The Activity Rhythm of Blennius sanguinolentus Pallas*

Abstract. In the field, feeding activity of the algivorous Blennius sanguinolentus increased remarkably from morning to late afternoon. Swimming is evenly distributed; other behaviour does not fall into regular daily patterns. No association was found, save in extreme values, between the distribution of any activity and environmental factors measured simultaneously. We suggest that the feeding cycle is an adaptation to the metabolic properties of green algae, the staple diet of B. sanguinolentus. Activity distributions following predictable short-term fluctuations in food quality are expected to be found in other animals.     

福建南部沿岸水域尖头斜齿鲨的食性

对福建南部沿岩水域尖头斜齿鲨食性的分析表明：尖头斜齿鲨以硬骨鱼类，头路类，长尾类和口足类为主要食料，其营养级为３．４５，年平均饱满指数为９．４５‰，摄食率为７６％，其雌鱼在分娩期间仍有摄食，但强度降低，雌、雄个体食物组成无明显差异，幼鱼摄食强度大于成鱼。     

Feeding Habits of the Mesopelagic Fish Gonostoma gracile in the Northwestern North Pacific

The diet of Gonostoma gracile, a numerically abundant mesopelagic fish in the Subtropical Region and the Transition Domain of the northwestern North Pacific, was examined using 520 specimens collected during June–July 1988, June 1995 and November 1995. The prey included mainly copepods, ostracods, amphipods and euphausiids. Copepods and ostracods were the most abundant, comprising approximately 70% of the total diet. There was little evidence of an ontogenetic dietary shift; Pleuromamma copepods were the most abundant prey for all size classes of fish ranging from 19 to 116 mm in standard length. The size range of prey increased with growth, but all fish sizes examined fed mainly on 1–4 mm long prey. Luminescent copepods and ostracods were the most abundant prey, suggesting that G. gracile detects its prey visually. This revised version was published online in August 2006 with corrections to the Cover Date.     

Size-dependent, Spatial, and Temporal Variability of Juvenile Walleye Pollock (Theragra chalcogramma) Feeding at a Structural Front in the Southeast Bering Sea

Abstract. The waters surrounding the Pribilof Islands are an important nursery ground for juvenile walleye pollock (Theragra chalcogramma), an important forage fish in the pelagic food web of the productive Bering Sea shelf region. The diet of juvenile pollock was studied in two consecutive years along a transect line crossing from a well‐mixed coastal domain, through a frontal region to stratified water farther offshore. Variability in stomach fullness was high and evidence for increased feeding intensity in the front was weak. Prey diversity and prey size generally increased with increasing fish size, shifting from predominantly small copepods to larger, more evasive prey items such as euphausiids, crab megalopae and fish. The diet of the fish reflected changes in the relative abundance of copepods and euphausiids in the prey fields between years. Juvenile pollock showed increased feeding rates at dusk, and stomach fullness as well as prey condition were generally lowest just before sunrise; however, the proportion of euphausiids increased in the diet of pollock caught at night, suggesting that some food was also ingested during darkness. Juvenile pollock and their euphausiid prey both vertically migrated above the thermocline at night, although each had a different daytime depth.     

厦门近岸海域大型底栖动物摄食功能群及其与环境因子的关系

根据2013年5月和11月在厦门周边海域60个取样站获得的大型底栖动物数据,运用功能群方法分析该海域大型底栖动物功能群的时空格局及其与环境因子的关系。共鉴定大型底栖动物9门160科411种,其中肉食者152种,浮游生物食者102种,碎屑食者103种,杂食者48种和植食者6种,菲律宾蛤仔（Ruditapes philippinarum）和丝鳃稚齿虫（Prionospio malmgreni）分别是该海域春、秋季的主要优势种。总体而言,浮游生物食者和肉食者为该海域的主要优势功能群,但各区域的优势功能群存在一定差异,围头湾的主导功能群为肉食者和碎屑食者,大嶝海域以肉食者和浮游生物食者为主,而九龙江口和同安湾则以碎屑食者和浮游生物食者占优势。典范对应分析结果表明,水深和底温是影响该海域大型底栖动物功能群时空格局的主要因素,活性磷酸盐、底盐、有机质和叶绿素a等对其分布也有一定的影响。     

饵料、温度和个体规格对脉红螺摄食的影响

利用实验生态学方法,通过分析摄食喜好系数、单位体质量摄食量等参数,研究脉红螺(Rapana venosa)的摄食选择性,以及饵料种类、温度和个体规格对脉红螺摄食量的影响。结果表明,脉红螺(壳长100~120mm)具有明显的摄食选择性,喜食缢蛏(Sinonovacula constrzcta)、竹节蛏(Solen gouldi)和中国蛤蜊(Mactra chinensis),但不同饵料对其摄食量的影响不显著。随着温度的升高,不同规格脉红螺的摄食量变化趋势相似,即温度低于7℃时基本不摄食,温度高于16℃时开始大量摄食,22℃左右时达到摄食高峰。不同规格的脉红螺,随壳长的增加,单位体质量摄食量逐渐减小。不同壳长的脉红螺(38~108 mm),随壳长的增加,最低摄食温度先降低(壳长50~70 mm脉红螺最低摄食温度最低)后升高。本研究为脉红螺的人工养殖提供了理论依据,同时为脉红螺的生态影响评估提供参考。     

Distribution,habitat and movement of juvenile smooth hammerhead sharks (Sphyrna zygaena) in northern New Zealand

The smooth hammerhead shark, Sphyrna zygaena, occurs in warm temperate waters around the northern North Island of New Zealand. Commercial fishing records and research trawl survey data were used to determine their distribution. Highest catch rates were recorded in relatively sheltered bays and coastlines along the northeast coast of North Island. Neonate and juvenile sharks use shallow coastal waters and large harbours and estuaries as nursery areas up to an age of two years and total length of 150?cm. Five sharks were electronically tagged but two apparently died and three (137–160?cm total length) returned useful data. Two tagged sharks remained in or near the Bay of Islands for 6–55 days after tagging, moving extensively through the bay. A third shark moved about 155?km southeast in 250 days. That shark spent 70 days mostly shallower than 10?m (94% of time) with occasional dives to 40?m. Thereafter, it oscillated between the surface and depths of 60?80?m, with most time (55%) being spent at 40?60?m. Maximum recorded depth was 144?m.