Growth of red gurnard (Teleostei: Triglidae) from Pegasus bay,Canterbury, New Zealand

Growth of the red gurnard, Chelidonichthys kumu (Lesson and Garnot), from Pegasus Bay, Canterbury, was measured during 1966–67. Otoliths were used as an indicator of fish growth; mean length‐at‐age data were obtained from back‐calculated fish lengths at the time of formation of successive annual rings in the otoliths. Growth in length was found to be adequately expressed by the von Bertalanffy growth equation :

l_t = 52.0 [1 ‐ e‐^{0.406 (t‐o.291)}]

(where l_t is the fork length in cm at age t). The length: weight relationship was:

w = 78.56 × 10^‐4 l ^3.072

(where w is the weight in grams). From this relationship, growth in weight was described by the equation:

w_t = 1469 [1 ‐ e‐0.406 (t‐0.291)]³.     

The food and feeding of seven fish species from the Campbell Plateau,New Zealand

The food and feeding habits of hoki (Macruronus novaezelandiae), southern blue whiting (Micromesistius australis), javelin fish (Lepi‐dorhynchus denticulatus), ling (Genypterus blacodes), smooth rattail (Coelorinchus aspercephalus), silverside (Argentina elongata), and small‐scaled notothenid (Notothenia microlepidota) sampled from the Campbell Plateau in 1979 were examined. The importance of prey items in the diet has been assessed by an ‘index of relative importance’, which combines measurements of frequency of occurrence, number, and weight of prey. Hoki, southern blue whiting, and javelin fish are pelagic feeders. Hoki preyed largely on natant decapod crustaceans, amphipods, and myctophid and photichthyid fishes. The main prey of southern blue whiting were amphipods, natant decapods, and euphausiids. Javelin fish fed on natant decapods, amphipods, and small squid. Seasonal and regional differences in feeding, and dietary changes with length of fish were evident. Ling, smooth rattail, silverside, and small‐scaled notothenid are predominantly benthic feeders. Ling preyed on natant decapods, macrourid fishes, and small hoki. The diet of rattail comprised natant decapod crustaceans, opal fishes (Hemerocoetes spp.), and poly‐chaetes. Silverside fed almost solely on salps. Salps, amphipods, brachyuran crustaceans, and opal fishes were the main prey of small‐scaled notothenid.     

锯齿溪蟹(POTAMON DENTICULATUS)心肌细胞的超微结构观察

用透射电镜观察,发现锯齿溪蟹心肌细胞属横纹肌。粗丝和细丝排列成明带和暗带相间的横纹,每一条粗丝周围有6条细丝组成一个规则的6边形图案,但粗丝是中空的,细丝则是实心结构,且肌原纤维在心肌细胞体积中所占比例较少,线粒体的嵴较短,线粒体排列疏松。心肌细胞之间没有形成象脊椎动物那样的闰盘结构,因此,这些好构就造成了锯齿溪蟹的心脏功能比较低等。     

养殖条件下倒刺鲃的年龄与生长

研究了倒刺的年龄与生长规律 ,结果表明 :倒刺鳞片年轮特征主要为疏密切割型。体长与鳞长之间的直线相关L =2 .0 85 4+2 .36 2 0R和幂函数相关L =2 .85 12R0 .952 9中 ,以幂函数相关性密切 ;体重与体长呈指数函数相关W =2 .4 984× 10 - 2 L2 .9936 。 4龄以前生长较快 ,生长指标高 ,体长指标高 ,体长和体重的相对增长率大 ,其生长规律可用VonBertalanffy方程表达 :Lt=[1-e- 0 .132 5(t+ 0 .2 0 95) ],Wt=132 76 .4 0 [1-e- 0 .132 4 (t+ 0 .2 0 95) ]3。体重生长曲线的拐点位于t =8.0 9龄、W8.0 9=3933.6 1g ,即Wt=0 .2 96W∞ 处。倒刺雌性一般在 5龄性成熟 ,雄鱼 3～ 4龄时性成熟。建议江河捕捞对象应为 5 + 龄以上的个体。