Taxonomic differences and ecological conditionality of scale structure in three morphologically similar species of Far Eastern redfins of the genus <Emphasis Type="Italic">Tribolodon</Emphasis> (Teleostei: Cyprinidae)

Using the example of three morphologically similar species of the Far Eastern redfins of the genus Tribolodon, it has been shown that an analysis of scale structure allows species identification of not only adults, when they are not in their characteristic spawning dress, but also immature individuals. The most distinct interspecies differences of redfins have been found in the case of the combined use of three basic parameters of scales: lesser diameter, greater diameter, and number of radii. The differences between redfins in the shape and structure of their scales can be explained by the features of ecology of these species, e.g. the velocity of water flow in the breeding grounds and during overwintering in rivers.     

A new species of the grenadier genus <Emphasis Type="Italic">Coelorinchus</Emphasis> (Actinopterygii: Gadiformes: Macrouridae) from the Timor Sea,Eastern Indian Ocean

Coelorinchus okamurai sp. nov. is described from five specimens collected in the Timor Sea at a depth of 610–690 m. The new species belongs to the Coelorinchus japonicus group (redefined in this study), and differs from all other congeners in having the following combination of features: snout moderately long, sharply pointed in lateral and dorsal views, length 39–42% of head length; lateral nasal ridge completely supported by nasal bone; light organ short, length less than 1/2 orbit diameter, its anterior margin falling far short of pelvic-fin bases; premaxillary teeth in short, uniformly wide band, with posterior end of the tooth band not reaching lateral corner of mouth; no teeth greatly enlarged; body scales covered with short, reclined, narrowly blade-like spinules in widely divergent rows; buttresses of body scale spinules scarcely developed; occipital scales between parietal ridges armed with divergent rows of long, erect, needle-like spinules; nasal fossa usually naked (a few small scales rarely present anteroventrally); patches of small scales sparsely distributed on ventral surface of head; scales on underside of head armed with 1–3 rows of short, erect, needle-like to knife-like spinules; interdorsal space longer than first dorsal-fin base length; subopercle terminating as a long, slender flap; body dark overall without prominent markings; fins uniformly blackish.     

Descriptions of Four New Species of Criconematoidea (Tylenchina: Nemata) from Southern Chile

Four new species of Criconematoidea are described from Hoste Island, Chile. Criconema certesi n. sp. is distinguished by the fine, spine-like, cuticular extensions on body annuli; projection of annuli into rows of scales on posterior part of body; single, smooth, labial annulus set off by short collar from second (first body) annulus which is about same diameter as first (labial) annulus. Male with prominent caudal alae, slender curved spicules, and four incisures in lateral field. Ogma terrestris n. sp. is distinguished by small scales with rounded tips bearing minute, short bristles; scales number 21 at mid-body; and first (labial) annulus rounded, not retrorse, not set off from succeeding annuli, narrower in diameter from second (first body) annulus. Hemicycliophora macrodorata n. sp. is distinguished by its large size (L = 1.52 [1.28-1.72] mm); large stylet (146 [127-161] μm); annuli = 297 (280-315); tail slightly spicate, lateral field with or without interruptions of incisures, occasional anastomoses; and males with U-shaped spicules. Paratylenchus fueguensis n. sp. is distinguished by its prominent stylet with large, rounded knobs (4-5 μm across); cephalic region rounded not at all set off; lateral field with four incisures; lateral vulvar membranes present; and male tail short, strongly curved (almost 180°) ventrad.     

Comparative morphological analysis of big-scaled redfin <Emphasis Type="Italic">Tribolodon hakonensis</Emphasis> Günther, 1877 (Cyprinidae,Cypriniformes) from Sakhalin and southern Primorye

Comparative analysis of plastic and meristic characteristics of big-scaled redfin Tribolodon hakonensis from Sakhalin and southern Primorye has been performed. The considerable differences revealed are supported by results of genetic studies. The results of comparison of morphology of big-scaled and Pacific T. brandtii redfins with the purpose of assessing the probability of the previously advanced hypothesis on the origin of the “southern” form of big-scaled redfin are provided.     

Phylogeographic analysis reveals two periods of divergence in large-scaled redfin <Emphasis Type="Italic">Tribolodon hakonensis</Emphasis> (Pisces,Cyprinidae)

Analysis of mtDNA variation in one of the amphidromic Far Eastern redfins, Tribolodon hakonensis, revealed the presence of three considerably genetically different mtDNA phylogroups in the individuals from the Russian part of the range. These data suggest the presence of the two periods of divergent evolution in the history of the species examined. Comparison of the haplotype distributions from different phylogroups over the species range revealed geographic localization of only one phylogroup in the population samples from southern continental coastal regions of the Sea of Japan. At the same time, two other phylogroups were found in almost equal ratios in northern continental samples and near the Sakhalin Island. These results suggest that the first stage of the divergent evolution, which occured between Pliocene and Pleistocene, resulted in the formation of genetically isolated form (probably, a species) in the region of the Sea of Japan. The second, later period of divergence, probably associated with the separation of the Sea of Okhotsk from the Pacific Ocean then ended with the integration of earlier genetically separated forms into one species with the common gene pool.     

Swimming with the giant: coexistence patterns of a new redfin minnow Pseudobarbus skeltoni from a global biodiversity hot spot

Ecological niche theory predicts that coexistence is facilitated by resource partitioning mechanisms that are influenced by abiotic and biotic interactions. Alternative hypotheses suggest that under certain conditions, species may become phenotypically similar and functionally equivalent, which invokes the possibility of other mechanisms, such as habitat filtering processes. To test these hypotheses, we examined the coexistence of the giant redfin Pseudobarbus skeltoni, a newly described freshwater fish, together with its congener Pseudobabus burchelli and an anabantid Sandelia capensis by assessing their scenopoetic and bionomic patterns. We found high habitat and isotope niche overlaps between the two redfins, rendering niche partitioning a less plausible sole mechanism that drives their coexistence. By comparison, environment–trait relationships revealed differences in species–environment relationships, making habitat filtering and functional equivalence less likely alternatives. Based on P. skeltoni's high habitat niche overlap with other species, and its large isotope niche width, we inferred the likelihood of differential resource utilization at trophic level as an alternative mechanism that distinguished it from its congener. In comparison, its congener P. burchelli appeared to have a relatively small trophic niche, suggesting that its trophic niche was more conserved despite being the most abundant species. By contrast, S. capensis was distinguished by occupying a higher trophic position and by having a trophic niche that had a low probability of overlapping onto those of redfins. Therefore, trophic niche partitioning appeared to influence the coexistence between S. capensis and redfins. This study suggests that coexistence of these fishes appears to be promoted by their differences in niche adaptation mechanisms that are probably shaped by historic evolutionary and ecological processes.     

Johnius (Johnius) laevis,a new sciaenid from northern Australia and Papua New Guinea

A new sciaenid,Johnius (Johnius) laevis, is described from northern Australia and Papua New Guinea. Amongst theJohnius (Johnius) species with no mental barbel, ctenoid body scales, and more than 10 lower gill rakers, the new species is distinguished by the combination of the following characters: dorsal soft rays 29–34; scales above the lateral line 5–6, and below 8–10; eye diameter 22.4–30% HL; interorbital width 24.6–29.8% HL; and body scales with weakly developed ctenii.     

Three new freshwater species of centrohelid heliozoans: Acanthocystis crescenta sp. nov., A. kirilli sp. nov., and Choanocystis minima sp. nov.

Three new species of centrohelid heliozoans Acanthocystis crescenta, A. kirilli, and Choanocystis minima from two freshwater lakes of Valamo Island (North-Western Russia) were studied using light- and scanning electron microscopy. The main apomorphy of A. kirilli are slightly branched radial scales. Acanthocystis crescenta has characteristic radial scales with crescent-like structures on their tips. Cell diameter of these two species does not exceed 10 μm. Radial scales of C. minima have truncated tips and lack apical teeth; plate scales of this species are oviform, without lateral notches or central rib. The latter organism is the smallest heliozoan species known; the diameter of its body is about 3 μm. The possible domination of small heliozoans in the cryptic diversity of centrohelids is discussed.     

Two New Species of Goby of the Genus <Emphasis Type="Italic">Astrabe</Emphasis> from Japan

Two species of goby belonging to the genus Astrabe are described from Japan as new species, A. flavimaculata and A. fasciata. A. flavimaculata is distinguishable from A. lactisella, the type species and hitherto the only known species of the genus, in that it has no protrusion on the upper posterior part of the dermal fold along the upper margin of the eye, fewer scales in a longitudinal row, predorsal scales, scales on the belly, a narrower white transverse band across the base of the pectoral fins, and in life yellow markings on a dark brown ground colour except for the white transverse band across the base of the pectoral fins. A. fasciata is distinguishable from A. lactisella in that it has fewer scales in a transverse row, a narrower scaled area on the lateral side of the body, a narrower white transverse band across the base of the pectoral fins, and a white transverse band across the anterior part of the 1st dorsal fin extending to the ventral side of the body.     

Two sympatric new species of woodlizards (Hoplocercinae, Enyalioides) from Cordillera Azul National Park in northeastern Peru

We report the discovery of two sympatric new species of Enyalioides from a montane rainforest of the Río Huallaga basin in northeastern Peru. Among other characters, the first new species is distinguishable from other Enyalioides by the combination of the following characters: strongly keeled ventral scales, more than 37 longitudinal rows of dorsals in a transverse line between the dorsolateral crests at midbody, low vertebral crest on the neck with vertebrals on neck similar in size to those between hind limbs, projecting scales on body or limbs absent, 96 mm maximum SVL in both sexes, and caudals increasing in size posteriorly within each autotomic segment. The second new species differs from other species of Enyalioides in having strongly keeled ventral scales, scales posterior to the superciliaries forming a longitudinal row of strongly projecting scales across the lateral edge of the skull roof in adults of both sexes, 31 or fewer longitudinal rows of strongly keeled dorsals in a transverse line between the dorsolateral crests at midbody, vertebrals on neck more than five times the size of vertebrals between hind limbs in adult males, projecting scales on body or limbs absent, and caudals increasing in size posteriorly within each autotomic segment. We also present an updated molecular phylogenetic tree of hoplocercines including new samples of Enyalioides rudolfarndti, Enyalioides rubrigularis, both species described in this paper, as well as an updated identification key for species of Hoplocercinae.     

Ontogenetic scaling of scansorial surface area and setal dimensions of Chondrodactylus bibronii (Gekkota: Gekkonidae): testing predictions derived from cross‐species comparisons of gekkotans

Little is known of how the adhesive apparatus of gekkotans scales with growth. Cross‐species comparisons of certain characteristics, using size as a comparator to investigate scaling relationships, suggest certain relationships between subdigital pad area and body size. The manner in which the adhesive apparatus grows and scales within any one species, however, remains unknown, and it is unclear whether interspecific and intraspecific patterns are similar. To address this, we examined a post‐hatching ontogenetic series of the southern African gecko Chondrodactylus bibronii and demonstrate that setal density, setal basal diameter and setal spacing remain relatively constant in relation to size, indicating conserved subdigital pad assembly rules that are independent of size. Conversely, however, average and maximal setal lengths increase slightly and isometrically with size, an outcome that is probably explained by setal row recruitment, and the surface area of the subdigital pads scales close to, but below, isometry with respect to body mass and snout–vent length, it therefore does not increase sufficiently with size to compensate for the increase in mass. As a result, relative adhesive capacity decreases with growth with a regression slope of –0.45.     

Conservative whole‐organ scaling contrasts with highly labile suborgan scaling differences among compound eyes of closely related Formica ants

Static allometries determine how organ size scales in relation to body mass. The extent to which these allometric relationships are free to evolve, and how they differ among closely related species, has been debated extensively and remains unclear; changes in intercept appear common, but changes in slope are far rarer. Here, we compare the scaling relationships that govern the structure of compound eyes of four closely related ant species from the genus Formica. Comparison among these species revealed changes in intercept but not slope in the allometric scaling relationships governing eye area, facet number, and mean facet diameter. Moreover, the scaling between facet diameter and number was conserved across all four species. In contrast, facet diameters from distinct regions of the compound eye differed in both intercept and slope within a single species and when comparing homologous regions among species. Thus, even when species are conservative in the scaling of whole organs, they can differ substantially in regional scaling within organs. This, at least partly, explains how species can produce organs that adhere to genus wide scaling relationships while still being able to invest differentially in particular regions of organs to produce specific features that match their ecology.     

Some Features of the Environmental Strategy of <Emphasis Type="Italic">Tulipa gesneriana</Emphasis> L. (Liliaceae,Liliopsida)

The vitality of 31 natural populations of Tulipa gesneriana is based on our field surveys that were conducted in several parts of European Russia from 2013 to 2015. The basic factors that affect the vitality of the T. gesneriana population were revealed according to the results of the analysis of 14 morphological parameters of T. gesneriana. Cattle grazing was the most essential factor. The effect of other negative factors is much lower. On the whole, the mixed stress-tolerant and ruderal ecological cenotic strategy is characteristic of the species. For instance, an increase in the stress level leads to a decrease in the size of all aboveground organs, which is accompanied by considerable variations in the height and diameter of plants. However, most of the parameters, on the contrary, have a weak reduction in their variability under stress. All these features indicate a comparatively narrow ecological amplitude of the species investigated.     

Effect of sex and age on structural features of nasal calls and body size in fawns of the goitered gazelle, <Emphasis Type="Italic">Gazella subgutturosa</Emphasis> (Artiodactyla,Bovidae)

Male goitered gazelles differ from conspecific females in having a highly prominent larynx. However, the development of sex dimorphism in the vocal apparatus and the structure of calls has not yet been studied in this species. This study deals with structural changes in the acoustic parameters of nasal calls and the body size of goitered gazelle fawns in the course of ontogeny, from birth to 6 months of age. It has been shown that their body weight and neck girth linearly increase with age, while the basic frequency of nasal calls decreases gradually; however, age-related changes in the duration and power parameters of nasal calls are nonlinear. Their basic frequency (94 Hz in males and 118 Hz in females at the age of 2 weeks) is significantly lower than in juveniles of any other ungulate species of comparable size. In fawns of any age group, the index of sexual dimorphism in the basic frequency of nasal calls is at least twice that in the body weight or neck girth, indicating that laryngeal hypertrophy in males is already developed at birth. On the other hand, this index does not increase until the fawns are 6 months old, which is evidence that the accelerated growth of male larynx apparently starts later, in the pubertal period, under the effect of sex hormones.     

A new species of the genus <Emphasis Type="Italic">Balitora</Emphasis> (Teleostei: Balitoridae) from Guangxi,China

A new species of the hillstream loach genus Balitora Gray, Balitora ludongensis, from Qilong River which drains to Zuojiang River (a headwater of the Pearl River) drainage, Jingxi County, Guangxi, China. It can be distinguished from its congeners by the following characters: pectoral fin with vi–vii, 11–12 rays; pelvic fin with ii, 6–7 rays; pre-oral groove relatively shallow, upper lip without or with 3–5 fold-like papillae in a row on its middle surface and gradually smooth to the corner of mouth; two maxillary barbels at each corner of mouth, the outer one slightly longer than the inner one, 149.0–190.9% of eye diameter; eyes small, eye diameter 14.2–18.1% of head length; Dorsal-fin origin slightly anterior to pelvic-fin origin; Caudal-peduncle depth 39.1–55.0% of its length; upper lobe of caudal fin longer than the lower one; lateral-line scales 69–74; with 6–9 black blotches on the dorsal side of body.     

Patterns of co‐occurrences in a killifish metacommunity are more related with body size than with species identity

Body size may be more important than species identity in determining species interactions and community structure. However, co‐occurrence of organisms has commonly been analysed from a taxonomic perspective and the body size is rarely taken into account. On six sampling occasions, we analysed patterns of killifish co‐occurrences in nestedness (tendency for less rich communities to be subsamples of the richest), checkerboard structure (tendency for species segregation), and modularity (tendency for groups to co‐occur more frequently than random expectation) in a pond metacommunity located in Uruguay. We contrasted co‐occurrence patterns among species and body size‐classes (individuals from different species were combined into size categories). The analysis was performed at two spatial scales: ponds (communities) and sample units within ponds. Observed nestedness was frequently smaller than the null expectation, with significantly greater deviations for body size‐classes than for species, and for sample units than for communities. At the sample unit level, individuals tended to segregate (i.e. clump into a checkerboard pattern) to a larger extent by body size rather than by taxonomy. Modularity was rarely detected, but nevertheless indicated a level of taxonomic organization not evident in nestedness or checkerboard indices. Identification of the spatial scale and organization at which ecological forces determine community structure is a basic requirement for advancement of robust theory. In our study system, these ecological forces probably structured the community by body sizes of interacting organisms rather than by species identities.     

四川55种鱼生活史型的研究

四川５５种鱼生活史型的研究刁晓明,罗一兵李波（西南农业大学水产系,重庆６３０７１６）（重庆大学计算机系,６３００００）ＬｉｆｅＨｉｓｔｏｒｙＰａｔｔｅｒｎｓｏｆ５５ＦｉｓｈＳｐｅｃｉｅｓｉｎＳｉｃｈｕａｎ￥ＤｉａｏＸｉａｏｍｉｎｇ;ＬｕｏＹｉｂｉｎｇ...     

New deepwater species of the genus <Emphasis Type="Italic">Gobiopsis</Emphasis> (Gobiidae) from the Tropical Western Pacific

A new species, Gobiopsis uranophilus sp. n., is described off the Anambas Islands, South China Sea, from a depth of 73 m. The species is similar to the deepwater Japanese species G. namnas, but it differs in the dorsal orientation of the eyes, total absence of pores of the seismosensory system on the head, number of fin rays, and other characters. The similar patterns of the two species (presence of scales on the sides of the head, absence of the barbel-shaped appendages on the head, and large scales on the body), most likely, are connected with their adaptation to deepwater habitats.     

Squamatological differences between two closely related flatfish species of the genus <Emphasis Type="Italic">Pleuronichthys</Emphasis> (Pleuronectidae,Pleuronectiformes), with a proposal of unambiguous distinctive characters

Squamation and scale morphology were examined in two closely related species, Pleuronichthys cornutus and P. japonicus, in order to establish the unambiguous characters to clearly separate the two species. Scale counts on the lateral body surface were also examined, with new count definitions proposed. Both the longitudinal and vertical scale rows followed essentially regular patterns in P. cornutus, whereas the longitudinal scale rows were occasionally irregular in P. japonicus. Scales were basically fan-shaped and oval in P. cornutus and P. japonicus, respectively, although considerable variation in scale shape was apparent in both species. The blind side scales of P. cornutus had sharp posterior margins, whereas those of P. japonicus had round ones. Scale length (scales on the ocular side, area above the lateral line) in P. japonicus was relatively greater than in P. cornutus, a plot of total length versus scale length separating the species completely. Measurements of many ocular side scales from the area above the lateral line indicated high intraspecific variance in both species, being particularly prominent in P. cornutus. Nevertheless, considerable scale measurement differences were found between the two species in some body areas, supported by principal component analysis. Longitudinal and vertical row scale counts were higher in P. cornutus than in P. japonicus, with the ranges of central longitudinal scales (88–103 vs. 75–86) and scales below the lateral line counts (59–74 vs. 47–57), respectively, not overlapping between the species. The scale count difference could be caused by the difference of the scale size between the two species. The study demonstrated that the two Pleuronichthys species can be readily distinguished on the basis of scale morphology and size, in addition to scale counts.