红鳍笛鲷仔、稚鱼异速生长

运用生态学和传统理论生物学的研究方法,对孵化后红鳍笛鲷（Lutjanus erythropterus）仔、稚鱼在早期生存和环境适应上的异速生长及器官优先发育生态学意义进行了研究,以期为红鳍笛鲷人工繁殖、育苗提供参考资料。以17日龄为红鳍笛鲷仔、稚鱼的区分时期,结果表明,红鳍笛鲷仔、稚鱼的感觉、呼吸摄食和游泳等器官快速分化,均存在异速生长现象。在头部器官中,吻长、口宽、眼径和头高在仔鱼期均为正异速生长,稚鱼期吻长为等速生长,口宽、眼径和头高为负异速生长。在身体各部位中,仔鱼期头长和体高为正异速生长,躯干部和尾长为负异速生长;稚鱼期体高和躯干长为正异速生长,头长和尾长为等速生长;在游泳器官中,仔鱼期红鳍笛鲷背鳍、腹鳍、尾鳍为正异速生长,胸鳍为等速生长,稚鱼期臀鳍为正异速生长,腹鳍、胸鳍和尾鳍为等速生长,背鳍为负异速生长。红鳍笛鲷这些关键器官的快速发育,使外源性营养开始后以最小的代谢损耗获得了生存能力的显著提升,对挑战和适应纷繁变换的外界压力具有重要的生态学意义。     

大麻哈鱼卵黄囊期仔鱼异速生长及其生态学意义

运用实验生态学的方法, 对大麻哈鱼(Oncorhynchus keta Walbaum)卵黄囊期仔鱼的异速生长及器官优先发育在早期生存和环境适应上的生态学意义进行了研究。结果表明, 大麻哈鱼卵黄囊期仔鱼的感觉、摄食, 呼吸和游泳等器官快速分化, 许多关键器官均存在异速生长现象。在身体各部分中, 头部和尾部为正异速生长, 躯干部为负异速生长, 体高有先增大后减小的趋势; 在头部器官中, 眼径、口宽、吻长和眼后头长均为正异速生长; 在游泳器官中, 胸鳍、腹鳍、背鳍、臀鳍、背鳍基、臀鳍基和尾鳍均为正异速生长, 脂鳍为负异速生长, 其中, 腹鳍在全长25.31 mm、12日龄出现生长拐点, 但拐点前后均为正异速生长。大麻哈鱼卵黄囊期仔鱼感觉、摄食, 呼吸和游泳等器官的快速发育, 使出膜后的仔鱼在最短的时间内获得了与早期生存密切相关的各种能力, 对适应复杂多变的外界环境具有重要的生态学意义。       

斑鰶仔、稚鱼形态发育及异速生长模式研究

运用光学显微镜技术和实验生态学方法, 对斑鰶(Konosirus punctatus)早期形态发育观察、异速生长模式及其生态学意义进行了研究。结果表明: 在水温(21.5±0.5)℃下, 初孵仔鱼全长(3.18±0.52) mm, 斑鰶仔鱼期从孵化出膜到43日龄棱鳞开始出现前, 稚鱼期从44日龄棱鳞出现到55日龄全身覆满鳞片。斑鰶的形态变化和器官分化主要发生在仔鱼期。斑鰶的吻长、躯干长、肠道长、胸鳍长、腹鳍长等重要形态学指标均存在异速生长现象, 其生长拐点依次为 42日龄(TL: 26.41 mm)、24日龄(TL: 15.57 mm)、31日龄(TL: 21.41 mm)、41日龄(TL: 25.47 mm)、42日龄(TL: 26.41 mm)。相对于全长、吻长和胸鳍长在拐点前后由正异速生长变为等速生长, 腹鳍长由正异速生长转为负异速生长, 这为呼吸、摄食和成功逃避捕食者提供有利条件; 而肠道长由负异速生长变为等速生长, 这可能与斑鰶的食性转化有关。综上所述, 为适应复杂多变的生存环境, 斑鰶在早期发育阶段优先发育对生长生存起关键作用的器官, 这对提高仔、稚鱼的存活率具有重要的生态学意义。研究将为今后进一步人工繁育和苗种培育提供理论依据。     

日本七鳃鳗胚胎发育及卵黄囊期仔鱼的异速生长

通过观察日本七鳃鳗Lampetra japonica (Martens, 1868)胚胎外部形态和内部组织结构变化, 描述受精卵从卵裂至器官形成以及仔鱼孵出的发育阶段, 采用实验生态学方法研究卵黄囊期仔鱼的异速生长模式。结果表明: 日本七鳃鳗卵子为乳白色, 呈卵圆形; 受精卵卵裂方式为全卵裂; 胚胎发育过程主要包括卵裂期、囊胚期、原肠胚期、神经胚期、头凸期、孵出前期和孵出期, 历时11—12d; 初孵仔鱼为乳白色, 全长约(3.41±0.24) mm, 体质量约为0.0006 g。日本七鳃鳗胚胎发育研究可为了解七鳃鳗胚胎发育过程, 早期脊椎动物的起源和发育进化研究提供参考。卵黄囊期内仔鱼身体各部分中, 头长和尾长均表现出快速生长, 同在7 日龄出现生长拐点, 且生长拐点后的生长速率都大于生长拐点前的生长速率; 而仔鱼体长在卵黄囊期内表现出慢速生长。在头部器官中, 吻长、鳃前长和鳃长均表现出快速生长现象, 吻长和鳃长分别在9日龄和8日龄出现生长拐点; 口笠长在3日龄时出现生长拐点, 在生长拐点前为等速生长, 而在生长拐点后表现出快速生长; 眼径和眼鳃间距则分别表现出等速生长和慢速生长。泄殖孔在卵黄囊期内未出现生长拐点, 生长速率相对于全长生长速率表现出快速生长现象。七鳃鳗卵黄囊期仔鱼的异速生长是在长期进化过程中, 适应早期生活环境和独特的生活方式而形成特有的发育机制。     

鲈鲤仔鱼的异速生长模式

采用实验生态学方法研究了鲈鲤(Percocypris pingi pingi)仔鱼(0～57日龄)的异速生长模式.结果显示:鲈鲤仔鱼全长由慢速生长到快速生长的转折点为25日龄;其多数外部器官均具有异速生长特点,头部和尾部的生长快于躯干部,均在22 ～ 27日龄出现生长拐点;眼径在14 ～ 15日龄较早出现生长拐点,促使眼睛充分发育,以提高早期仔鱼开口期摄食外源食物的能力;吻长在33～34日龄出现生长拐点,促进了口的充分发育,以适应不同的饵料环境;胸鳍、背鳍、尾鳍、臀鳍和腹鳍分别在13～14日龄、31～32日龄、32 ～33日龄、38 ～39日龄、43 ～ 44日龄出现生长拐点,除胸鳍和尾鳍外,其余各鳍的鳍条均在拐点处分化完全,即鲈鲤仔鱼的游泳能力已得到大幅提高.研究表明,鲈鲤仔鱼的异速生长模式,保证了各重要功能器官的充分发育,以适应多变的环境,有效地保障了其早期的生存,可为育苗生产和野生早期资源的保护提供技术支撑.     

东海南部竹筴鱼形态特征参数及其相关性比较分析

2012年4月采集东海南部水域100尾竹筴鱼样本,测量其体长、全长、头长、头高、体高、体厚、吻长、眼径、眼后头长、尾柄长、尾柄高、体重等共12个形态特征指标.采用方差分析、偏相关分析、通径分析及回归分析,研究竹筴鱼东海南部种群各形态特征参数间的相关关系,确定与竹筴鱼体重显著相关的主要形态特征参数.结果表明:东海南部竹筴鱼的头长、头高、体厚、吻长、眼径、眼后头长、尾柄高、体重与体长呈指数相关(P＜0.01);而全长、体高、尾柄长则与体长呈线性相关(P＜0.01).竹筴鱼体长和体重的拟合方程为:y=0.0185x28736 (R2=0.9714);竹筴鱼的b值为2.8736,小于3,为负异速增长,即体长的增长速度要高于体重.头长、头高、体高、眼后头长、尾柄高对竹筴鱼体质量的影响存在显著关系;对竹筴鱼体质量的直接作用影响大小依次为:头长(0.242**)＞尾柄高(0.223**)＞头高(0.197**)＞眼后头长(0.161**)＞体高(0.155**),建立了竹筴鱼体质量的最优回归数学模型:y=-46.845 +3.892x1+9.623 x2+ 12.354x3+7.128x4+ 8.361x5.     

施氏鲟仔鱼发育及异速生长模型

施氏鲟仔鱼的生长发育可分为两个时期:卵黄囊期(或称为自由胚期),即从刚出膜(0日龄,10.17±0.63 mm)到初次开口(9日龄,18.93±0.74 mm);晚期,从开口摄食至器官发育基本完全(38日龄,41.89±5.09 mm).卵黄囊期仔鱼的感觉、摄食、呼吸、游泳等器官快速分化;晚期仔鱼各骨板分化并发育,在形态上逐渐完成向成鱼的转变.对施氏鲟仔鱼异速生长进行的研究表明,仔鱼许多关键器官均存在异速生长现象,如眼径、口宽、尾鳍长、胸鳍长分别在2日龄、8～9日龄、10日龄、11日龄出现生长拐点,拐点之前器官快速生长,拐点之后生长速度减慢甚至近似等速生长.施氏鲟仔鱼各器官呈现出协调和快速发育的特征,随着重要的感觉、摄食、呼吸、游泳等器官的发育和完善,仔鱼快速地具备了躲避敌害和摄食的能力,其生存能力大大提高.     

施氏鲟仔鱼发育圾异速生长模型

施氏鲟仔鱼的生长发育可分为两个时期:卵黄囊期(或称为自由胚期),即从刚出膜(0日龄,10.17±0.63 mm)到初次开口(9日龄,18.93±0.74 mm);晚期,从开口摄食至器官发育基本完全(38日龄,41.89±5.09 mm).卵黄囊期仔鱼的感觉、摄食、呼吸、游泳等器官快速分化;晚期仔鱼各骨板分化并发育,在形态上逐渐完成向成鱼的转变.对施氏鲟仔鱼异速生长进行的研究表明,仔鱼许多关键器官均存在异速生长现象,如眼径、口宽、尾鳍长、胸鳍长分别在2日龄、8~9日龄、10日龄、11日龄出现生长拐点,拐点之前器官快速生长,拐点之后生长速度减慢甚至近似等速生长.施氏鲟仔鱼各器官呈现出协调和快速发育的特征,随着重要的感觉、摄食、呼吸、游泳等器官的发育和完善,仔鱼快速地具备了躲避敌害和摄食的能力,其生存能力大大提高.     

拟赤梢鱼的胚胎发育和仔稚鱼生长特性观察

为阐明拟赤梢鱼(Pseudaspius leptocephalus)胚胎发育和仔稚鱼发育特点, 采用人工催产的方式获得受精卵, 观察分析了拟赤梢鱼胚胎发育和仔稚发育的时序特征。结果表明: 拟赤梢鱼成熟卵粒为黄色圆球形, 平均卵径为(1.77±0.20) mm, 遇水具微黏性; 在水温23℃条件下, 胚胎发育经历合子期、卵裂期、囊胚期、原肠胚期、神经胚期、器官形成期和孵化出膜期7个阶段26个时期, 共历时47h 55min完成孵化过程。初孵仔鱼在(23±1)℃水温条件下, 经历卵黄囊期仔鱼(0—7d)、晚期仔鱼(8—26d)和稚鱼期(27—31d), 进入幼鱼期; 卵黄囊期仔鱼游泳能力差, 随着卵黄囊逐渐消耗, 体表色素斑、胸鳍和尾鳍等逐渐形成, 消化道贯通, 鳔充气; 晚期仔鱼卵黄囊完全消失, 仔鱼游泳能力增强, 开口摄食, 腹鳍形成, 皮肤透明; 稚鱼期鳞片形成并覆盖全身, 鱼体形态已逐渐与成鱼无异。拟赤梢鱼仔稚鱼阶段全长生长特性公式为TL=0.0125x2+0.3579x+6.2058 (R2=0.9953), 出膜15d内, 仔鱼生长速度缓慢, 全长日生长率仅为(0.38±0.02) mm/d, 15d后, 仔鱼生长速度变快, 全长日生长率可达(1.24±0.09) mm/d。研究初步阐明了拟赤梢鱼的胚胎发育和仔稚鱼发育的时序特征, 为拟赤梢鱼的苗种规模化繁育提供了理论基础。     

广西华缨鱼属鱼类一新种记述

在整理华缨鱼属标本时发现,1993年9月在广西壮族自治区天峨县红水河水系地下河采集到的一批标本为一个未经发表的新种,新种订名为大眼华缨鱼(Sinocrossocheilus megalophthalmus)。其下咽齿2行,可与下咽齿3行的7种华缨鱼相区别,而与属内同样具2行下咽齿的贵州华缨鱼(S.guizhouensis)、小口华缨鱼(S.microstomatus)和宽唇华缨鱼(S.labiatus)亲缘关系较近。但:(1)新种胸鳍中点上方无黑斑,背鳍分枝鳍条7,腹鳍分枝鳍条7,背鳍前鳞15—16,眼大,头长为眼径2·5—3·1倍,眼径为头宽44·7%—57·8%,吻须后伸至前后鼻孔之间或眼前缘,口角须后伸至眼前缘至眼中之间或眼中至眼后缘之间,体长为尾柄高8·9—10·7倍,头长为吻长2·5—3·7倍,可与贵州华缨鱼(胸鳍中点上方有一明显黑斑,背鳍分枝鳍条8,腹鳍分枝鳍条8,背鳍前鳞12—14,头长为眼径4·0—5·0倍,眼径为头宽16·6%—20·7%,吻须后伸不达后鼻孔后缘,口角须后伸至眼前缘,体长为尾柄高7·2—8·2倍,头长为吻长1·9—2·2倍)相区别;(2)新种背鳍前鳞15—16,侧线鳞39—40,侧线上鳞4·5—5·5,背鳍分枝鳍条7,鳃耙13,腹鳍末端伸达肛门,眼径为头宽44·7%—57·8%,可与宽唇华缨鱼(背鳍前鳞22,侧线鳞42—45,侧线上鳞6·5,背鳍分枝鳍条8,鳃耙10,腹鳍末端不达肛门,眼径为头宽23·3%—30·0%)相区别;(3)新种与同水系的小口华缨鱼在鳍条数、侧线鳞、体色、斑纹等方面最为相似,但新种围尾柄鳞14/16,眼大,头长为眼径2·5—3·1倍,腹鳍末端伸达肛门,口角须后伸至眼前缘至眼中之间或眼中至眼后缘之间,吻皮边缘深裂成小穗,背鳍起点距吻端较距尾鳍基为近,背鳍长大于头长,体长为尾柄长4·8—5·9倍,头长为吻长2·5—3·7倍,尾柄长为尾柄高1·6—2·1倍,可与之(围尾柄鳞12,眼小,头为眼径4·4—4·6倍,腹鳍末端不达肛门,口角须伸达眼下方,吻皮边缘不开裂或开裂不明显,背鳍起点距吻端等于距尾鳍基,背鳍条约等于头长,体长为尾柄长6·1—6·4倍,头长为吻长2·1—2·4倍,尾柄长为尾柄高1·4—1·5倍)相区别。     

Ontogenetic development,allometric growth patterns,and daily increment validation of larvae and juvenile Culter alburnus

Fish ontogeny, allometric growth patterns, and otolith microstructure are fundamental in aquaculture and essential for understanding the early-life ecology of fish. Culter alburnus is a commercially important fish species and an excellent breeding target for aquaculture. In this study, newly hatched C. alburnus larvae were reared to the juvenile stage in a hatchery. Three days post hatch, the eyes, mouth, and intestine had developed, and the larval yolk sac had been completely absorbed. Fin rays started to differentiate in the flexion stage and were fully developed by the postflexion stage. Pigmentations were well developed in the juveniles. Culter alburnus larvae were characterized by 39–43 myomeres and 23–25 anal fin rays, swim bladder shape, and pigmentation. Head length, height, and musculature height showed positive allometric growth patterns, suggesting that head and trunk growth was prioritized. Positive allometric growth of the tail was simultaneous with the formation of fins, suggesting that swimming mode transformation, diet changes, and habitat shifts occurred after the start of the postflexion stage. Otolith growth increments in both the sagittae and lapilli were deposited daily, with the first increment formed on day 1 on the sagittae and day 4 of yolk sac absorption on the lapilli. Increments were thin and faint during the early developmental stage, gradually increasing to reach the broadest widths and the strongest contrast at the postflexion stage, which may be related to habitat shifts. This information will assist in the breeding and hatchery production of C. alburnus and establish suitable methods for analyzing this species’ spatiotemporal distributions and early-life traits.

     

棒花鱼形态特征的两性异形和雌性个体生育力

测定了棒花鱼(Abbottina rivularis)繁殖期形态特征包括体长、头长、头宽、头高、眼间距、鼻间距、背鳍基长、胸鳍长、胸鳍腹鳍间距、尾柄长、尾鳍长和体重的两性异形和雌性个体生育力。结果表明,雄性个体的数量显著多于雌性个体,雄性个体的体长显著大于雌性个体。特定体长的雌性个体的胸鳍腹鳍间距显著大于雄性个体,头长、头宽、头高、眼间距、鼻间距、背鳍基长、胸鳍长、尾柄长和尾鳍长显著小于雄性个体,雌雄两性体重不存在显著差异。棒花鱼的怀卵数量与体长和体重回归关系显著。偏相关分析显示,当控制第三者恒定时,怀卵数量与体长和体重呈正相关但不显著。棒花鱼存在个体大小和其他局部特征显著的两性异形,雌性个体主要通过腹腔容积的增加提高个体生育力。棒花鱼形态特征的两性异形是性选择和生育力选择共同作用的结果。     

Characterization of the initial ontogeny of Leiarius marmoratus (GILL, 1870): larvae to juvenile

Aiming to provide data on the biology of Leiarius marmoratus, which will aid in its production in captivity, as well as in studies for its preservation in the environment, this work had as objectives: analyze and describe main morphological alterations during larval ontogeny of the species. We analyzed 205 individuals, obtained by induced reproduction (Colpani Pisciculture) and kept in CEPTA/ICMBIO, Pirassununga, São Paulo, Brazil. Analyses were performed from hatching moment to 30th day. The specimens were classified into two periods: larval (Stages: vitelline, pre‐flexion, flexion, post‐flexion) and juvenile. Hatched larvae showed ident chromatophores only at anterior and posterior extremities of yolk sac. The standard length ranged from 2.16 mm (yolk) to 28.84 mm (Youth). Dorsal fin rays were initially observed at flexion stage (12–14 rays). Major alterations occurred during post‐flexion/juvenile stage, when dorsal, pectoral, pelvic, anal, and caudal fins were observed and pigmentation intensified throughout the lateral region, forming bands in the body, one between the end of the head and beginning of dorsal to pelvic fin, and another one beginning at dorsal to caudal peduncle and four longitudinal at the head.     

Morphological variations in bluegill, Lepomis macrochirus, with particular emphasis on growth-related changes

Morphological variations in bluegill, Lepomis macrochirus, including growth-related changes, sexual dimorphism and morphological differences between populations in different habitats, were examined in samples from three reservoirs in Kagawa, Japan. Body measurements demonstrated frequent growth-related proportional changes, particularly in body depth, body width, caudal peduncle length and head length, which all showed relative increases, whereas first dorsal fin length, caudal fin length and orbital diameter became relatively shorter. Body weight increased relatively with growth, with relative growth coefficients of 3.339–3.454 for regressions between total length and body weight. Such body weight increases were likely due to the relative increases in body depth and width, and caudal peduncle depth. Although counts of fin spines, fin rays and gill rakers did not change with growth, those of scales tended to increase. Males were significantly larger than females in body depth, caudal peduncle length, head length and body weight. Sexual dimorphism was also apparent in body coloration during the breeding season. In addition, a number of morphological differences were observed between individuals from different habitats.