Amphipod crustaceans and environmental disturbance: a review

This review of the literature shows that amphipod crustaceans create disturbance through predation on commercial harvests, attacks on macroalgae, introductions as exotic species, and interference competition. Amphipods are also affected by disturbance events, both man-made and natural. Anthropogenic disturbance includes environmental alteration by toxins, oil, organic enrichment, acidification, salinity alteration, and ships' wakes. Natural disturbances are space clearance by the feeding activities of other fauna, and physical disturbance by sediment erosion and ice scour.     

Terrestrial isopods and myriapods in a forested scree slope: subterranean biodiversity,depth gradient and annual dynamics

Diversity, depth distribution and seasonal activity of isopods and myriapods were studied using subterranean traps buried in a forested limestone scree slope in the ?ierna Hora Mts, Western Carpathians, Slovakia, throughout the depth gradient from 5 to 95 cm. A total of five isopod, 13 diplopod and 11 chilopod species were identified. Most edaphic species strongly preferred the uppermost organic soil layers. Among the species captured, some represented rare stenoecous Carpathian endemics, namely the isopod Trichoniscus carpaticus, and diplopods Julus curvicornis and Leptoiulus mariae. Others were subterranean forms, partly adapted to hypogean conditions: the isopod Mesoniscus graniger, and diplopods Mecogonopodium carpathicum and Trachysphaera costata. The annual activity in the vast majority of the species ceased completely in winter, and was gradually relaunched in spring. In evaluating the age structure of two predominant diplopods Polydesmus denticulatus and Mecogonopodium carpathicum, both widespread across the depth gradient, a vertical segregation of early post-embryonic stages was found. While P. denticulatus tended to undergo the early stages of development in the soil-filled topmost levels, the early juvenile stage of M. carpathicum was distributed deep in the scree slope profile.     

Biology and life cycle of Tmetonyx similis (G. O. Sars, 1891) (Amphipoda,Lysianassidae), a scavenging amphipod from the continental slope of the Mediterranean

The present study focused on the biology and life cycle of Tmetonyx similis, a scavenging amphipod inhabiting the continental slope of the north‐western Mediterranean. All the categories of individuals were observed in the samples. The emergence of offspring occurs in successive cohorts. The lifespan of the females is longer than that of the males, but the sex ratio is strongly in favour of the males. The fecundity was found to be lower than that of the other female crustaceans present in these samples. The growth pattern was modelled. A strong correlation was observed between the length and the weight of the animals collected. Several hypotheses are proposed to explain a sex ratio in favour of males. This result may be explained by a migratory process of the females of T. similis. A comparison of the reproduction strategy is given for the three main scavenger crustacean species (amphipods and isopod) collected in this area.     

Biodiversity and biogeography of the coral boring barnacles of the genus Berndtia (Cirripedia: Acrothoracica) in the West Pacific,with description of three new species

Acrothoracican barnacles of the genus Berndtia are exclusive coral borers and the type species is Berndtia purpurea Utinomi, 1950a, reported in the corals Lepastrea purpurea and Psammocora profundacella in Wakayama, Japan. We confirmed the type is only from the coral Lepastrea purpurea and is distributed from Japan, Taiwan to Hong Kong. In contrast, B. purpurea from Psammocora belongs to a new species Berndtia haradai sp. nov., which is distributed from Japan to Okinawa. The other new species identified in the present study, Berndtia denticulata sp. nov. is common in Okinawa but also collected on the Pacific side of the Philippines. Berndtia utinomii sp. nov. is found on NE coast of Taiwan, Kochi and Wakayama in Japan and Vietnam but is absent from Okinawa. All described species are diagnostic in the coloration and morphology of the opercular bars in live specimens, morphology of posterior lobes of operculum and the number of notches in maxillules.

http://zoobank.org/urn:lsid:zoobank.org:pub:8B6FE5B4-C5DD-48DE-B91A-39BBBAF87636     

Biology and life cycle of Scopelocheirus hopei (A. Costa, 1851), a scavenging amphipod from the continental slope of the Mediterranean

The biology of Scopelocheirus hopei, a deep-sea (500 m) scavenging amphipod that lives on the continental slope of Mediterranean canyons, was studied. Animals were collected using a baited trap. A new method was developed for reproducibly measuring the exact length of the animals. All the categories of individuals were always present in the samples. The emergence of offspring occurs in successive cohorts. Individuals of the two sexes do not grow at the same rate: the males grow more quickly than the females, but their lifespans are shorter. The males are always less numerous than the females. Two production cycles occur. The females produce offspring all year round. The mean fecundity was found to be 218 eggs per female. The growth pattern was modelled. A strong correlation was observed between the length and the weight of the animals collected. Several hypotheses are proposed to explain the results obtained.     

Vertical distribution of liverwort communities and their relationship with environmental factors in a karst sinkhole in south-western China

ABSTRACT

Understanding the relationships between the vertical distribution of liverwort communities and associated environmental factors is vital for biodiversity conservation in karst sinkholes. The abundance index, α and β diversity indices were used to analyse the characteristics of liverwort communities in the Monkey-Ear Sinkhole (280 m deep, entrance diameter 300 m, width 280 m). A Generalised Linear Model was used to study the vertical distribution of liverwort communities, and the relationships between their vertical distribution and environmental factors were analysed with Canonical Correspondence Analysis. Forty-two liverwort taxa from 22 genera in 19 families were identified in the sinkhole. The liverwort assemblages were dominated by the families Plagiochilaceae and Lejeuneaceae. The α and β diversity appeared to fluctuate randomly among the four depths sampled. The highest degree of environmental heterogeneity was found at the lower-middle section of the sinkhole; liverwort community diversity at the base was much higher than that found at the upper, middle or lower-middle sections. The environment at the base of the sinkhole was more complex than at the other three depths, providing a range of habitats that facilitated the coexistence of multiple liverwort communities. The abundance of species, genera and families in liverwort communities followed the sequence: base > upper section > middle section > lower – middle section. There were significant differences in liverwort communities at the four depths. In the sinkhole, liverwort communities fell into three distribution groups: wide, moderate or narrow distribution along the vertical direction. The communities with a broad distribution, found from the upper section to the base, were affected by a combination of light, humidity and temperature, and were classified as mixed factor dependent; those with a moderate distribution found mostly in the mid and lower-middle sections were primarily dependent on temperature and humidity, and were classified as temperature and humidity dependent; and those with a narrow distribution found at the base of the sinkhole were mainly influenced by humidity, and were classified as humidity dependent.     

Multi-scale patterns in the host specificity of plant-dwelling arthropods: the influence of host plant and temporal variation on species richness and assemblage composition of true bugs (Hemiptera)

The influence of temporal variation in the host specificity of invertebrates to estimates of biodiversity is rarely considered. While patterns at large spatial scales have stimulated much attention, such comparisons are constrained for southern-hemisphere biomes because the patterning of invertebrates on plants is largely unknown. Here, we analyse variation of plant-dwelling Hemiptera from 15 understorey plant species over 18 months in the south-west Australian biodiversity hotspot. Analyses showed significant interactions in species composition between sampling period and plant species. Fauna that were “effectively specialized” (host-specificity index) to plants changed with season, although this was also related to the number of singletons and overall species richness. Sampling from a single season also overestimated the degree of host specificity by 52% and underestimated the perception of species richness when an outbreak of a particular herbivore occurred. High host-specificity values (12.7 hemipteran species per plant) support the case for high estimates of global arthropod richness.     

The first record of Syncarida in Montana,USA: a new genus and species of Parabathynellidae (Crustacea,Bathynellacea) in North America

Montanabathynella salish gen. nov. sp. nov., of the family Parabathynellidae, from Montana, USA, is described. The new species displays several exclusive characters: distal endite of the maxillule with nine claws and a very large and distinctive male thoracopod 8 with four lobes in the basal penial region and a long recurved exopod without setation. It also presents a unique combination of characters: antennule seven‐segmented; antenna six‐segmented; labrum with 18 teeth; exopod of thoracopods three‐ to six‐segmented, endopod with one dorsal seta on the first and second segments and epipod only present on thoracopods 4 to 7; pleopods absent; endopod of thoracopod 8 male with two setae and exopod without setae; female thoracopod 8 having two segments, first segment with two groups of denticles and the second one with three long barbed setae; 15 spines on sympod, four spines and spinous process on endopod and 12 setae on exopod of uropod.     

A new species and illustrated records of Paracyclops Claus, 1893 (Copepoda: Cyclopoida: Cyclopinae) from Mexico

A new species of the freshwater cyclopid genus Paracyclops Claus, 1893 collected from the state of Aguascalientes, Mexico is described based on female and male specimens. It has affinities with other forms with profusely ornamented caudal rami, such as Paracyclops carectum Reid and Paracyclops pilosus Dussart, but it can be distinguished by a combination of characters including details of the ornamentation of the coxa of leg 1, third antennular segment with incomplete suture line, inner margin of the caudal rami with scattered hair-like elements, and relatively long caudal rami, among other characters. The male is distinguished mainly by having the caudal rami completely covered by pilosity, which differs from all other known Paracyclops, including Paracyclops carectum. The new species has affinities with neotropical Paracyclops. Illustrated records and a morphological analysis of two more species of Paracyclops from Mexico, Paracyclops poppei and Paracyclops chiltoni, are also included in this contribution.     

A new genus and species of Syncarida (Crustacea: Malacostraca) from Borneo

A new genus and species of the family Parabathynellidae, Sabahbathynella wongi, is described. It has been discovered in the interstitial of coarse sand filling the spaces between big stones of the bank along a stream in Sabah on Borneo. The new genus of the family Parabathynellidae exhibits some unusual features which make it impossible to assess its phylogenetic position. There are some convergencies with the genus Thermobathynella.     

The first record of the genus Vejdovskybathynella Serban and Leclerc, 1984 (Syncarida,Bathynellacea, Bathynellidae) in the Iberian Peninsula: three new species

Three new species of the genus Vejdovskybathynella are described from caves in northern Spain. It is the first time that this genus has been documented in the Iberian Peninsula. Vejdovskybathynella edelweiss n. sp. has several unique features: the setal formula of the antenna (0/2+exp/2+0/1+0/0+0/2+2/4); the form of the segments and claws of the mandibular palp of the mandible of the male; exopod of the female thoracopod VIII similar in size to the endopod (exopod is always longer than the endopod); small frontal projection of the basipod of the male thoracopod VIII, large or very large is common; the form and size of the lobes of the male thoracopod VIII is unique; the second spine of the furcal rami 2.5 times longer than the first spine. Vejdovskybathynella caroloi n. sp. has a unique male thoracopod VIII with a spur in the exopod that is a feature unknown in the genus, and additionally, this species has the smallest endopod of the thoracopod VIII male of the entire genus; the presence of three aesthetascs in segments VI and VII of the antennule had not been observed in this genus until now; the form of the segments of the mandibular palp of the mandible of the male are unique; the distal spine of the sympod of the uropod is larger than in other species, whereas in the rest of the species of the genus they are equal in size. Vejdovskybathynella pascalis n. sp. is the smallest species of the genus and has two and three aesthetascs in segments VI and VII of the antennule, respectively; it is the only species of the genus that has one seta on segment I and two setae on segment IV of the antenna; it has a unique male thoracopod VIII with a small spur on the frontal projection of the basipod and with the endopod larger than all other species in spite of its small size; the basal spine of the sympod of the uropod is smaller than the other three.     

Annotated checklist and distribution of Culicoides biting midges of Ukraine (Diptera: Ceratopogonidae)

Despite the great socio-economic impact of Culicoides-borne diseases, there is little work on the reassessment of the faunistic and distributional data on this important group of vectors in the territory of Ukraine. Along with the literature review, materials were collected and slide-mounted using the conventional techniques for this study. The revised and commented list of 55 valid species names of the genus Culicoides recorded from Ukraine and their distribution is presented. New collection localities are given for Culicoides griseidorsum Kieffer, Culicoides atripennis Shevchenko and Culicoides newsteadi s.l. Culicoides triangulatus Shevchenko and Culicoides ukrainensis Shevchenko described from Ukraine are recognized as nomina dubia, whereas Culicoides tentorius Austen and Culicoides furcillatus Callot, Kremer and Paradis were excluded from the list. The current state of knowledge on Ukrainian Culicoides fauna should be characterized as rather understudied. Collectively, this suggests that further research efforts are needed, especially in view of the fact that the species recognized as vectors of the economically important diseases of animals are among the most abundant representatives of the genus. Moreover, the article highlights taxonomic problems within certain taxa and provides an outline of its further research perspectives.     

Diversity and dispersal history of the talitrids (Crustacea: Amphipoda: Talitridae) of Bermuda

Five taxa of talitrid amphipods were found in the archipelago of Bermuda, of which three were recorded there for the first time. Four of these are supralittoral wrack generalists: Platorchestia monodi BOLD:AAB3402, (a unique Molecular Operational Taxonomic Unit according to the Barcode Index Number system), a related species recognized by molecular methods, Platorchestia platensis BOLD:AAA2949, Mexorchestia carpenteri carpenteri BOLD:AAC1491 and Tethorchestia antillensis; and one a terrestrial leaf-litter generalist: Talitroides alluaudi. A key is provided to discriminate between the formally described talitrids of Bermuda. Dispersal mechanisms from the American continent to Bermuda were considered for all taxa based on species distributions along the North American Atlantic coast and also investigated by molecular methods, using genetic population differentiation and haplotype network analysis based on the barcode region of cytochrome c oxidase subunit I gene. For P. monodi BOLD:AAB3402 the genetic results suggest that some dispersal events occurred before human colonization of Bermuda but are equivocal about the source population and therefore the direction of dispersal. Some very recent synanthropic dispersal is possible with this species. For the other two species studied genetically, P. platensis BOLD:AAA2949 and M. c. carpenteri BOLD:AAC1491, the small population samples analysed support dispersal to Bermuda from the American mainland, before human occupation of Bermuda, although the available sample size was limited for these species. The available limited direct, non-genetic evidence supports synanthropic transport for Talitroides alluaudi. Platorchestia monodi BOLD:AAB3402 is found in the same wrack habitat as P. platensis BOLD:AAA2949 on Bermuda, apparently without interbreeding. No evidence was found that driftwood specialist talitrids had become established in Bermuda.     

The freshwater crustaceans (Cladocera: Copepoda) of Bering Island (Commander Islands,Russian Far East): species richness and taxocene structure

The crustaceans of the fresh waters of Bering Island and their link to the fauna of adjacent regions were studied. Based on original data and existing literature, the species composition of Cladocera and Copepoda was described. The compiled list includes 22 species of Cladocera and 30 species of Copepoda. In the original data, 35 species native to the Commander Islands were reported for the first time. Six species were newly reported in the Far East, and two were newly reported in Russia. The ecological peculiarities of several species and some biogeographical features of the freshwater zooplankton of the island are discussed. The main part of the fauna of the island form Holarctic widespread species (64.3%), another slightly smaller group of the fauna is comprised of Palaearctic species (20.1%), and the remainder comprise Nearctic (6.7%) and Beringian species (8.9%). Particular patterns in the distribution of freshwater zooplankton and the factors underlying the occurrence of these species on the island are considered.     

The first record of Bathynellacea from Thailand: a new genus and species of Parabathynellidae (Crustacea: Syncarida)

A new genus and species of the family Parabathynellidae, Siambathynella laorsriae gen. nov. et sp. nov. is described from Thailand. The new genus displays an exclusive character: a distinctive male thoracopod VIII with a row of denticles on the basipod. The new species also displays a unique combination of morphological characters, including a seven-segmented antennule, seven-segmented antenna, sexual dimorphism on the antennule, exopod of thoracopod I one-segmented, exopod of thoracopod II–VII two-segmented, male thoracopod VIII lacking basipodal seta, female thoracopod VIII with two setae, lacking pleopods, sympod of the uropod with inhomonomous row of spines, and endopod of uropod with a spinous distal process and a large distal spine ornamented with rows of setules. This is the first record of Bathynellacea (family Parabathynellidae) in Thailand, extending the distributional range of this taxon in Asia.     

A new superfamily,family, genus and species of marine amphipod,Protodulichia scandens,from Japan (Crustacea: Amphipoda: Senticaudata: Corophiida)

ABSTRACT

In this study, the new amphipod superfamily Protodulichioidea and family Protodulichiidae are established. Both belong to the infraorder Corophiida but is different from all known superfamilies and families. Amphipods included in the new superfamily and family are characterised by having a triangular head with large eyes, extremely long pereopod 7, and uropod 3 with a short peduncle and slender rami bearing a few robust setae. Protodulichia scandens gen. et sp. nov. is fully described here and its mast-building behaviour is also recorded.

urn:lsid:zoobank.org:pub:F6613B27-D954-4E4C-86CB-9FC5E9624334     

Deltochilini and Phanaeini dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) in introduced and native ecosystems of Brazil

The dung beetle tribes Deltochilini and Phanaeini (Coleoptera: Scarabaeidae: Scarabaeinae) play an important ecological role in the habitats in which they live. Despite much field work on these beetles in the Neotropical region, biological information on many taxa is still unknown. Here we provide information on species of Deltochilini and Phanaeini including temporal distribution of adults, sex ratio (Male : Female) and measurements of the individuals as well as on ecology and general biology of all species sampled in introduced (pasturelands of Brachiaria spp.) and native (patch of the Brazilian savanna) ecosystems of Brazil. Furthermore, our findings may help to understand the complexity of the effects of mixed ecosystems on the biodiversity of dung beetles.