Cyprinid Fish Species Research Articles

尾鳍缺失和恢复生长对不同生境的两种鲤科鱼类快速启动游泳能力的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 尾鳍缺失和恢复生长对不同生境的两种鲤科鱼类快速启动游泳能力的影响 DOI: 10.5846/stxb201305171097 作者: 作者单位: 重庆师范大学 进化生理与行为学实验室 动物生物学重庆市重点实验室,重庆师范大学 进化生理与行为学实验室 动物生物学重庆市重点实验室,重庆师范大学 进化生理与行为学实验室 动物生物学重庆市重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(31172096);重庆市自然科学基金重点项目(cstc2013jjB20003);重庆市教委科研项目(KJ130624) The effects of caudal fin loss and regeneration on fast-start performance in juveniles of two cyprinid fish species Author: Affiliation: Laboratory of Evolutionary Physiology and Behaviour,Chongqing Key Laboratory of Animal Biology,Chongqing Normal University,Laboratory of Evolutionary Physiology and Behaviour,Chongqing Key Laboratory of Animal Biology,Chongqing Normal University,Laboratory of Evolutionary Physiology and Behaviour,Chongqing Key Laboratory of Animal Biology,Chongqing Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了考查尾鳍切除及其恢复生长对偏好静水环境的鲫鱼(Carassius auratus)与偏好激流环境的宽鳍鱲(Zacco platypus)两种鲤科鱼类快速启动游泳能力的影响,将鲫鱼幼鱼((6.34 ± 0.02) cm)和宽鳍鱲幼鱼((6.26 ± 0.12) cm)各16尾,其中8尾在(25.0 ± 0.5) ℃的条件下分别进行尾鳍切除、20 d恢复生长、再次切除处理,另外8尾作为对照组;测量计算两种实验鱼的相关形态参数并采用电刺激方式,通过高速摄像机获取实验鱼的影像资料,分析计算后获得快速启动相关参数。结果显示:鲫鱼的细度比(FR)显著小于宽鳍鱲(P < 0.01),尾鳍指数(FI)却显著大于宽鳍鱲(P < 0.01),两种实验鱼的快速启动最大线速度(Vmax)、移动距离(d)、相对旋转半径(RTr)和弯曲指数(BC)均无显著差异;尾鳍切除后,两种实验鱼快速启动的Vmax、d和RTr与正常组相比均呈现显著下降(P < 0.01),其中鲫鱼Vmax下降39%而宽鳍鱲下降24%;经过20 d的恢复生长,两种实验鱼的尾鳍面积均恢复至切除前的60%,而快速启动的Vmax、d、RTr和BC却与正常组(同样经过20 d生长)无显著差异;尾鳍再次切除后与正常组相比,鲫鱼和宽鳍鱲Vmax的下降幅度(17%和9%)与首次切除后的(39%和24%)相比均呈现降低的趋势,其中鲫鱼的下降幅度更大;尾鳍再次切除后与正常组相比,宽鳍鱲的BC显著增大(P = 0.046)。结果表明:(1)鲫鱼尾鳍对快速启动能力的作用大于宽鳍鱲;(2)而偏好急流环境的宽鳍鱲经过恢复生长表现出更加明显的功能补偿现象。 Abstract:Swimming performance is an important capacity for fish species because it is closely related to the ability to gain food, to predator avoidance and to other daily activities. As an important locomotive organ for most fish species, the caudal fin plays a crucial role in propelling and guiding fish during swimming and thus the shape, size and stiffness of the caudal fin are all expected to strongly affect swimming performance. In nature, the caudal fins of fish species are frequently lost to some extent by aggressive behaviour, predation and diseases. To investigate the effects of caudal fin loss and regeneration on fast-start performance of crucian carp (Carassius auratus, inhabiting in still water) and pale chub (Zacco platypus, inhabiting in rip current), 16 juveniles of both crucian carp (body length, (6.27 ± 0.04) cm) and pale chub (body length, (6.14 ± 0.12) cm) were allocated to two groups, respectively. One group (8 fish for each treatment) for the treatment of caudal-fin-amputation-regeneration (20 days) and re-amputation, the other group (8 fish for each treatment) for control. The movement of each fish was recorded by a high-speed camera after an electric stimulation for the analysis of fast-start parameter. Furthermore, the morphological parameters such as body length (L), body height (H), fitness ratio (FR), caudal fin aspect ratio (AR), relative caudal fin area ratio and caudal fin index (FI) in the two cyprinid fish species were measured. The experimental water temperature was maintained at (25.0 ± 0.5)℃. The results showed that the crucian carp showed a significant lower FR and higher FI than pale chub (P < 0.01), but the maximum linear velocity (Vmax), escape distance (d), relative turning radius (TRr) and bending coefficient (BC) showed no significant difference between the two cyprinid fish species. The Vmax, d and TRr during fast-start process of both fish species decreased significantly after caudal fin loss (P < 0.01), with the Vmax of crucian carp decreased by 39% while that of pale chub decreased by 24% after caudal fin loss. After 20 days' recovery, the areas of caudal fin of both fish species recovered about 60% those of the caudal-fin-intact fish. However, the Vmax, d, RTr and BC of both caudal-fin-regenerated crucian carp and pale chub showed no significant difference compared with those of the control groups, respectively. Compared to the caudal-fin-intact fish, the decrease of Vmax of crucian carp and pale chub after the second amputation (17% and 9%) was smaller than the first amputation (39% and 24%). The decrease ratio between the first and the second caudal fin amputation in crucian carp was larger than that of pale chub. However, the bending coefficient (BC) of pale chub increased significantly after the second caudal fin amputation compared with those of fin-intact group (P = 0.046). The results indicated that (1) the caudal fin of crucian carp played a more important role than that of pale chub during fast-start movement; and (2) the pale chub which prefer to rip current habitat showed more significant functional compensation after 20 days' recovery. 参考文献 相似文献 引证文献

Relationships between fish length and otolith size for five cyprinid speciesfrom Lake Ladik, Samsun, Turkey

The relationships between size (length and width) of the lagenar (asteriscus) and the utricular (lapillus) otoliths and body length for five cyprinid fish species, freshwater bream Abramis brama, white bream Blicca bjoerkna, Prussian carp Carassius gibelio, brond-snout Chondrostoma regium, and rudd Scardinius erythrophthalmus, collected from Lake Ladik from November 2009 through October 2010, are presented. The right and left side measurements of otoliths were pooled in all cases except asteriscus length in Prussian carp. Nonlinear and linear functions provided the best fit for 80% and 20% of all species, respectively. All relationships were highly significant (P < 0.001, R2 > 0.71) and the mean percent prediction errors were less than 10%. The results showed that reliable original size estimates of all species studied are obtainable from their otolith biometrics. The regressions from this study can be useful for investigators examining food habits of piscivorous fauna and sizes of these fishes in archaeological samples.

Newly identified gene muscle segment homeobox C may play a role in intermuscular bone development of Hemibarbus labeo.

Intermuscular bones, ossified from tendons within the myosepta, occur only in teleost fish. Current understanding of the homology and origins of intermuscular bones in fishes is based mainly on morphological data. To date, there is no published data regarding molecular mechanisms of intermuscular bone formation. In this study, we cloned the gene muscle segment homeobox C (MsxC). MsxC potentially plays a role in intermuscular bone development of Hemibarbus labeo, an important species of cyprinid fish in the Chinese aquaculture industry. Sequence analysis of MsxC revealed motifs characteristic of the homeobox domain family. Whole-mount in situ hybridization showed that MsxC was primarily expressed in the myosepta and brain. MsxC was expressed in the myosepta from 26 to 41 days after hatching (DAH); this coincided with the onset of intermuscular bone ossification, which occurred between 35 and 62 DAH. Evidence for localization of MsxC expression by in situ hybridization correlated with its detection by quantitative real-time PCR. In vertebrates, MsxC plays a role in the regulation of mesenchymal cell differentiation during bone formation. We therefore conclude that MsxC may have a role in epithelium-mesenchyme interactions during intermuscular bone formation in H. labeo.

Length-weight relationships of three cyprinid fishes from headwater of the Nujiang River, China

Length-weight relationships (LWR) for three cyprinid fish species collected from the headwaters of the Nujiang River in Tibet, China, were determined. The values of parameter b in the LWR equations were estimated as 2.54 for Schizopygopsis thermalis, 3.3 for Ptychobarbus kaznakovi, and 2.74 for Schizothorax nukiangensis, respectively. These are the first LWR records for the three species.

Barbel habitat alterations due to hydropeaking

The effects of hydropeaking in the habitat of the Iberian barbel (Luciobarbus bocagei) a native cyprinid fish species of the Iberian Peninsula, were investigated. Two study sites were selected in the Ocreza River, Mid-Eastern Portugal. A regulated site located immediately downstream from a hydropower dam, and an unregulated site located on a lotic undisturbed segment upstream the reservoir. The habitat preferences were determined based on field data collection and displayed by means of fuzzy sets and rules for juvenile and adult life-stages of barbel. The River2D and CASiMiR Fish 2D model were applied to both river sites in the Ocreza River to simulate how physical habitat conditions vary with powerhouse operation. Results indicate that hydropeaking impact is strongly dependent on river morphology. The more heterogeneous the river is the better it can support areas of suitable habitat, including shelters. Whatsoever, stranding is an associated risk. Furthermore, shifts in the array of habitats were due to occur between the base and peak flow. The study outcomes provide comprehensive information on the barbel response to hydropeaking. Understanding how hydropeaking influences both habitat availability and population dynamics is a crucial point to help guiding hydropower managers towards more sustainable practices.

Population structure of Opisthorchis felineus (Trematoda) and its second intermediate hosts — cyprinid fishes in the Ob-Irtysh focus of opisthorchiasis, based on allozyme data

Abstract Genetic variability of West Siberian populations of Opisthorchis felineus and two species of cyprinid fish, its second intermediate hosts, was studied by isozyme analysis. Low levels of allozyme variation and genetic differentiation in O. felineus from the Ob-Irtysh focus of opisthorchiasis were detected. The proportion of polymorphic loci was 21.1 %, the average observed heterozygosity (Hobs) was 0.008, and expected heterozygosity (Hexp) was 0.052. For most loci in O. felineus deficit of heterozygotes (FIS = 0.7424) was observed. A comparison of population genetic structure of fish and parasites showed they were not congruent. Estimates of genetic differentiation of the parasite were smaller than for the fish — its intermediate host. Migration and population structure of the second intermediate hosts do not play an important role in formation of the population-genetic structure of O. felineus in the Ob-Irtysh focus of opisthorchiasis.

New Oligocene cyprinid in the central Tibetan Plateau documents the pre-uplift tropical lowlands

A new Oligocene-aged genus and species of cyprinid fish, Tchunglinius tchangii, from the Nima Basin in the center of the Tibetan Plateau is described. The new genus is assigned to the subfamily Cyprininae because of its protractile mouth, spoon-shaped pharyngeal teeth, dorsal fin originating anterior to the insertion of the pelvic fin, dorsal fin with four unbranched rays and anal fin with three unbranched rays. This genus differs from other cyprinine genera on the characteristic combination of large head and low body; also, the head length is larger than the body depth. Other differences include the following: the last unbranched ray of both dorsal and anal fin is smooth and articulated; it has an eight-branched ray in the dorsal fin and a five-branched ray in the anal fin; and it has five supraneurals, five hypurals and 33 vertebrae. Tchunglinius tchangii is closely related to recent small-bodied South-Asian cyprinine genera such as Puntius in small body size; therefore, the fossil reflects the Paleogene tropical–subtropical lowland fish fauna present there before the uplift of the Tibetan Plateau.

Molecular and functional characterization of the scavenger receptor CD36 in zebrafish and common carp

CD36 is a scavenger receptor which has been studied closely in mammals where it is expressed by many different cell types and plays a role in highly diverse processes, both homeostatic and pathologic. It is among other things important in the innate immune system, in angiogenesis, and in clearance of apoptotic cells, and it is also involved in lipid metabolism and atherosclerosis. Recently, in the cephalochordate amphioxus a primitive CD36 family member was described, which was present before the divergence of CD36 from other scavenger receptor B family members, SCARB1 and SCARB2. Not much is known on the Cd36 molecule in teleost fish. We therefore studied Cd36 in both zebrafish and common carp, two closely related cyprinid fish species. Whereas a single cd36 gene is present in zebrafish, carp has two cd36 genes, and all show conserved synteny compared to mammalian CD36. The gene expression of carp cd36 is high in brain, ovary and testis but absent in immune organs. Although in mammals CD36 expression in erythrocytes, monocytes and macrophages is high, gene expression studies in leukocyte subtypes of adult carp and zebrafish larvae, including thrombocytes and macrophages provided no indication for any substantial expression of cd36 in immune cell types. Surprisingly, analysis of the cd36 promoter region does show the presence of several binding sites for transcription factors known to regulate immune responses. Overexpression of carp cd36 locates the receptor on the cell surface of mammalian cell lines consistent with the predicted topology of cyprinid Cd36 with a large extracellular domain, two transmembrane domains, and short cytoplasmic tails at both ends. Gene expression of cd36 is down-regulated during infection of zebrafish with Mycobacterium marinum, whereas knockdown of cd36 in zebrafish larvae led to higher bacterial burden upon such infection. We discuss the putative role for Cd36 in immune responses of fish in the context of other members of the scavenger receptor class B family.

Determination of 28 trace elements in three farmed cyprinid fish species from Northeast China

The concentrations of 28 trace elements (Li, V, Cr, Mn, Fe, Ni, Cu, Mo, Zn, Se, Sr, Co, Al, Ti, As, Cd, Sb, Ba, Hg, Pb, U, Ag, Be, TI, Ga, Te, Sn, Tm) in three farmed cyprinid fish species (common carp – Cyprinus carpio , crucian carp – Carassius carassius , grass carp – Ctenopharyngodon idella ) from Northeast China were determined. The mean concentrations obtained for elements analyzed in mg/kg were as follows: Li(0.01), V(0.019), Cr (0.121), Mn (0.136), Fe (6.71), Ni (0.119), Cu (0.293), Mo (0.015), Zn(7.90), Se (0.243), Sr (1.171), Al (6.30), Ti (0.237), As (0.096), Cd (0.11), Sb (0.11), Ba (0.193), Hg (0.013), Pb (0.172) and U (0.004), with low detective rate for Co, Be, Ga, Ag, Sn, Te, Tm and Tl. Significant differences in concentrations of analyzed elements were found among the three provinces while crucian carp accumulated the highest total trace elements. Samples with 0.56% (As), 1.13% (Cd) and 9.04% (Pb) were exceeding the maximum residue limits established by Chinese legislation and further health risk assessment showed Pb, Cd and As were the major risk contributors. The hazard index (HI) at average exposure and high exposure level were all less than one. Overall, results indicate that the intake of farmed fish are safe for consumers in Northeast China and we suggest that As, Cd and Pb should be the most important monitored targets which should warrant concern. • Comprehensive survey of 28 trace elements in farmed fish from Northeast China. • Fish samples with 0.56% (As), 1.13% (Cd) and 9.04% (Pb) were above MRL. • HI and TR suggest farmed fish are generally safe to consumers. • Arsenic (As), Cd and Pb should be the most important monitored targets.

A new genus and species of cyprinid fish (Actinopterygii, Cyprinidae) from the Arabian Peninsula, and its phylogenetic and zoogeographic affinities

Arabibarbus hadhrami, a new species of cyprinid fish from the Hadhramaut Province of Yemen, is described. It has modally 30 scales (29–32) in the lateral line, the wedge-shaped head is longer (27.8–32.5 % SL) and higher (15.5–18.4 % SL) than in its congeners. The body is slender and laterally flattened. The dorsal fin is high (26.5–32.4 % SL) and well ossified. The pectoral fins (19.9–23.9 % SL) and pelvic fins (16.8–19.8 % SL) are longer than in its congeners. Two closely related species, Arabibarbus arabicus and Arabibarbus grypus are re-described and compared to the new species. Based on morphological and molecular characters the new genus Arabibarbus is erected for these three species. It is characterised by medium to large body size, an ossified, smooth principal dorsal fin ray, eight branched dorsal and five branched anal fin rays, large shield-shaped scales with numerous parallel radii, a lateral line with 29 to 44 scales, pharyngeal teeth that are hooked at their tips, their count being 2.3.5–5.3.2 and the possession of two pairs of barbels. Arabibarbus hadhrami is the type species of the new genus. The phylogenetic position of the new genus is analysed, based on the mitochondrial cytochrome b gene. It is the sister taxon to the genus Carasobarbus Karaman, 1971 and closely related to Mesopotamichthys Karaman, 1971, Pterocapoeta Gunther, 1902 and ‘Barbus’ reinii Gunther, 1874. Arabibarbus probably colonised the Arabian Peninsula about 4 Ma ago, coming from the Tigris-Euphrates drainage in the East via Wādī ar Rimah/Wādī al Bāţin.

Analysis of the population genetics of Opisthorchis viverrini sensu lato in the Nam Ngum River wetland, Lao PDR, by multilocus enzyme electrophoresis.

A previous population genetics study of Opisthorchis viverrini from a locality in an endemic area in Thailand found little genetic variation over time and second intermediate fish host species. Since a similar comparative analysis is not available for Lao PDR, we conducted a study of O. viverrini from different endemic foci in Vientiane Province, Lao PDR, based on spatial, temporal and fish host species. A total of 620 adult O. viverrini originating from the Nam Ngum River wetland were analysed at five previously defined polymorphic enzyme loci. Of these worms, 252 were from six different localities (spatial samples), 162 worms from different years (temporal samples) and 206 worms from four different cyprinid fish species. Significant heterozygote deficiency was found in most O. viverrini populations with levels of genetic differentiation ranging between F ST 0.0000 and 0.0197 suggesting that gene flow occurred at a variable rate. The role of temporal factors and fish host species had little influence on the level of genetic differentiation. As for O. viverrini from Thailand, these findings indicate that self-fertilization and/or a clonal distribution of O. viverrini occurs in Lao PDR. Unlike the results for O. viverrini from Thailand, spatial population substructuring may be the underlying population processes for O. viverrini in Lao PDR. These findings indicate that geographical variation may contribute to the transmission dynamics of the parasite with implications for parasite control. However, other host factors, such as snail intermediate hosts and mammal reservoir hosts, as well as human beings, may also play significant roles.

Suppression of invasive topmouth gudgeon Pseudorasbora parva by native pike Esox lucius in ponds

Abstract Asian topmouth gudgeon Pseudorasbora parva has been recognized as a highly invasive cyprinid fish species in Europe that may present risk to native fish communities. The present study aimed to investigate whether a native piscivorous fish, pike Esox lucius, is able to reduce the establishment success and invasiveness of topmouth gudgeon in shallow ponds. A large‐scale, replicated whole‐pond experiment was performed in which ponds were spontaneously colonized by topmouth gudgeon and exposed to experimental native fish communities with and without pike. The results of the present study provide evidence for strong negative effects of pike stocking on the abundance and biomass of topmouth gudgeon, while no effects on native fish species were found. The present study suggests that the presence of native pike can considerably enhance the biotic resistance of fish communities against invasion by topmouth gudgeon. It is argued that the resistance of fish communities against invasion by exotic species may in some cases be enhanced by management strategies that reinforce the presence and abundance of pike. Copyright © 2014 John Wiley &amp; Sons, Ltd.

Age-related differences in prey-handling efficiency and feeding habitat utilization of Squalius carolitertii (Cyprinidae) according to prey trait analysis

Multivariate prey trait analysis is a functional approach to understand predator-prey relationships. Here, seven macroinvertebrate ecological traits have been used for the analysis of trophic ecology of co-occurring age classes of Northern Iberian chub Squalius carolitertii, a cyprinid fish species. The present study identified several key factors in the handling efficiency and habitat utilization for feeding of S. carolitertii that may have a wider application, particularly for other cyprinid species. The results revealed a remarkable similarity in the feeding behaviour among age classes, suggesting a foraging behaviour convergence among them in both prey-handling efficiency and feeding habitat utilization. Nevertheless, some age classes showed clear preferences for particular categories of ecological trait; for example, age 1 showed a clear ability to feed on flattened prey items, whereas ages 2 and 3 were able to feed on preys with different body shape due to their general distribution in the fuzzy principal component analysis (FPCA). Finally, this study shows how multivariate approaches can complement traditional diet analyses, and the method has wide applicability across life-stages of cyprinid species.

Molecular cloning of Pcc-dmrt1s and their specific expression patterns in Pengze crucian carp (Carassius auratus var. Pengze) affected by 17α-methyltestosterone

Dmrt1, an important transcription factor associated with testicular differentiation, is conserved among teleost, which could also be detected in ovaries. In the present study, three isoforms of Pcc-dmrt1s (Pcc-dmrt1a, Pcc-dmrt1b and Pcc-dmrt1c) resulting from alternative splicing of the dmrt1 gene were cloned and characterized in the triploid gynogenetic fish, the Pengze crucian carp. Their mRNA expression profiling was investigated in juvenile developmental stages, tissues of the adult fish, and the juveniles under 84.2ng/L 17α-methyltestosterone (MT) treatments. Results showed that their putative proteins shared high identities to Dmrt1 in cyprinid fish species. Gene expression profiling in the developmental stages showed that all the three target genes had a highest/lowest expression at 56/40days post-hatching (dph), respectively. The period of 40 dph appeared to be a key time during the process of the ovary development of Pengze crucian carp. The tissue distribution results indicated that Pcc-dmrt1s were predominantly expressed in hepatopancreas, brain, spleen and ovary of the female fish. MT significantly increased the mRNA expression of Pcc-dmrt1a (all 4-week exposures) and Pcc-dmrt1b (except for week 2), while repressed Pcc-dmrt1c transcripts at all exposure period except for week 2. MT extremely significant repressed cyp19a1a transcripts for 1week. The present study indicated that MT could influence the ovary development of Pengze crucian carp by disturbing gene expressions of Pcc-dmrt1s and cyp19a1a. Furthermore, the present study will be of great significance to broaden the understanding of masculinizing pathway during ovary development in gynogenetic teleost.

Ex situ reproduction of Portuguese endangered cyprinids in the context of their conservation

The captive breeding of highly endangered species is considered to be an indispensable instrument when the natural habitats of those species are extremely degraded and/or when the effective population sizes are so reduced that there is an eminent risk of extinction (Bentsen and Olesen 2002; Maitland and Morgan 2002; Faria et al. 2010). Several authors agree that captive breeding programs do not completely solve conservation problems and should only be adopted as a safeguard against species extinction until the natural habitats are restored and the animals can be reintroduced into their original habitats under appropriate conditions (Johnson and Jensen 1991; Philippart 1992; Caughley and Gunn 1996; Naslund 1998; Snyder et al. 1999; Berejikian 2000; Bobori et al 2001; Maitland and Morgan 2002; Schonhuth et al. 2003), a strategy known as supportive breeding (Wang and Ryman 2001). This strategy has been applied in several countries when it is urgent to preserve fish populations in considerable risk of extinction (Cambray 1997; Arkush and Siri 2001; Schonhuth et al. 2003; CIP El Palmar 2006; Cardoso and Carrapato 2008; Kitanishi et al. 2013). Indeed, a vast array of factors is threatening freshwater fishes at a global scale (Duncan and Lockwood 2001). The Mediterranean populations are among the most threatened (Hermoso and Clavero 2011) due to the introduction of alien species, impoundment of rivers, habitat degradation and fragmentation, summer droughts and water quality deterioration (Collares-Pereira and Cowx 2004). In the Iberian Peninsula there is a consistent spatial relationship between the incidence of threats and the level of imperilment of species, whereby the presence of invasive species and the water extraction are the main drivers of native fish declines (Clavero et al. 2010). With the tendency for global warming, the typical summer droughts in Iberia are expected to become more intense and extended in time. This could pose an additional extinction risk factor for the Portuguese native cyprinid fish species, around 67 % of which are already considered to be ‘‘Threatened’’, ‘‘Vulnerable’’ or ‘‘Critically endangered’’ according to the Portuguese Red Book [Cabral et al. 2005; Electronic Supplementary Material (ESM) Table S1]. These species are small cyprinids with no economical value, which show restricted geographic ranges and low levels of genetic diversity (Sousa-Santos et al. 2013). A pioneer project of supportive breeding of critically endangered endemic fish species started in 2007 with nine populations belonging to six endangered and critically endangered cyprinid species endemic to the Iberian Peninsula: Achondrostoma occidentale, Iberochondrostoma almacai, Iberochondrostoma lusitanicum, Squalius pyrenaicus, Squalius aradensis and Squalius torgalensis (Fig. 1; Table 1). In this paper we describe the implementation and major results of this project and discuss the advantages of the adopted breeding scheme. Also, potential disadvantages of supportive breeding programs targeting endangered fish species are discussed. Ex situ conditions and the adoption of a ‘‘naturalistic approach’’ of reproduction. Following the research Electronic supplementary material The online version of this article (doi:10.1007/s10228-013-0383-6) contains supplementary material, which is available to authorized users.

A New Species of Cyprinid Fish of Genus Opsariichthys from Ky Cung-Bang Giang River Basin, Northern Vietnam with Notes on the Taxonomic Status of the Genus from Northern Vietnam and Southern China

Opsariichthys duchuunguyeni, a new species of cyprinid fish from Ky Cung-Bang Giang river basin, northern Vietnam, is described. It is characterized by the following unique combination of features: short maxillary extending; 12-15 rounded tubercles on lower jaw; 11-12 crossbars on body; pectoral fin reaching the pelvic fin origin in adult male; lateral- line scales comprising 41; scales above lateral-line 8; scales below lateral-line 3. Moreover, the genetic differentiation and a diagnostic key of the new species and other congeners are given in this paper for discussion about taxonomic status of the genus Opsariichthys from Vietnam and nearby geographical regions, southern China and Taiwan.

Male Ornamentation in the European Minnow (Phoxinus phoxinus) Signals Swimming Performance

AbstractThe association between male secondary sexual ornamentation and male quality has been under intensive study for decades. It has been shown that male ornaments in fish indicate a variety of physical and genetic qualities. However, only few studies have investigated whether male ornaments signal locomotor performance, a trait that is expected to be vital for individual fitness in the nature. In this study, we sampled two populations of European minnow (Phoxinus phoxinus), a cyprinid fish species with spectacular and colourful male breeding ornamentation, and examined the association between male ornaments (tubercle number, lateral darkness and abdominal redness), swimming performance, and three fitness‐related traits, body length (LT), condition factor (K) and gonadosomatic index (GI). We found that male tubercle number and abdominal redness were positively correlated with their swimming performance. In addition, these two ornaments were correlated with male fitness‐related traits, which in turn were also directly associated with the swimming performance. In general, these results suggest that in the European minnow male ornamentation may act as an honest signal of several fitness‐related traits and locomotor performance in the nature.

Seasonal changes in infrapopulations of Diplozoon kashmirensis Kaw, 1950 (Monogenea: Diplozoidae) along a eutrophic gradient

Seasonal population dynamics of the monogenean, Diplozoon kashmirensis Kaw, on the gills of two cyprinid fish species, Schizothorax niger Heckel and Carassius carassius (Linnaeus), was investigated in three limnologically distinct trophic habitats located along the flood plain of River Jhelum in Kashmir from June 2006 to May 2008. The parasite infrapopulations exhibited a marked seasonal regime in infestation pattern as the infection indices increased to a much higher plateau during summer season at all the lakes, while the lows were recorded in winter. The heterogeneity in infection pattern indicates that water temperature is an important determinant of the seasonality of infrapopulations at all the localities. Furthermore, the results of our work clearly indicate that the parasite infrapopulations increased proportionally with eutrophication level and, as such, the highly eutrophic habitat, Anchar Lake, was significantly more favourable for parasite infrapopulations than the less eutrophic ones. However, the lakes presented no significant interlake differences in water temperature. Therefore, we could argue that interlake differences in the infestation pattern of parasite can be safely attributed to respective water quality in the lakes rather than water temperature. We propose that infrapopulations of the diplozoid studied herein do respond to differences in water quality of lakes and, thus, could qualify as simple and reliable indicator species in short-term comparative assays by lake managers.

Acute Toxicity, Respiratory Reaction, and Sensitivity of Three Cyprinid Fish Species Caused by Exposure to Four Heavy Metals

Using 3 cyprinid fish species zebra fish, rare minnow, and juvenile grass carp, we conducted assays of lethal reaction and ventilatory response to analyze sensitivity of the fish to 4 heavy metals. Our results showed that the 96 h LC50 of Hg2+ to zebra fish, juvenile grass carp, and rare minnow were 0.14 mg L−1, 0.23 mg L−1, and 0.10 mg L−1, respectively; of Cu2+0.17 mg L−1, 0.09 mg L−1, and 0.12 mg L−1 respectively; of Cd2+6.5 mg L−1, 18.47 mg L−1, 5.36 mg L−1, respectively; and of Zn2+44.48 mg L−1, 31.37 mg L−1, and 12.74 mg L−1, respectively. Under a 1-h exposure, the ventilatory response to the different heavy metals varied. Ventilatory frequency (Vf) and amplitude (Va) increased in zebra fish, juvenile grass carp, and rare minnows exposed to Hg2+ and Cu2+ (P<0.05), and the Vf and Va of the 3 species rose initially and then declined when exposed to Cd2+. Zn2+ had markedly different toxic effects than the other heavy metals, whose Vf and Va gradually decreased with increasing exposure concentration (P<0.05). The rare minnow was the most highly susceptible of the 3 fish species to the heavy metals, with threshold effect concentrations (TEC) of 0.019 mg L−1, 0.046 mg L−1, 2.142 mg L−1, and 0.633 mg L−1 for Hg2+, Cu2+, Cd2+, and Zn2+, respectively. Therefore, it is feasible to use ventilatory parameters as a biomarker for evaluating the pollution toxicity of metals and to recognize early warning signs by using rare minnows as a sensor.

Garra dampaensis, a new ray-finned fish species (Cypriniformes: Cyprinidae) from Mizoram, northeastern India

Garra dampaensis, a new cyprinid fish species, is described from the Seling River, a tributary of the Khawthlang Tuipui (Karnaphuli River), in Mizoram, India. The species can be distinguished from all other Garra species, except G. abhoyai, G. lissorhynchus, G. nambulica, G. paralissorhynchus and G. rupecula by the presence of a distinct W-shaped black band on the caudal fin. It can be distinguished from the above mentioned five species in having scales on the breast and belly, shorter vent to anal distance, and by having fewer lateral line scales (27-29 vs. more than 29 in all other species). A key to the species of Garra in the Lissorhynchus complex is provided.