Anthropomorphism and 'mental welfare' of fishes

Anthropomorphism, the use of human characteristics as a foundation for interpreting behavior and mental capacities of animals, is a bias undermining our understanding of other species, especially species as evolutionarily distant from humans as fishes. Anthropomorphism is not justified by allusions to evolutionary continuity among vertebrates, because no living vertebrate was ever a descendant of humans, so none could have inherited human traits. Nonetheless, it has recently been claimed that fishes are capable of conscious experiences of pain and emotional feelings and that mental welfare is an important issue for fishes. This paper shows that the evidence supporting claims for experiences of pain or conscious emotions by fishes is conceptually and methodologically flawed. In addition, the paper shows that the natural history and behavior of diverse fish species is inconsistent with a presumption of human-like awareness. This behavioral evidence is in accord with neurobiological observations showing that fishes are very different from us and are unlikely to have a capacity for awareness of pain or emotional feelings that meaningfully resemble our own. The factors that are detrimental to fish welfare have been well delineated by valid, objective indicators of physiological and behavioral well-being. This knowledge should guide welfare decisions. An empirical and non-anthropomorphic examination of diverse fishes and their adaptations should be the foundation for welfare decisions that would be truly beneficial to fishes and humans alike.     

Handed foraging behavior in scale-eating cichlid fish: its potential role in shaping morphological asymmetry

Scale-eating cichlid fish, Perissodus microlepis, from Lake Tanganyika display handed (lateralized) foraging behavior, where an asymmetric 'left' mouth morph preferentially feeds on the scales of the right side of its victim fish and a 'right' morph bites the scales of the left side. This species has therefore become a textbook example of the astonishing degree of ecological specialization and negative frequency-dependent selection. We investigated the strength of handedness of foraging behavior as well as its interaction with morphological mouth laterality in P. microlepis. In wild-caught adult fish we found that mouth laterality is, as expected, a strong predictor of their preferred attack orientation. Also laboratory-reared juvenile fish exhibited a strong laterality in behavioral preference to feed on scales, even at an early age, although the initial level of mouth asymmetry appeared to be small. This suggests that pronounced mouth asymmetry is not a prerequisite for handed foraging behavior in juvenile scale-eating cichlid fish and might suggest that behavioral preference to attack a particular side of the prey plays a role in facilitating morphological asymmetry of this species.     

Laterality of the initial stage of escape response in roach (<Emphasis Type="Italic">Rutilus rutilus</Emphasis>) upon impact of alternating electric current

The initial stage of the escape response (C-bend of the body) upon sudden impact of electric current on free-swimming fish was studied in young roach (Rutilus rutilus). More than half of the fish showed distinct behavioral laterality, i.e., a stabile tendency to bend either to the left or to the right, and retained it until the next test conducted 10 days later. The majority of fish bent to the left, but the difference between the proportions of individuals that showed opposite lateralities lacked statistical significance. This response and the type of laterality are stable and simple to record, which makes the C-bend a convenient experimental model for studying behavioral asymmetry in fishes.     

四种鲤科鱼类对捕食胁迫行为响应的种间比较

为了比较早期捕食胁迫经历和当前环境中存在的捕食者对鱼类行为的影响, 并考查这些影响是否存在种间差异, 研究分别考查了测定环境(有、无捕食者存在)对有、无捕食胁迫经历的鳊(Parabramis pekinensis)、草鱼(Ctenopharyngodon idellus)、鲫(Carassius auratus)和中华倒刺鲃(Spinibarbus sinensis)等4种鲤科鱼类探索性、活跃性和勇敢性的影响。结果发现: 早期捕食胁迫经历与当前环境条件对鱼类行为产生截然不同的影响, 且存在较大的种间差异。无捕食胁迫经历的鳊、草鱼和中华倒刺鲃均会对陌生的捕食者乌鳢(Channa argus)做出行为响应, 提示这3种鱼可能对陌生捕食者具有一定的识别能力, 但这种识别与猎物鱼通过捕食胁迫经历获得的识别仍具有一定差距; 具有捕食胁迫经历的鳊和中华倒刺鲃在空白环境中未表现出反捕食行为, 可能是节约能量的一种策略。总体而言, 草鱼对捕食胁迫经历和测定环境处理反应更为敏感, 而中华倒刺鲃的反应则相对保守。但当周围环境中存在捕食者时, 4种鲤科鱼类均会通过维持较高运动状态的方式来应对捕食者。维持这种应激状态可能对猎物鱼保持与捕食者的距离, 并随时保持警惕较为关键。     

Laterality of behavioral responses in bony fishes: Inheritance,adaptive importance,and morphofunctional correlates

Current data on the relation of locomotory responses laterality to taxonomy and mode of life in fish, as well as to asymmetry of CNS, sensory, and somatic organs, are examined. Although the correlations of behavioral laterality with some of the abovementioned features are already found, the causes inducing lateralities of many fish responses remain unclear. It is concluded that, to understand the causes of laterality, it is necessary to study simultaneously its relation to different morphofunctional features in the same specimens.     

Importance of live coral habitat for reef fishes

Live corals are the key habitat forming organisms on coral reefs, contributing to both biological and physical structure. Understanding the importance of corals for reef fishes is, however, restricted to a few key families of fishes, whereas it is likely that a vast number of fish species will be adversely affected by the loss of live corals. This study used data from published literature together with independent field based surveys to quantify the range of reef fish species that use live coral habitats. A total of 320 species from 39 families use live coral habitats, accounting for approximately 8 % of all reef fishes. Many of the fishes reported to use live corals are from the families Pomacentridae (68 spp.) and Gobiidae (44 spp.) and most (66 %) are either planktivores or omnivores. 126 species of fish associate with corals as juveniles, although many of these fishes have no apparent affiliation with coral as adults, suggesting an ontogenetic shift in coral reliance. Collectively, reef fishes have been reported to use at least 93 species of coral, mainly from the genus Acropora and Porities and associate predominantly with branching growth forms. Some fish associate with a single coral species, whilst others can be found on more than 20 different species of coral indicating there is considerable variation in habitat specialisation among coral associated fish species. The large number of fishes that rely on coral highlights that habitat degradation and coral loss will have significant consequences for biodiversity and productivity of reef fish assemblages.     

Pattern and process in the geographical ranges of freshwater fishes

North American freshwater fishes were studied to determine whether they displayed the same relationships between log (geographical range size) and log (body size) and the same pattern of range shape as found among North American birds and mammals. The forces that produce these patterns were also investigated. The log (geographical range size) : log (body size) relationship was analysed for 121 North American freshwater fish species. Thirty‐two imperilled species were compared with 89 non‐imperilled species to determine if the overall relationship could result from differential extinction. Range geometries were analysed, within and among habitat guilds, to determine if general patterns could be detected. The log (geographical range size) : log (body size) pattern among freshwater fish species was triangular and qualitatively similar to that found for North American birds and mammals. The results suggest that below a minimum geographical range, the likelihood of extinction increases dramatically for freshwater fishes and that this minimum range size increases with body size. The pattern of fish species’ range shapes differs from that found for other North American vertebrate taxa because, on average, fish possess much smaller ranges than terrestrial species and most fish species’ geographical ranges extend further on a north–south axis than on an east–west axis. The log (geographical range size) : log (body size) pattern reveals that fish species’ geographical ranges are more constrained than those of terrestrial species. The triangular relationship may be caused by differential extinction of species with large bodies and small geographical ranges as well as higher speciation rates of small‐bodied fish. The restricted geographical ranges of freshwater fishes gives them much in common with terrestrial species on oceanic islands. Range shape patterns within habitat guilds reflect guild‐specific historical and current ecological forces. The overall pattern of range shapes emerges from the combination of ecologically different subunits.     

Non-native fish species in Slovak waters: origins and present status

Freshwater fishes recorded in the territory of Slovakia include 95 fish species. As many as one third of these are allochthonous fish species belonging to 14 families, among which several have not occurred in Slovakia recently. Historically, there were three main periods of introduction: the first is the beginning of the 20^th century, the second includes two decades between 1955 and 1975 and the third period is from the year 1990 up to the present time. The origins of the exotic species seen in Slovakia are the four continents — Africa (3), North America (7), Central America (3), and Asia (13) and ten of them are from different regions in Europe. The purpose of intentional introductions of non-native species was to occupy vacant ecological niches in the ecosystems reshaped by human activities, fish stocking, angling or fish farming. Some of these species spread from their original ranges or they penetrated spontaneously from the adjacent countries via the river network system. At the present time, 76 fish species in total form populations in Slovakia. There are 54 autochthonous and 22 allochthonous species, 14 of them are exotic fishes. The invasive characters in 13 fish species were considered, the recent native/total fish ratio is 0.71.     

Laterality Influences Schooling Position in Rainbowfish,Melanotaenia spp

Cerebral lateralization is a widespread trait among animals, is often manifested as side biases in behaviour (laterality) and has been suggested to provide fitness benefits. Here we examined the influence of laterality on the organisation of fish schools using rainbowfish (Melanotaenia spp) as model species. The pattern and strength of laterality for each individual was determined by examining eye preferences whilst examining their reflection in a mirror. Schools of four fish of known laterality were then created and the preferred position for each fish within the school was repeatedly observed in a flume. Fish which showed right eye preferences in the mirror test preferentially adopted a position on the left side of the school. Conversely, fish that showed left eye preferences in the mirror test or where non-lateralised preferentially adopted a position slightly to the right side of the school. However, this general pattern varied depending on the species and sex of the school. Our results strongly implicate individual laterality in the geometry of school formation.     

Comparison of the oropharyngeal cavity in the Starksiini (Teleostei: Blenniiformes: Labrisomidae): Taste buds and teeth,including a comparison with closely‐related genera

The present study describes the distribution of taste buds and teeth in the oropharyngeal cavity of 13 species of adult (18–60 mm SL) Starksiini fishes inhabiting subtidal waters of the Neotropical region. Four types of taste buds described previously in other fish groups were observed within the oropharyngeal cavity, of which type I, situated on prominent protruding papillae, is the most common. The number of taste buds in this cavity varies considerably, ranging from ca. 202 in Starksia lepicoelia to ca. 770 in S. sluiteri. In all the studied species, taste buds are more numerous on the posterior (160–396) than on the anterior (42–294) part of the oropharyngeal cavity. The presence of different numbers of taste buds in different Starksiini species of the same standard length suggests that numbers of taste buds are not directly correlated with size and may be species‐specific. Teeth are found on the premaxilla, dentary, vomer, palatine (in some species) and the upper and lower pharyngeal jaws (third pharyngobranchials and fifth ceratobranchials, respectively); the form and number of teeth and taste buds on each of these sites differs among the various species of Starksiini and between them and closely related species of the labrisomid tribes Labrisomini, Mnierpini, and Paraclinini. The results thus suggest potential systematic value in certain features of the oropharyngeal cavity for blenniiform fishes. It is also shown that benthic‐feeding omnivorous fishes have higher densities of taste buds than piscivorous fishes. A possible correlation among numbers of taste buds, their positions in the oropharyngeal cavity, and other parameters is discussed. J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.     

Freshwater fish biodiversity in the River Ganga (India): changing pattern, threats and conservation perspectives

The river Ganges is the largest river in India and the fifth longest in the world. Although, many studies on fish ecology and systematic have been conducted largely to improve fisheries but fish diversity and their distribution pattern from conservation point of view have never been adequately addressed in the Ganges. In this connection, current distribution and abundance of freshwater fishes of river Ganges was studied and assessed from April 2007 to March 2009. We documented and described 143 freshwater fish species in the all stretches of the river which is higher than what was reported earlier. Some species were observed with shift in their distribution ranges. First time, a total of 10 exotic fishes, including Pterygoplichthys anisitsi, which has never been reported from India found in the Ganges. Alterations of the hydrological pattern due to various types of hydro projects was seems to be the largest threat to fishes of Ganges. Indiscriminate and illegal fishing, pollution, water abstraction, siltation and invasion of exotic species are also threatening the fish diversity in the Ganges and as many as 29 species are listed under threatened category. The study advocates a need to identify critical fish habitats in the Ganga basin to declare them as conservation reserves to mitigate the loss of fish diversity from this mighty large river.     

长江湖口段春夏季仔稚鱼群落结构研究

湖口江段连通长江与鄱阳湖, 是诸多鱼类的洄游通道, 在长江鱼类的繁衍生息中发挥重要功能。研究于2016年5月—8月在长江中下游鱼类繁殖期内对湖口江段系统开展鱼类仔稚鱼资源的调查, 研究分析了该江段仔稚鱼群落组成、优势种、密度变化、时间空间分布及其与环境因子的关系。结果表明:88d连续采样共鉴定出隶属于8目12科39个仔稚鱼类群, 其中37个类群鉴定到种, 1个类群鉴定到亚科, 1个类群鉴定到科。贝氏?(Hemiculter bleekeri)为该江段仔稚鱼的第一优势种, 其余优势种有虾虎鱼科(Gobiidae)、鳊(Parabramis pekinensis)和飘鱼(Pseudolaubuca sinensis)。仔稚鱼密度在7月1日达到峰值, 峰值为1230.77 ind./100 m3; 7月1日至8月15日仔稚鱼密度整体呈波动性下降的趋势。时间尺度的聚类将6个时期分为5月下旬—7月上旬与7月下旬—8月上旬2个群组, 贝氏?、翘嘴鲌和刀鲚等在6月下旬达到峰值; 鳊、四大家鱼和鳜等在7月上旬达到峰值。江段断面上南北近岸采样点仔稚鱼密度高于断面中心。使用冗余分析方法(RDA)分析了仔稚鱼密度与环境因子的关系, 发现水温、透明度、流量均为影响仔稚鱼群落结构的主要环境因子。水位与仔稚鱼密度相关性分析表明, 两者呈极显著相关(P<0.01)。研究表明, 湖口江段鱼类早期资源较为丰富, 仔稚鱼群落结构主要以中小型鱼类为主, 且江湖洄游性鱼类占比较高; 仔稚鱼对各环境条件有着不同适应特点, 仔稚鱼与水温、透明度、流量均呈现出不同程度的相关关系。研究结果补充了湖口江段鱼类早期资源的基础资料, 为长江中下游鱼类资源保护策略的制定提供了科学依据。     

Distribution, endemism and threat status of freshwater fishes in the Western Ghats of India

Aim To study (1) the large-scale distribution patterns of freshwater fishes in the Western Ghats of India; (2) the endemism and uniqueness of the fishes in various zones; and (3) the threat status of fishes by categorizing them under low risk (LR), vulnerable (VU), endangered (EN) and critically endangered (CR). Location The Western Ghats of India. Methods The scientific literature describing the freshwater fishes of the Western Ghats was reviewed. Data describing the lists of the species were extracted and complied. The species accumulation curve was plotted using Michaelis–Menten-like equation. The Western Ghats was divided into six zones and similarity of the species was calculated using Jacquard's index. Results Literature to date records 288 species belonging to 12 orders, 41 families and 109 genera, of which 118 species are endemic and 51 are unique. However, the species accumulation curve shows that there might be 345 species in this region, indicating that 16% species have not been recorded to date. An analysis of the distribution pattern of fishes in the Western Ghats suggests that the southern region is more diverse than the northern and central regions. The southern region shows high endemism and high uniqueness while the northern region shows high endemism but less uniqueness. The similarity index between the zones indicates that as the distance between the zones increases similarity decreases. The status of 105 of 288 species was not known due to data deficiency but among the remaining 183 species, 58 species were categorized as LR, 41 as VU, 54 as EN, 24 as CR while the remaining six species were introduced. Conclusions The distribution patterns of fishes in the Western Ghats are discussed in accordance with the geography of Western Ghats, its climatic conditions and ‘Satpura Hypothesis’. The threat status of fishes found in Western Ghats suggests that at least 41% of fish fauna is threatened by either being VU, EN or CR. Implication of potent conservation measures is necessary to conserve the fish fauna of Western Ghats.     

泉州湾海域鱼类多样性及营养级变化

利用2008年5月和10月在泉州湾进行的拖网渔业资源调查资料, 探讨了该海域鱼类群落结构和物种多样性特征。结果表明, 两次拖网调查共鉴定鱼类54种, 隶属于2纲13目32科。其中中上层鱼类12种, 近底层鱼类19种, 底层鱼类23种; 暖水性鱼类40种, 暖温性鱼类14种, 未发现冷温性和冷水性种类; 杂食性鱼类4种, 低级肉食性鱼类37种, 中级肉食性鱼类8种, 高级肉食性鱼类5种。白姑鱼(Argyrosomus argentatus)和叫姑鱼(Johnius belengerii)是5月份最主要的优势种, 凤鲚(Coilia mystus)和龙头鱼(Harpodon nehereus)是10月份最主要的优势种。与1985年的调查资料相比, 泉州湾鱼类组成和优势种发生了很大的变化, 多样性指数由3.05下降到2.32, 均匀度指数由0.76下降到0.58, 营养级指数由2.79下降到2.54。泉州湾鱼类多样性下降的主要原因可能是过度捕捞、水域污染和栖息地丧失等。     

Symbiotic microflora in fishes of different ecological groups

Published data on the taxonomic composition of the intestinal bacterial flora in fishes living under different conditions (marine and freshwater fishes) and differing in the type of feeding are reviewed. The results confirm the conclusion that the composition of intestinal microflora differs depending on fish ecology. A limited number of bacterial taxa found in the intestines of some fish species may be evidence not only for a low diversity of these bacteria but also for insufficient knowledge about them. Considerable differences in the composition of intestinal microflora in marine and freshwater fishes are described.     

繁殖期4种淡水鱼类化学预警行为及其与性腺指数的关联

化学预警信息（Chemical alarm cue,CAC）在鱼类捕食者-猎物关系中发挥重要作用,并与二者生存适合度密切关联。繁殖期鱼类的繁殖生理投入和化学预警响应均具有较高的能量需求,因而可能存在某种程度上的生存-繁殖的权衡（Trade-off）。选取高体鳑鲏（Rhodeus ocellatus,卵生,繁殖投入较低）、斑马鱼（Danio rerio,卵生,繁殖投入较高）、孔雀鱼（Poecilia reticulata,卵胎生,繁殖投入较高）和皮球鱼（Poecilia latipinna,卵胎生,繁殖投入很高）等繁殖方式各异、能量投入不同的4种淡水鱼类为实验对象,测定了繁殖IV期实验鱼对不同浓度的化学预警信息（Damage-released chemical alarm cues,DCAC）的行为响应模式,并探究了4种实验鱼的化学预警响应与其性腺指数（Gonadosomatic index,GSI）的关联。结果表明：（1）DCAC对4种实验鱼的空间分布、活跃状态、逃逸行为等大部分化学预警响应参数均有不同程度的影响（P<0.05）;（2）4种实验鱼GSI与其化学预警响应参数的变化无显著相关性（P>0.05）（除高浓度DCAC处理组皮球鱼GSI与底栖时间的变化负相关外）。研究回答了长期以来有关繁殖期鱼类化学预警通讯是否缺失的问题,证实了繁殖期不同繁殖生理投入/繁殖对策的4种淡水鱼类均有显著的化学预警响应,提示鱼类GSI与其化学预警响应程度通常不相关（仅高风险环境下繁殖生理投入很高的物种中可能呈现负相关）。     

中国非人灵长类物种的行为偏侧研究进展

行为偏侧是指动物进行某一行为时偏好使用某一侧肢体或感觉器官。行为偏侧作为脑偏侧所对应的可观测的行为指标,是动物行为适应性进化的代表性特征之一,它在个体水平上影响着个体适合度,在群体水平上是社会性物种的一种进化稳定策略,具有重要的生态和进化意义。中国非人灵长类资源丰富,而中国非人灵长类的行为偏侧研究起步较晚,始于二十世纪八十年代。本文系统归纳中国非人灵长类物种的行为偏侧研究进展,并基于当前研究现状,为今后发展提出积极建议。     

马鞍列岛多种生境中鱼类群聚的昼夜变化

为了解岛礁水域鱼类群聚的昼夜变化特征,以便更全面地设计采样方法和掌握采样的时间尺度,于2009年9月对马鞍列岛7种生境进行了共计24网次的刺网昼夜采样,结合排序和聚类方法,从种类组成、相对生物量和丰度、种类丰富度、多样性和相似性等方面对研究海域鱼类群聚特征的昼夜变化作了探讨.在采获的55种鱼类中,昼夜出现的分别为41和46种,数量差别不大,但其昼夜组成却随栖息水层的变化而不同,底层鱼类更趋向于夜间在硬相生境集群活动;近底层鱼类的昼夜集群随生境变化而变化,在同一生境中既有偏向白天也有趋向夜间的;中上层鱼类更多地出现在白天的人工生境(AH).AH白天的丰度渔获率显著大于晚上,而天然生境(NH)昼夜差别不大;生物量渔获率无论NH还是AH皆无显著昼夜差异.具体到种类,仅有小黄鱼Larimichthys polyactis和赤鼻棱鳗Thryssa kammalensis等少数种类的数量在AH有显著的昼夜差别,其他多数种类虽然昼夜的出现率大多有别,但渔获率昼夜差异皆不明显.多样性差异更多的表现在不同生境之间,而同一生境的昼夜差异往往不甚显著.各个生境中鱼类的昼夜种类交替现象非常明显,形成了以褐菖(鲐)Sebastiscus marmoratus和鳗鲇Plotosus anguillaris为代表的夜间优势类群为主的硬相生境群聚格局、以丝背细鳞鲀Stephanolepis cirrhifer和细刺鱼Microcanthus strigatus为代表的白天优势类群为主的硬相生境群聚格局以及缺乏底层优势类群、以石首鱼科鱼类为代表的近底层鱼类为绝对优势类群的软相生境群聚格局.因此,采用被动性渔具在近岸典型生境进行鱼类等相关生物调查时,应使采样时间覆盖昼夜两个时段,且至少保证24h.     

Host preference and specialization in Gnathia sp., a common parasitic isopod of coral reef fishes

A gnathiid species (Crustacea: Isopoda; one of the most common ectoparasites of coral reef fishes) from the Great Barrier Reef, Australia, was allowed to choose among fishes from three different families to feed on (using two species of fishes per family). Gnathiids showed a strong preference for labrids, rarely feeding on pomacentrids or apogonids. In a separate experiment, gnathiid host preference did not vary among three labrid fish species. Gnathiids that fed on labrids had higher survival than those that fed on apogonids. Male gnathiids that fed on labrids also moulted to the adult stage more quickly. This suggests that host specialization and local adaptation might be occurring between these ectoparasites and their host fishes at the host fish family level.     

黄河流域淡水鱼类多样性和保护

本文介绍了黄河流域鱼类研究的历史、淡水鱼类的物种组成、整体分布格局、特有性、濒危性, 以及鱼类多样性在黄河上、中、下游等的特点。历史上对于黄河鱼类多样性的研究, 历经了四个阶段, 从最初的零星记录一直到现阶段的深入研究。综合历史记录和野外调查, 已知黄河流域分布的淡水鱼类共计147种, 隶属于12目21科78属, 其中鲤形目种类占据绝对优势。另外, 全流域黄河特有种计有27种, 受危物种24种, 分别占总数的18.37%和16.32%。同中国主要江河相比, 黄河鱼类在高级分类阶元上的多样性较高, 但物种多样性则处在较低水平; 尽管黄河特有鱼类和受危物种比例低于全国平均水平, 但上游特有鱼类和珍稀濒危鱼类的占比很高。目前黄河鱼类多样性大幅降低, 现状调查仅能采获历史记录种类的53.06%。梯级水电开发、水资源过度利用、外来物种、水域污染和过度捕捞都是威胁鱼类多样性的重要因素, 但对各河段和支流的影响不一, 应做出有针对性的保护部署。