BarredDanio species from the Irrawaddy River drainage (Teleostei, Cyprinidae)

The three barredDanio species known from the Irrawaddy River drainage are redescribed. Two species are known from southwestern Yunnan:Danio interruptus in the Husa He and Longchuan, Jian watersheds, andD. apogon abundantly in the main river and tributaries of the Daying Jiang basin. The third species,D. shanensis, occurs in the Myitnge basin of northern Shan State, Myanmar.Danio interruptus differs from other barredDanio species by having a short, incomplete lateral line, a deeper head, and shorter thicker dark vertical bars or blotches anteriorly on the sides.Danio shanensis has the lateral line either complete or incomplete, lesser head depth, and a series of deeper narrower vertical bars.Danio apogon has no lateral line, narrow or indistinct dark vertical bars, and a wide, but indistinct, horizonatal P stripe.Danio choprae, previously considered, as a barredDanio species, is more closely related to theD. dangila species group.     

Oxynoemacheilus cemali,a new species of stone loach (Teleostei: Nemacheilidae) from the Çoruh River drainage,Turkey

Oxynoemacheilus cemali sp. nov. is described from the Çoruh River drainage in the eastern Black Sea basin. One molecular marker (coI), 25 morphometric and four meristic characters were analysed. Oxynoemacheilus cemali is distinguished from O. kosswigi, O. banarescui, O. samanticus and O. angorae in the Black Sea basin by having a suborbital groove in males, an axillary lobe at the pelvic-fin base, no dorsal adipose crest on the caudal peduncle, a slightly-forked caudal fin and 7–15 dark grey dorsal saddles. Morever, Oxynoemacheilus cemali is distinguished by commonly having 9–15 irregularly-shaped dark-grey bars on the flank posterior to the dorsal-fin origin or, rarely having a mottled pattern or 4–6 irregularly shaped dark-grey bars on the flank posterior to the dorsal-fin origin. Oxynoemacheilus cemali is also distinguished from the closely related species O. araxensis and O. cyri, distributed outside the Black Sea basin, by having 15 and 31 diagnostic nucleotide substitutions in the coI barcode region, respectively.     

Scale morphology and flexibility in the shortfin mako Isurus oxyrinchus and the blacktip shark Carcharhinus limbatus

We quantified placoid scale morphology and flexibility in the shortfin mako Isurus oxyrinchus and the blacktip shark Carcharhinus limbatus. The shortfin mako shark has shorter scales than the blacktip shark. The majority of the shortfin mako shark scales have three longitudinal riblets with narrow spacing and shallow grooves. In comparison, the blacktip shark scales have five to seven longitudinal riblets with wider spacing and deeper grooves. Manual manipulation of the scales at 16 regions on the body and fins revealed a range of scale flexibility, from regions of nonerectable scales such as on the leading edge of the fins to highly erectable scales along the flank of the shortfin mako shark body. The flank scales of the shortfin mako shark can be erected to a greater angle than the flank scales of the blacktip shark. The shortfin mako shark has a region of highly flexible scales on the lateral flank that can be erected to at least 50°. The scales of the two species are anchored in the stratum laxum of the dermis. The attachment fibers of the scales in both species appear to be almost exclusively collagen, with elastin fibers visible in the stratum laxum of both species. The most erectable scales of the shortfin mako shark have long crowns and relatively short bases that are wider than long. The combination of a long crown length to short base length facilitates pivoting of the scales. Erection of flank scales and resulting drag reduction is hypothesized to be passively driven by localized flow patterns over the skin. J. Morphol. 2012. © 2012 Wiley Periodicals, Inc.     

<Emphasis Type="Italic">Paracobitis nanpanjiangensis,</Emphasis> a new loach (Balitoridae: Nemacheilinae) from Yunnan,China

A new species of the genus Paracobitis, Paracobitis nanpanjiangensis is described from tributaries of the Nanpanjiang River drainage in China. It is distinguished from its congeners, except P. oligolepis and P. wujiangensis, by body scaleless or with rudimentary scales (caudal peduncle with several deeply embedded scales). It can be differentiated from P. wujiangensis by the complete lateral line (vs. incomplete), lower dorsal crest reaching the vertical of origin of anal fin (vs. shorter and higher dorsal crest not reaching the base of anal fin). It is distinguished from P. oligolepis by the following characters: branched dorsal fin with 81/2 (a few 91/2) rays (vs. 91/2), interspaces between bars in front of dorsal fin conspicuously thinner than those behind (vs. vermiform markings), dorsal head without vermiform markings or obscure (vs. clearly vermiform markings on dorsal head), vertebrae 4 + 36–38 (vs. 4 + 39–41).     

<Emphasis Type="Italic">Erromyzon damingshanensis</Emphasis>, a new sucker loach (Teleostei: Cypriniformes: Gastromyzontidae) from the Pearl River drainage of Guangxi,China

Erromyzon damingshanensis, a new sucker loach is described from the Pearl River drainage in Guangxi, China. The new species Erromyzon damingshanensis is distinguished from the other species of the genus in having a crescentic median lobe of the rostral fold, rostral barbels shorter than rostral fold; postlabial groove broadly interrupted medially, seven branched dorsal fin rays, 16 branched pectoral fin rays, lateral line scales 88–95, caudal peduncle depth larger than its length; body with 12 irregular bars on flank, interrupted on dorsum.     

围封年限对内蒙古灌丛化草原小叶锦鸡儿灌丛结构及群落种间关联的影响

由于全球气候变化及过度放牧等不合理利用,灌木入侵草地已经成为干旱半干旱草原区的一种普遍现象。本研究在内蒙古锡林郭勒草原区选择3处不同围封恢复年限（围封时间分别为1979,1983和2003年）的小叶锦鸡儿（Caragana microphylla）灌丛化草地,分析了围封年限对灌丛化草地关键种小叶锦鸡儿种群大小格局及灌丛间主要物种种间关联的影响,并从群落内物种生态位配置情况方面进行了相关机制的探讨。结果显示：（1）小叶锦鸡儿的冠幅大小分布结构的偏态系数在8/9的样区内大于0,表现为正偏态;随着围封年限的延长,在低、中灌丛化样区内,小叶锦鸡儿的冠幅有增大的趋势,这主要是由小于0.5 m冠幅的小叶锦鸡儿的减少或者消失导致的;（2）随着围封年限的延长,灌丛间多年生禾草生态位宽度（B）逐渐增大,表现为B_1979围封 > B_1983围封 > B_2003围封;灌丛间主要物种种间关系由负关联作用（竞争作用）向正关联作用（促进作用）转变。本研究结果不仅揭示了围封条件下小叶锦鸡儿灌丛化草地群落结构的变化及发展趋势,同时也从关键种小叶锦鸡儿种群大小格局及灌丛间主要物种种间关联的角度对相关机制进行了解释,为该区域的合理利用及恢复政策的制定提供了数据支持及理论指导。     

近岸典型生态系统大型底栖动物的次级生产力——以瓯江口、洞头列岛为例

为更好了解和估算河口及岛屿生态系统大型底栖动物次级生产力的情况,以近岸两个典型生态系统河口-瓯江口、岛屿-洞头列岛为例,于2015年4月和10月在该海域进行大型底栖动物调查,采用3种Brey经验模型对大型底栖动物次级生产力进行估算,并分析次级生产力与环境因子的关系。结果表明:(1)以去灰干重(ash-free dry weight,AFDW)计,Brey经验公式估算瓯江口和洞头列岛海域年均次级生产力分别为0.48 g(AFDW)m~(-2)a~(-1)和0.70 g(AFDW)m~(-2)a~(-1),Brey模型估算瓯江口和洞头列岛海域年均次级生产力分别为0.51 g(AFDW)m~(-2)a~(-1)和1.55 g(AFDW)m~(-2)a~(-1),Brey模型估算瓯江口和洞头列岛海域年均次级生产力分别为0.25 g(AFDW)m~(-2)a~(-1)和0.99 g(AFDW)m~(-2)a~(-1)。(2)3种经验模型反映大型底栖动物年均次级生产力空间分布趋势一致:瓯江口海域有1高值区,位于瓯江口南部;洞头列岛海域有2高值区,分别位于洞头本岛东北部的三盘岛与花岗岛之间和东黄岛东南部的岛屿之间。(3)瓯江口海域大型底栖动物年均次级生产力主要贡献种为双鳃内卷齿蚕Aglaophamus dibranchis、长吻沙蚕Glycera chirori、异蚓虫Heteromastus filiforms、焦河篮蛤Potamocorbula ustulata、薄云母蛤Yoldia similis、圆筒原盒螺Eocylichna braunsi,它们对次级生产力的贡献率超54.2%;洞头列岛海域大型底栖动物年均次级生产力主要贡献种为双鳃内卷齿蚕、异蚓虫、薄云母蛤、绒毛细足蟹Raphidopus ciliatus、隆线强蟹Eucrate crenata、脑纽虫Cerebratulina sp.、红狼牙鰕虎鱼Odontamblyopus rubicundus,它们对次级生产力的贡献率超57.1%。(4)次级生产力与环境因子的相关性分析显示化学需氧量、悬浮物和表层沉积物中值粒径是影响瓯江口海域大型底栖动物年均次级生产力的重要环境因子,而环境因子与洞头列岛海域大型底栖动物年均次级生产力相关关系不显著。(5)瓯江口海域Brey经验公式与Brey模型估算结果基本一致,洞头列岛海域Brey经验公式与Brey模型估算结果基本一致。     

A new species of trout from the northern drainages of Euphrates River,Turkey (Salmoniformes: Salmonidae)

Salmo fahrettini, a new species, is distributed in the northern tributaries of the Euphrates River. It differs from other Salmo species in adjacent waters by a combination of the following characters: a greyish body; one black spot behind the eye and on the cheek; three to six black spots on the opercle; numerous black spots on the back (missing on the predorsal area), flank and middle part of body, surrounded by a roundish white ring; red spots in the median part of the body, surrounded by a roundish white ring; short and narrow maxilla; increase in the number of black and red spots with an increase in size; adipose fin medium size, no or rarely one red spot at its posterior edge; 109–116 lateral line scales; 27–30 scale rows between dorsal-fin origin and lateral line; 20–23 scale rows between the lateral line and anal-fin origin; maxilla length 8.8–10.0% standard length in males, 8.8–9.6 in females.     

Listera fugongensis (Orchidaceae), a new species from Yunnan, China

Listera fugongensis, a new species from Yunnan, China, is described and illustrated. The new species is probably related to Listera nipponica, but differs from it by having green flowers, petals slightly wider than lateral sepals, and a toothed lip with ciliate margins.     

Evolution and diversification of a sexually dimorphic luminescent system in ponyfishes (Teleostei: Leiognathidae), including diagnoses for two new genera

A phylogeny was generated for Leiognathidae, an assemblage of bioluminescent, Indo‐Pacific schooling fishes, using 6175 characters derived from seven mitochondrial genes (16S, COI, ND4, ND5, tRNA‐His, tRNA‐Ser, tRNA‐Leu), two nuclear genes (28S, histone H3), and 15 morphological transformations corresponding to features of the fishes' sexually dimorphic light‐organ system (LOS; e.g., circumesophageal light organ, lateral lining of the gas bladder, transparent flank and opercular patches). Leiognathidae comprises three genera, Gazza, Leiognathus, and Secutor. Our results demonstrate that Leiognathidae, Gazza, and Secutor are monophyletic, whereas Leiognathus is not. The recovered pattern of relationships reveals that a structurally complex, strongly sexually dimorphic and highly variable species‐specific light organ is derived from a comparatively simple non‐dimorphic structure, and that evolution of other sexually dimorphic internal and external features of the male LOS are closely linked with these light‐organ modifications. Our results demonstrate the utility of LOS features, both for recovering phylogeny and resolving taxonomic issues in a clade whose members otherwise exhibit little morphological variation. We diagnose two new leiognathid genera, Photopectoralis and Photoplagios, on the basis of these apomorphic LOS features and also present derived features of the LOS to diagnose several additional leiognathid clades, including Gazza and Secutor. Furthermore, we show that five distinct and highly specialized morphologies for male‐specific lateral luminescence signaling, which exhibit species‐specific variation in structure, have evolved in these otherwise outwardly conservative fishes. Leiognathids inhabit turbid coastal waters with poor visibility and are often captured in mixed assemblages of several species. We hypothesize that the species‐specific, sexually dimorphic internal and external modifications of the leiognathid LOS provide compelling evidence for an assortative mating scheme in which males use species‐specific patterns of lateral luminescence signaling to attract mates, and that this system functions to maintain reproductive isolation in these turbid coastal environments. © The Willi Hennig Society 2005.     

Scale morphological variation across the flank in four Tonguefishes species collected from the Gulf of Oman (Pleuronectiforms; Cynoglossidae)

The scale morphology of pleuronectiforms in the Gulf of Oman remains insufficiently known. This study used light microscopy and morphological analysis to examine scale variation across the flank of four Tonguefishes species; Cynoglossus arel, C. bilineatus, C. lingua, and C. puncticeps. Scales were extracted from six flank regions, three on the eyed and blind sides, respectively. The most differentiated species was C. arel, which showed significant differences in four size variables in five regions. In Cynoglossus arel and C. lingua, the scales of the eyed side were ctenoid, and those scales from the blind side were cycloid; C. puncticeps have ctenoid scales on both flank sides and C. bilineatus has cycloid scales on both sides. All species' scales on the blind side have fewer ctenial spines (except in C. bilineatus). This study indicated that scale morphology demonstrated considerable variation among the flank regions of the examined species. As a result, the scales from the head and the trunk regions of the eyed side and the scales from the head region of the blind side have a good power of species separation in this family.     

A new species of Characidium (Characiformes: Crenuchidae) from the rio Madeira basin,Brazil

This study describes Characidium nambiquara, a new species from the upper rio Guaporé, rio Madeira basin, Brazil. The new species differs from most congeners by the presence of isthmus and area between the contralateral pectoral-fin bases completely naked. From congeners with some degree of scaleless ventral surface of the body C. nambiquara differs by having 10 circumpeduncular scales. The new species is also distinguished from congeners by the spotted colour pattern on body of the large-sized specimens and by having black dashes on all fins and conspicuous midlateral longitudinal dark stripe or conspicuous vertical bars absent. Characidium nambiquara further differs from most congeners by the presence of 34–36 pored scales on the lateral line, 3 horizontal scale rows above the lateral line and 3 horizontal scale rows from the lateral line to the midventral scale series. Remarks on intraspecific colour variation within the genus, not related to sexual dimorphism, are also provided.     

Hemiodus bimaculatus,a new species of Hemiodontidae from the Rio Tapajós drainage,Brazil (Ostariophysi: Characiformes)

Hemiodus bimaculatus sp. nov., is described from tributaries of the Rio Juruena and Rio Teles Pires in the upper Rio Tapajós basin. The new species is diagnosed from most congeners, except Hemiodus jatuarana, by having a conspicuous circular or horizontally elongate dark blotch on the caudal peduncle (v. inconspicuous in H. iratapuru and absent in the other species). The new species differs from H. jatuarana by having a round midlateral spot on the flank (v. absent in H. jatuarana), 98–121 perforated scales in the lateral line (v. 66–72 in H. jatuarana), 23–28 scale series above and 14–19 below lateral line (v. 12–13 above and 6–7 below in H. jatuarana). Hemiodus bimaculatus is hypothesised to be related to species of the H. microlepis group, from which it also differs by having 11–25 epibranchial (v. 26–34 in H. argenteus, 29–39 in H. microlepis, 21–42 in H. orthonops and 27–35 in H. parnaguae) and 18–31 ceratobranchial (v. 38–50 in H. argenteus, 43–58 in H. microlepis, 32–52 in H. orthonops and 34–48 in H. parnaguae) gill rakers in the first arch.     

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

A new species, Pseudogyrinocheilus longisulcus, was discovered from a tributary of Pearl River in Jingxi Co., Guangxi, China, The new species can be distinguished from other species of Pseudogyrinocheilus by the following combination of characteristics: prolonged post-labial grooves, and extended antero-medially close to anterior end of middle lower lip, but not meeting with its counterpart; posterior margin of lower lip free; scales of abdomen from thorax to pectoral-fin base embedded under skin; lateral-line scales 40–42; dark stripe longitudinal along lateral line on flank. The key to the species of Pseudogyrinocheilus is provided.     

Group Recruitment and Early Survival of Mazzaella Laminarioides

Several phycocolloid-producing Rhodophyta of significant economic importance are coalescing species, able to fuse with conspecifics during recruitment, reach larger sizes and increase their survival. In these species spores are needed to start cultivation (e.g. Gigartina, Mazzaella) or to increase the seed stocks, to renew senescent clones or to enlarge the base of genetic variation of vegetatively propagated species (e.g. Chondrus, Gracilaria, Eucheuma). This study uses Mazzaella laminarioides to evaluate some key features that influence recruitment success. Field measurements indicate that in any recruitment event a variable amount of the spores reaching a given place may form groups of 2 to over 100 coalescing spores, while field experiments support the idea that early recruitment success is a function of the number of coalescing spores forming the individual, as multisporic, coalescing recruits have higher survival rates than sporelings formed by one or a few spores. Therefore, group recruitment (spores settling and recruiting in close spatial proximity) appears as a prerequisite for sporeling coalescence and early recruitment success. In turn, laboratory experiments suggest that the frequency of group recruitment and coalescence increases with increasing spore abundance and with slight Ca⁺⁺ additions to the culture medium. These last two factors could be handled by farmers to improve the success of spore inoculations of coalescing species.     

Barbus xanthos,a new barbel from the Southern Aegean basin (Teleostei: Cyprinidae)

Barbus xanthos, a new species, is described from the Eşen, Dalaman, Tersakan and Büyük Menderes rivers in south-western Anatolia. It differs from other Barbus species in the adjacent basins by having 53–60 lateral line scales, a weakly ossified last unbranched dorsal-fin ray (about 33–50%), numerous small irregular-shaped black or dark-brown spots smaller than scales, often forming large, black or dark-brown blotches on back and flank in juveniles and adults, and a straight or slightly convex posterior dorsal-fin margin. B. xanthos differs from its most closely related congener, B. pergamonensis, by nine nucleotide substitution sites in the mitochondrial DNA cytochrome oxidase I barcode region.     

A new species of Astyanax (Characiformes: Characidae) from Costa Rica and Panama,with a key to the lower Central American species of the genus

Astyanax anai, a new species of characid fish, is described from the Sixaola River basin, eastern Costa Rica–western Panama, Central America. The new species can be distinguished from all other congeners by the following combination of characters: premaxillary teeth 4–5 at the inner series and 4–6 at the outer series; maxillary teeth tricuspid, 2–4; predorsal scale series irregular and incomplete, with an unscaled space behind tip of supraoccipital process and 12–14 scales; lateral line scales 34–39; humeral region with a conspicuous black and rounded to horizontally ovate spot and two diffuse brown and vertically elongate bars (the first through the rounded to horizontally ovate spot, the second 2–4 scales behind the first); body depth 36·6–42·3% of standard length (L_S); midlateral stripe formed by a series of 10–14 anteriorly‐directed dermal herringbone, or chevron‐shaped, marks, most apparent in juveniles and in preserved specimens, extending above the lateral line from the black humeral spot or just behind it (from the second vertical bar) to the caudal peduncle; scale rows from lateral line to base of first dorsal‐fin ray 8–9; scale rows from lateral line to base of pelvic fin 7–8; pre‐anal distance 53·9–61·9% of L_S; total anal‐fin elements 29–33; caudal spot elongated, rhomboid or rectangular, with its anterior margin surpassing the middle of the caudal peduncle, usually reaching the anal‐fin insertion, posteriorly covering 4–7 principal caudal‐fin rays and not extending onto the ventral and dorsal margins of the caudal peduncle, covering 3–5 horizontal scale rows. In order to test the phylogenetic relationships of the new taxon in relation to the other North and Central American species of the genus, a new phylogenetic hypothesis based on a reanalysis of the morphological matrix by Schmitter‐Soto (2016) is proposed. A key to the lower Central American (southern Nicaragua to eastern Panama) species of Astyanax is also provided.     

Influence of Lateral Masking on Contrast Detection Thresholds of Bars Differing in Width

Contrast detection thresholds for bars 1, 2, or 3 arcmin wide and 1 deg long were estimated in the presence of high-contrast flank bars of the same size. The distance between the flank and the test bars varied from 1 to 30 arcmin. Regardless of the bar width, the thresholds increased when the test and flank bars were in a summation zone 6–8 arcmin wide. With increasing distance between the test and flank bars, the thresholds decreased and reached a plateau. The results testified to an influence of surrounding patterns on the responses of individual receptive fields of neurons processing the test stimuli rather than to lateral interactions between the fields. An attempt was made to apply this explanation to the results of earlier studies concerning the lateral interactions of spatial frequency channels in tasks consisting of detection of objects masked in the same manner.     

高寒草甸种间性状差异和物种均匀度对物种多样性与功能多样性关系的影响

物种多样性(SD)与功能多样性(FD)之间存在多种关系,但由于生态系统功能主要由物种的功能属性决定,因而功能多样性对生态系统功能的影响大于物种多样性的影响。但在种间性状差异和物种均匀度这两个构成功能多样性的基本成分中,何者对功能多样性影响更大,并进而决定SD-FD关系尚不明确。通过在高寒矮嵩草(Kobresia humilis)草甸为期6a的刈割(留茬1 cm、3 cm及不刈割)和施肥(尿素7.5 g m~(-2)a~(-1)+磷酸二胺1.8 g m~(-2)a~(-1)、不施肥)控制实验,研究了种间性状差异(33个物种13个性状)和物种均匀度(所有物种)对物种多样性(所有物种)与功能多样性(33个物种13个性状)之间关系的影响。研究结果显示:(1)物种多样性与功能多样性正相关,它们与多性状种间差异负相关,而与物种均匀度正相关。物种均匀度是导致功能多样性变化的主要因素,也是导致SD-FD正相关的原因,这是因为随着物种多样性增加,物种均匀度的增加程度大于多性状种间差异的减少程度,因而功能多样性增加,SD-FD正相关;(2)功能多样性指数(FD_(Rao)和FDis)随物种多样性指数(H')减速递增,表明群落存在一定的功能冗余,且功能冗余随物种多样性的增大而增大,但尚未达到产生SD-FD无相关性的极限H'值;(3)功能多样性对高寒草甸生态系统地上净初级生产力(ANPP)的影响大于物种多样性的影响,二元线性回归显示在同时考虑二者对ANPP的影响时,可排除物种多样性的作用。但由于物种多样性下降或物种丧失引起的物种功能性状丢失或性状空间维度减小将导致功能多样性降低,表明它们之间存在一定互补性,在研究生物多样性与生态系统功能关系时,同时考虑物种多样性和功能多样性的影响仍十分必要。     

Differences in swimming and diving abilities between two sympatric species of water shrews: <Emphasis Type="Italic">Neomys anomalus</Emphasis> and <Emphasis Type="Italic">Neomys</Emphasis><Emphasis Type="Italic">fodiens</Emphasis> (Soricidae)

Swimming and diving abilities of two syntopic species of water shrews, Neomys anomalus and Neomys fodiens, were tested in aquaria using video recordings taken from three views (lateral distant, lateral close and dorsal). The frequency and total duration of diving, as well as the mean duration of diving and floating bouts, were significantly higher in N. fodiens than in N. anomalus. Frequency of paddling during surface swimming was lower in N. fodiens than in N. anomalus. N. fodiens dived mainly for long distances at the bottom of the aquarium and performed a wider range of dive profiles than N. anomalus, which preferred rather short and shallow dives. The two species differed also significantly in their fineness ratios (describing how streamlined their bodies are) when diving. When swimming, N. fodiens had a relatively wider body and performed narrower movements with its tail than N. anomalus. These results show quantitatively and qualitatively for the first time that N. fodiens is more proficient at swimming and diving than N. anomalus. The results also help to explain the inter-specific differences in efficiency of underwater foraging, and support the idea of segregation of ecological niches of these species based on their different foraging modes (diving vs. wading).