Length-weight relationship and condition factor of common minnow, Esomus danricus (Ham.) from different freshwater environments.

Investigations were made on the length-weight relationship and condition factor of Esomu danricus (Ham) from ponds and flowing water channels. These relationships could be represented by the regression equations, log W = -2.6252 + 3.2451 log L (for channel fishes) and log W = -1.5390 + 2.6318 log L (for pond fishes). The correlations were significantly high (P < 0.001). The mean values of condition factors were 0.529 and 0.713 for pond and channel fishes, respectively. The additive action of various factors in stagnant ponds, such as oxygen deficiency, stratification of indispensahle nutrients at the bottom, accumulation of body wastes of fishes, and unoxidized chemical compounds, competition for many necessities of life as space, food, shelter, seemed to adversely affect the growth rate and condition factor of pond dwelling fishes. Contrary to this the circulation of water induced by currents in the channels appeared to cause mixing of water at all depths to even out differences in dissolved oxygen concentration, temperature, nutrients, besides minimizing the effect of repressive factor. Such conditions invariably offered more opportunities to fishes to conserve almost all the available space and other resources in the habitat. This ensured rapid growth as evidenced by higher condition factor of the flowing-water fishes as compared to their counterparts occurring in ponds.     

Ontogenetic features of Luciocephalus (Perciformes, Anabantoidei) with a revised hypothesis of anabantoid intrarelationships

The anatomy of the anabantoid fish Luciocephalus is reinvestigated and the ontogeny of certain character complexes is described for the first time. Luciocephalus possesses the following previously unrecognized or equivocally interpreted anatomical characters: a clearly separate ectopterygoid bone, pharyngeal processes of the basioccipital, a toothless pharyngeal process of the parasphenoid, an infrapharyngobranchial I and an endoskeletal mental ossification. In addition, aspects of the ontogeny of the hyopalatine arch in the belontiids Belontia, Trichogaster and Ctenops are described. Species of these three genera all possess an ectopterygoid bone previously thought to be lacking in the family Belontiidae. The significance of the results for reconstructing interrelationships of the anabantoid families and the phylogenetic position of Luciocephalus is discussed. A revised hypothesis of anabantoid intrarelationships is presented. Four synapomorphic characters indicate that Luciocephalus is more closely related to the Belontiidae (including Osphronemus) rather than forming the sister group of all other anabantoids.     

博斯腾湖鱼类资源组成、体长与体重关系及生长状况

博斯腾湖为西北高原地区湖泊,1958年开始商业化渔业生产,1962年开始鱼类引种工作,半个多世纪以来湖区鱼类资源组成处于不断的变动当中。本文围绕湖区鱼类群落组成动态、当前鱼类的体长与体重关系及种群生长状况开展研究,于2019年春季(4月)、夏季(8月)、秋季(10月),通过渔具采样和渔获物调查相结合的方法,在博斯腾湖共发现鱼类17种,隶属于4目8科,其中?(Hemiculter leucisculus)、池沼公鱼(Hypomesus olidus)、鲫(Carassius auratus)为优势种,鱼类资源结构小型化问题严重。描述了15种鱼类体长-体重关系与生长情况,其中12种鱼类为正异速生长,3种鱼类为负异速生长,优势鱼类的体长-体重关系式参数b值范围2. 95～3. 56,决定系数r2值范围0. 874～0. 997。本研究所得结果可为博斯腾湖鱼类资源保护与可持续利用提供基础资料和科学支撑。     

Integrating spatial and temporal variability into the analysis of fish food web linkages in Tijuana Estuary

Our understanding of fish feeding interactions at Tijuana Estuary was improved by incorporating estimates of spatial and temporal variability into diet analyses. We examined the stomach contents of 7 dominant species (n=579 total fish) collected between 1994 and 1999. General feeding patterns pooled over time produced a basic food web consisting of 3 major trophic levels: (1) primary consumers (Atherinops affinis, Mugil cephalus) that ingested substantial amounts of plant material and detritus; (2) benthic carnivores (Clevelandia ios, Hypsopsetta guttulata, Gillichthys mirabilis, and Fundulus parvipinnis) that ingested high numbers of calanoid copepods and exotic amphipods (Grandidierella japonica); and (3) piscivores (Paralichthys californicus and Leptocottus armatus) that often preyed on smaller gobiids. Similarity-based groupings of individual species' diets were identified using nonmetric multidimensional scaling to characterize their variability within and between species, and in space and time. This allowed us identify major dietary shifts and recognize events (i.e., modified prey abundance during 1997–98 El Ni no floods) that likely caused these shifts.     

季德胜蛇药治疗黄蜂蛰伤的疗效观察

目的观察季德胜蛇药对黄蜂蛰伤的治疗效果。方法将200例黄蜂蛰伤患者随机分为两组,其中对照组的100例患者给予常规西医治疗,治疗组100例患者给予中成药季德胜蛇药联合常规西医治疗,两组患者均治疗3天进行临床疗效比较。结果两组疗效比较,治疗组的痊愈率为92%,明显高于对照组的71%,差异有统计学意义(P0.05)。结论季德胜蛇药有助于缓解黄蜂蜇伤患者的临床症状。     

“Length weight relationship of four non commercial fish species from the Southwest coast of India”

Length weight relationships (LWRs) were estimated for four species of low value fishes that belongs to four families from the southwest coast of India. The specimens of, Callionymus margaretae, Dactyloptena peterseni, Rogadius serratus and Minous inermis were collected for a period of 1 year from the fishing trawlers of Cochin Fisheries Harbour (Lat. 09° 56′ 327″ N, Long. 76° 15′ 764″ E). The estimated allometric coefficient b values ranged from 2.5020 (Rogadius serratus) to 3.2438 (Dactyloptena peterseni) and r² values ranged from 0.9492 (Rogadius serratus) to 0.9869 (Dactyloptena peterseni). All the LWRs were highly significant, with p < .001.This study provides the first estimate of LWRs for these low value by catch fish species.     

达氏鲟生物学特性及人工繁殖技术研究

为科学评估长江上游长江鲟增殖放流效果, 研究基于2021—2023年宜宾、泸州和合江3个江段渔业监测数据, 对长江上游长江鲟野外种群恢复情况进行了分析。监测期间, 3个江段共采集长江鲟849尾, 其体长分布为14.70—93.00 cm [平均体长(45.19±14.01) cm], 优势组体长为25.10—65.00 cm, 占总体的88.98%; 体重分布为24.0—6850.0 g [平均体重(892.7±960.8) g], 优势组体重为0—1250.0 g, 占总体的83.18%。分析显示: (1) 2022年和2023年监测到的长江鲟体长、体重均值均显著高于2021 年(P<0.05), 体长均值均高于当年放流群体体长均值; (2)监测的长江鲟群体呈正异速生长, 体重增长速率大于体长增长速率, 且宜宾至合江江段的生长条件因子、异速生长参数具有明显的地点和时间差异(P<0.05); (3)长江鲟单位捕捞努力量渔获量为0.1—35.0 ind./(net·d), 不同季节间呈显著差异(P<0.05); (4)在2018—2023年各大单位加大放流力度且2021年长江十年禁捕政策出台并执行后, 2021—2023年监测期间长江鲟采集数量明显增加。研究结果表明, 禁捕后长江上游长江鲟资源正逐渐恢复, 且生长状况良好, 增殖放流效果初步显现。

     

怒江云南段鱼类多样性现状与威胁因子

怒江是中国西南地区重要的国际河流, 是云南六大水系之一。为了解怒江云南段的鱼类多样性现状及受威胁因素, 本研究于2019-2020年对怒江云南段的干流及其支流的53个采样点进行了系统的调查, 并对该流域的鱼类多样性和威胁因子进行了分析。结果表明, 怒江云南段共记录鱼类9目26科59属89种, 本研究采集到鱼类6目20科42属51种。相对重要性指数分析发现, 怒江云南段优势种为密带南鳅(Schistura poculi), 且指数得分远远高于其他鱼类。物种多样性指数表明, 怒江云南段 Shannon-Wiener多样性指数、Margalef物种丰富度指数、Simpson优势度指数、Pielou均匀度指数分别为2.10、5.91、0.71、0.53; 怒江干流以及两条较大支流罗明坝河和勐波罗河鱼类多样性较高。相似度分析发现, 怒江云南段各河段或河流鱼类组成差异较大。通过Pheatmap对威胁因子分析, 结果显示对怒江云南段鱼类多样性的主要威胁因素依次为农业/生活垃圾污染、捕捞、外来种入侵和支流水利水电工程建设。