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Although the barred sand burrower, Limnichthys fasciatus, is widely distributed throughout the western Pacific, including Japan, Taiwan, and Australia, its morphology and genetics are poorly known. We discovered four cryptic species of Limnichthys from the western Pacific based on mtDNA cytochrome c oxidase subunit I (COI) and 16S ribosomal RNA (rRNA) sequences. Genetic distances showed remarkably large differences (12.7%–24.3% in COI and 7.9%–19.6% in 16S rRNA) between true L. fasciatus (type locality: southeastern Australia) and the others. A relaxed clock model with optimized selected substitution models showed that their deep divergence began in the middle Miocene epoch and subsequently diverged into the current cryptic species in the Plio‐Pleistocene. A eurythermal common ancestor may have evolved independently in each region due to geographical events and paleoclimatic fluctuations, which made it possible for L. fasciatus complex to be an anti‐equatorial species. Despite their deep genetic divergence, they showed marked phenotypic similarity, suggesting that they have experienced similar selective pressures related to their specific behavior. [ABSTRACT FROM AUTHOR]

The Hawaiian sandburrowers Crystallodytes cookei and Limnichthys nitidus were found to be protandrous hermaphrodites based on a histological examination of gonad morphology and development. The majority of individuals of both species (71% and 75%, respectively) had delimited ovotestes in which ovarian and testicular tissue were divided by a connective tissue barrier. In juveniles and functional males, the ovarian and testicular regions were similar in cross-sectional area, whereas in functional females, the testicular portion was absent or greatly reduced. Reproductive females were significantly larger in body size than functional males but did not differ significantly in size with transitionals (individuals which contained both developing ova and visible spermatozoa). The complete absence of functional females at the smallest size ranges suggests that both species are monogynic; all females are derived from previously mature males. The ovotestis morphology and sequence of gonad development present in C. cookei and L. nitidus are most similar to protandrous porgies (family Sparidae). When compared to sex changing species of the closely related genus Trichonotus (family Trichonotidae), the distinct ovotestis morphology (delimited in creediids vs. mixed in Trichonotus) and differing direction of sex change (protandry vs. protogyny) suggest that sex change evolved independently in these taxa. [ABSTRACT FROM AUTHOR]

The regional occupancy and local abundance of species are affected by various species traits, but their relative effects are poorly understood. We studied the relationships between species traits and occupancy (i.e., proportion of sites occupied) or abundance (i.e., mean local abundance at occupied sites) of stream invertebrates using small-grained data (i.e., local stream sites) across a large spatial extent (i.e., three drainage basins). We found a significant, yet rather weak, linear relationship between occupancy and abundance. However, occupancy was strongly related to niche position ( NP), but it showed a weaker relationship with niche breadth ( NB). Abundance was at best weakly related to these explanatory niche-based variables. Biological traits, including feeding modes, habit traits, dispersal modes and body size classes, were generally less important in accounting for variation in occupancy and abundance. Our findings showed that the regional occupancy of stream invertebrate species is mostly related to niche characteristics, in particular, NP. However, the effects of NB on occupancy were affected by the measure itself. We conclude that niche characteristics determine the regional occupancy of species at relatively large spatial extents, suggesting that species distributions are determined by environmental variation among sites. [ABSTRACT FROM AUTHOR]

Primary burrowing crayfish make up 15% of total crayfish species, but account for 32% of those imperiled. Primary burrowers are also much less studied as compared to secondary and tertiary burrowers. The purpose of this study was to observe the annual life cycles, and morphometric and morphological characteristics of two primary burrowing crayfish species: Cambarus (Lacunieambarus) diogenes Girard, 1852 and C. (Tubericambarus) polychromatus Thoma et al., 2005. Sampling occurred adjacent to two streams near Troy, AL, using hand excavation at one-month intervals from February 2011 to March 2012. A total of 195 C. diogenes (sex ratio = 1.3) and 194 C. polyehromatus (sex ratio = 0.85) were collected. For a given size, C. diogenes had a broader carapace than C. polyehromatus (p < 0.001 ), and males had larger chelae than females for both species (p = 0.01 and p = 0.001, respectively). Minimum carapace length at sexual maturity (smallest form I) was 32.7 mm for C. diogenes males, 41.2 mm for C. diogenes females, 27.4 mm for C. polychromatus males, and 32.2 for C. polychromatus females. The proportion of form I males for both species increased in summer and remained at an increased level through winter, though C. polychromatus males remained reproductively active longer than C. diogenes. Females of both species were reproductively active only in winter except for one form I C. polychromatus female. Four ovigerous C. diogenes and three ovigerous C. polychromatus were collected in March, and five young of the year of C. polychromatus were found in burrows in June, July, and September. [ABSTRACT FROM AUTHOR]

The natural history of Pygidianops amphioxus de Pinna and Kirovskyi (Neotropical Ichthyology 9:493–504, 2011 ), a highly specialized sand-dwelling catfish species, was studied based on underwater observations in a small forest stream in the central Amazon. Information on the feeding and reproductive biology was obtained by means of analyses of preserved specimens. These miniature catfishes remained buried in the sand at the bottom of the stream and were never observed swimming in open water. The catfish consumed small benthic invertebrates, particularly Chironomidae larvae and Harpacticoida copepods, which were most likely captured by suction feeding inside the sand banks. Pygidianops amphioxus displays sexual dimorphism in the shape of the urogenital papilla and in the body length, with adult females being relatively longer than males. Sexually mature females were found throughout the year and carried a small number of proportionally very large oocytes. A short duration (24 h) experiment conducted in aquaria revealed that these small catfishes exhibit the predominantly nocturnal habits typical of most Siluriformes. [ABSTRACT FROM AUTHOR]

We compared hydrological environments and macroinvertebrate communities in 1st- and 2nd- order streams between a deer-excluded catchment (EC) and a control catchment (CC) to test effects of deerinduced hillslope soil erosion and sedimentation on macroinvertebrates. Overland flow contribution to the streams was greater in CC than in EC, and substrate in 1st-order streams contained more fine sediment in CC than in EC, whereas fine sediment in substrate in 2nd-order streams was similar between catchments. Macroinvertebrate community structure in 2nd-order streams was similar between catchments, but community structure in 1st-order streams differed between catchments. In 2nd-order streams, grazer and predator taxa predominated in both catchments, whereas in 1st-order streams, a clinger taxon predominated in EC and a burrower taxon predominated in CC. Diversity of macroinvertebrates in 1st- order streams was 1.14× higher in EC than in CC. We suggest that effects of deer on macroinvertebrates were less apparent in 2nd- than in 1st-order streams because fine sediments did not accumulate in 2nd-order streams exposed to deer browsing. Our results suggest that effects of sediment addition caused by deer browsing depends on the hydrogeomorphic properties of headwater streams. [ABSTRACT FROM AUTHOR]

Ainscough, B.J., Breinholt, J.W., Robison, H.W. & Crandall, K.A. (2013). Molecular phylogenetics of the burrowing crayfish genus Fallicambarus (Decapoda: Cambaridae). - Zoologica Scripta, 42, 306-316. The crayfish genus Fallicambarus contains 19 species of primary burrowing freshwater crayfish divided into two distinct subgenera. We test current hypotheses of the phylogenetic relationships among species within the genus as well as the monophyly of the genus. Our study samples all 19 species for five gene regions (both nuclear and mitochondrial) to estimate a robust phylogenetic hypothesis for the genus. We show that the genus is not a monophyletic group. The subgenus Creaserinus does fall out as a monophyletic group, but distinct from the subgenus Fallicambarus. The subgenus Fallicambarus appears to be monophyletic with the exception of the species Procambarus (Tenuicambarus) tenuis, which falls in the midst of this subgenus suggesting that it might be better classified as a Fallicambarus species. We also show that the species Fallicambarus fodiens is a species complex with distinct evolutionary lineages that are regionalized to different geographic areas. [ABSTRACT FROM AUTHOR]

Densities of sandy beach organisms along coastlines often vary considerably even within small local scales. In order to understand the demographic basis of density variations in shore animals, we examined the population dynamics of the amphipod Haustorioides japonicus Kamihira, which is an ideal subject because it lacks a planktonic dispersal stage in its life history. Quantitative sampling at three adjacent sandy beaches along the Sea of Japan coast revealed that the spring density, i.e., the density of overwintered individuals, was similar among the three beaches. However, the amount of recruitment of newly hatched juveniles from late spring to summer greatly differed among the beaches, resulting in large spatial variations in the summer density. Cohort analyses revealed that at all beaches, young-of-the-year (YOY) individuals reproduced and then died, and that individuals which recruited in late summer overwintered. Moreover, growth, fecundity, and survival schedules of overwintered and YOY individuals were very similar among beaches. These observations suggest that the difference in recruitment success, i.e., the survival of newly hatched juveniles, is the primary cause of the inter-population variation in the summer density. It is likely that variations in salinity and sandy sediment affect the recruitment success of newly hatched individuals. This study indicates that biological productivity may differ substantially even among adjacent sandy beaches, with important implications for beach management. [ABSTRACT FROM AUTHOR]

Abstract: Anguilliform or eel-like fishes are typically bottom dwellers, some of which are specialized burrowers. Although specializations for burrowing are predicted to affect the kinematics of swimming, it remains unknown to what extent this is actually the case. Here we examine swimming kinematics and efficiency of two burrowing anguilliform species, Pisodonophis boro and Heteroconger hassi, with different degrees of specialization for burrowing. Our data suggest that differences in the swimming kinematics may indeed be related to the differences in burrowing specialization and style between both species. The resemblance between the swimming kinematics of P. boro and previously published data for Anguilla anguilla and Anguilla rostrata may be linked with the relatively limited burrowing specialization of P. boro and suggests an overall stereotypy in anguilliform forward-swimming patterns. The body of H. hassi, in contrast, is more specialized for tail-first burrowing and backward swimming bears a striking resemblance to the backward burrowing motions observed in this species. These motions differ significantly from backward swimming in Anguilla and in P. boro. The kinematics of forward swimming are, however, comparable across species. Thus, our data suggest that specializations for burrowing may affect swimming kinematics in anguilliform fishes, but also that forward swimming and burrowing are not necessarily incompatible. Future studies comparing the kinematics and mechanics of burrowing in these and other anguilliform fishes are needed to better understand how specializations for burrowing constrain backward swimming in H. hassi. [Copyright &y& Elsevier]

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A specimen of Champsodon vorax Günther, 1867, of 113 mm SL, was caught on 6 September 2014 with a bottom trawl from the entrance of the Bay of Izmir, north-eastern Aegean Sea at a depth of 65 m. The presently reported study constitutes the fi rst record for the Aegean Sea but also the fourth record for the Mediterranean Sea. The specimen described in this paper is the largest individual reported to date from the Mediterranean. As it is evident from the spatial dynamics of all successive records of C. vorax in the Mediterranean this gaper seems to be a rapidly expanding species. It disperses both westwards and northwards. [ABSTRACT FROM AUTHOR]

A taxonomic review of Japanese species of the creediid genus Limnichthys recognised the following: L. fasciatus, L. nitidus (a senior synonym of L. donaldsoni) and L. orientalis sp. nov. L. fasciatus has an antitropical distribution. L. orientalis sp. nov. differs from its most similar congener, L. nitidus, in having fewer scales above and below the lateral line (2 vs. 3) and the fifth pelvic fin ray shorter or absent, and in the shape of cirri on the lower jaw. [ABSTRACT FROM AUTHOR]

The Indo West Pacific nakedband gaper, Champsodon nudivittis, is recorded for the first time from Israel on the basis of a single specimen collected off Ashdod, southern Israel. This species was previously recorded in the Mediterranean from eastern Turkey. Examination of Champsodon specimens deposited in the National Collection at Tel Aviv University revealed the previously unknown presence of C. nudivittis in the Red Sea. This presence suggests the species may have entered the Mediterranean through the Suez Canal. [ABSTRACT FROM AUTHOR]

The article presents a study of documentation of gaper (Champsodon capensis) from the Mediterranean Sea. It states that 24 species were gathered in Iskenderun Bay, Turkey by commercial fishing vessels with the use of bottom trawls. It mentions features of the Champsodon capensis including large head and mouth, no scales in the chin and with melanophores in the pelvic fin and pectoral fins.