, embed, and download customizable outputs for various applications. The platform is designed to support technical enhancements in the future, with the potential to eventually incorporate various additional features. This tool serves as a step forward towards a modern era of conservation planning and management of freshwater biodiversity., Competing Interests: The authors declare there are no competing interests., (©2024 Ion et al.)

Two new species of stream-dwelling crayfish, Cambarus lapidosus, the Stony Fork Crayfish, and Cambarus burchfielae, the Falls Crayfish, are described from the Yadkin River basin in western North Carolina, USA, using an integrative taxonomic approach consisting of morphological, genetic, and biogeographic data. Both species were previously considered to be members of the widely distributed Cambarus species C complex, which occurs throughout mid-Atlantic Slope river basins; however, they are in fact morphologically and genetically more similar to the Cambarus robustus species complex from interior basins in the south-central Appalachians, indicating Atlantic basin stream capture of an Interior basin faunal group has occurred in this region. Both new species described herein can be differentiated from these two complexes, and each other, by several morphological characteristics. Cambarus lapidosus and C. burchfielae are differentiated from C. species C by the absence of cervical spines and the presence of 1-2 subpalmar tubercles on the chelae in most specimens; both species are less-punctate across the areola than C. aff. robustus. Cambarus burchfielae is further differentiated from C. lapidosus, C. species C, and C. aff. robustus by the presence of a narrower and sparsely punctate areola, a single weak row of tubercles on the mesial margin of the palm, and the absence of tubercles on the dorsal surface of the dactyl. The newly described species are genetically sister taxa and together are most similar by genetic distance to undescribed members of the C. robustus species complex from the nearby (~30 km) Watauga River basin and most phylogenetically similar to C. aff. robustus from the adjacent New River basin; both are interior basin drainages. The newly-described species are endemic to the Blue Ridge Mountains of western North Carolina and have restricted distributions (<100 km2-150 km2) in small (<4th order) tributaries to the Yadkin River. Cambarus lapidosus is known only from the upper Stony Fork watershed and C. burchfielae is known only from the upper reaches of the adjacent Lewis Fork watershed; both species likely qualify for conservation status protections under narrow geographic range criteria.

The Cataloochee Crayfish, Cambarus ectopistes sp. nov., is a large, stream-dwelling crayfish that occupies a narrow noncontiguous distribution within the Appalachian Mountain region running through the Upper Tennessee River basin, in the French Broad, Pigeon, and Nolichucky watersheds along the Tennessee and North Carolina border. It is split from the southernmost extent of the C. robustus species complex, and is morphologically and genetically most similar to a second undescribed member of the group endemic to the upper Nolichucky River watershed in North Carolina. Cambarus ectopistes sp. nov. can be distinguished from other members of the C. robustus complex and co-distributed congeners by a combination of characters, including body size, coloration, and morphology of the chela and rostrum. The new species is typically found in channel and edge habitats of moderate to large perennial streams with large cobbles and boulders.

The Jewel Mudbug, Lacunicambarus dalyae sp. nov., is a large, colorful primary burrowing crayfish found in Alabama, Florida, Georgia, Mississippi and Tennessee. This species is most similar in appearance to the Paintedhand Mudbug, L. polychromatus, a species found across the Midwestern United States. The ranges of the two species overlap minimally, and they can be distinguished from each other based on several characters, the most notable of which is the much longer central projection of the gonopod in Form I and II males of L. dalyae sp. nov. relative to L. polychromatus. Like its congeners, L. dalyae sp. nov. is commonly found in burrows in the banks and floodplains of streams and is resilient to a moderate amount of anthropogenic habitat degradation, being occasionally collected from burrows in roadside ditches and urban lawns.

A new species of stream-dwelling crayfish, Cambarus franklini, the South Mountains crayfish, is described from the upper South Fork Catawba River basin in western North Carolina, USA using morphological and genetic data. Cambarus franklini was previously considered a member of the widespread and morphologically variable Cambarus species C complex and is morphologically most similar to an undiagnosed member of the group native to the upper Catawba River basin in NC. Cambarus franklini can be differentiated from this species group by several morphological characteristics including: lacking a well-defined double row of tubercles along the mesial margin of the palm, possessing a more weakly convergent and longer acumen, and conspicuous blue-green and red coloration, particularly throughout the telson and along the distal margins of the rami. This species is phylogenetically most similar to Cambarus johni, Cooper, 2006, another former member of the Cambarus species C group. Cambarus franklini has a limited geographic range (100 km2) and is currently known only from the Henry and Jacob Fork watersheds in the South Mountains region of the Eastern Blue Ridge foothills.

Cambarus acuminatus was described by Walter Faxon in 1884 from three specimens collected from the Saluda River in northwestern South Carolina, USA. Cambarus acuminatus sensu lato has since been acknowledged to comprise a species complex. This complex, also known as Cambarus sp. C, spans a range across much of the Piedmont Plateau and Coastal Plain from central South Carolina north to Maryland and southeastern Pennsylvania. A primary impediment to a much-needed thorough taxonomic assessment and revision of C. sp. C is the absence of taxonomically useful type material of C. acuminatus coupled with the lack of a detailed description of the species. Here we provide a redescription of C. acuminatus based on modern standards for astacoidean crayfishes in the genus Cambarus and emend the circumscription of the species, thereby laying the groundwork necessary for future taxonomic and phylogenetic work within, and involving, the C. sp. C complex.

The obligately parthenogenetic marbled crayfish, Procambarus virginalis, is the first formally described asexual species of the Crustacea Decapoda. It is a triploid descendant of the sexually reproducing slough crayfish, Procambarus fallax. Here we describe the morphology of cultured and wild marbled crayfish of wide size ranges in detail and photodocument all taxonomically relevant characters. Some morphological traits and coloration showed considerable variation within populations despite the monoclonal nature of marbled crayfish. There were also significant differences between wild and laboratory populations with respect to body proportions, coloration and spination. Comparison with Procambarus fallax revealed no qualitative morphological characters that unambiguously identify the marbled crayfish. Analysis of the mitochondrial cytochrome c oxidase subunit I gene (COI) and nuclear microsatellites of marbled crayfish and Procambarus fallax from different sources indicated that the tri-allelic microsatellite PclG-02 is better suitable than COI to identify the marbled crayfish. A respective identification key is provided. The COI and microsatellites of Procambarus fallax from different areas of Florida and southern Georgia suggest that the parents of the first marbled crayfish may have come from northern Union County, northern Florida.

Ostracods of the family Entocytheridae are obligate ectosymbionts of other crustaceans, including crayfishes, isopods, amphipods, and a species of freshwater crab. Entocytheridae, with five subfamilies, 35 genera, and 213 currently accepted species, represents one the most diverse groups of extant freshwater ostracods. Here, we present the results of an extensive literature review, documenting the often complex historical taxonomic activity and resulting classification of Entocytheridae. This overview highlights inconsistencies, errors, and additional sources of confusion that have been inadvertently introduced into the literature, a number of which have remained uncorrected for decades. Also provided is a comprehensive checklist of taxonomic nomenclature and a list of currently accepted names in Entocytheridae.

Cambarus polypilosus sp. nov. is a stream-dwelling crayfish endemic to tributaries in the Buffalo and lower Duck River drainage, and a reach of the lower Tennessee River in the Western Highland Rim of West-Central Tennessee, U.S.A. The new species is closely allied to the three members of the former subgenus Glareocola, but can be differentiated from each by a combination of characters, including body size, coloration, spination, setation, and form I male gonopod morphology. Several meristic measurements and ratios also differentiate C. polypilosus sp. nov. from Cambarus friaufi, to which it is morphologically most similar. Cambarus polypilosus sp. nov. appears to be common in cherty gravel and cobble habitats, where it is typically found in interstices at depths of 0.3 m or more below the substrate surface.

Targeted sampling efforts by the authors for the signal crayfish, Pacifastacus leniusculus, from its native range in the John Day River Basin, Oregon, U.S.A. yielded entocytherid ostracods with a male copulatory complex so clearly different from other entocytherines that a new genus, Aurumcythere gen. nov. is proposed to receive them. This newly proposed, apparently nonsclerotized, genus with hook and spur-like prominences of the posteroventral end of the peniferum is the first new genus of the subfamily Entocytherinae named since Hobbs & Peters described Aphelocythere (= Waltoncythere) in 1977. Aurumcythere gen. nov. represents only the second genus of entocytherid known from the Pacific Northwest. Lack of sclerotization in Aurumcythere gen. nov. provides new insight into poorly understood mating behaviors of entocytherid ostracods.