A New Species Nemipterus (Nemipteridae) from Nha Trang Bay (Vietnam,South China Sea)

Journal of Ichthyology - From the coast of Vietnam, Nemipterus biendongensis sp. n. has been described, similar in body proportions to N. balinensoides, but differing from this species in a...     

Distribution and population dynamics of Porphyra (Bangiales, Rhodophyta) in the southern Western Cape, South Africa

Although Porphyra is commercially farmed in many countries, in South Africa only small harvests of wild populations for sale as nori have been carried out. The discovery that Porphyra improves growth of South African abalone (Haliotis midae) farmed inland-based tanks has led to increased pressure to harvest wild populations. This paper reports on a survey of the distribution and seasonality of Porphyra in the southern Western Cape. Porphyrawas present at all sites surveyed, and showed considerable temporal variation. A significant amount of the Porphyra present is in reserves and therefore protected from harvesting. Close rexamination of one site revealed seasonal populations of Porphyra that occupied different niches dependent on season. Recruitment peaked in spring and autumn, leading to dense summer and winter populations. Summer populations generally grew lower in the eulittoral than winter populations. No pattern in the mortality of larger thalli wasde tected, though sporeling mortality was high following recruitment peaks. Although it seems that most sites in the southern Western Cape are suitable for harvesting, the taxonomy of the genus in the region urgently needs revision if populations are to be appropriately managed. This revised version was published online in August 2006 with corrections to the Cover Date.     

大鹏湾反曲原甲藻种群动态机理模型辨识

建立了我国南海大鹏湾反曲原甲藻种群动态机理模型,在温度、盐度、溶解氧（ＤＯ）、可溶性无机磷（ＤＩＰ）、可溶性亚硝态氮、可溶性硝态氮和酸碱度（ＰＨ值）等７个因子的分析中,辨识出温度为反曲原甲藻的限制因子;种群数量变动中引入自回归平稳随机模拟,并建立３个站位６个层面的６个自回归与非线性回归联立模型,以动态递阶的方式对反曲原甲藻种群动态进行回代,研究模型对实测值的拟合结果,拟合率达８１．７％。     

A new species of the genus Nihonotrypaea Manning & Tamaki, 1998 (Crustacea,Decapoda, Axiidea,Callianassidae) from the South China Sea

A new species of the genus Nihonotrypaea Manning & Tamaki, 1998, Nihonotrypaea hainanensis sp. n., collected from the South China Sea, is described and illustrated. It is distinguishable from Nihonotrypaea harmandi (Bouvier, 1901), Nihonotrypaea japonica (Ortmann, 1891), Nihonotrypaea thermophila Lin, Komai & Chan, 2007 and Nihonotrypaea makarovi Martin, 2013 by having the elongated carpus of the male and female major cheliped. The new species is distinguishable from Nihonotrypaea petalura (Stimpson, 1860) by the proximolower margin of the carpus of the male major cheliped bearing several small denticles.     

Age and growth of an Iberian cyprinodont, Aphanius iberus (Cuv. & Val.), in its most northerly population

Age and growth of an Iberian cyprinodont, Aphanius iberus (Cuv. & Val.), in its most northerly population, La Rubina lagoon (Alt Empordà wetlands, NE Spain), was studied. The age groups for this Mediterranean population (O +, 1 + and 2 +) agree with those reported for the Atlantic population (R. Guadalquivir marshes), in the southern limit of the species distribution in the Iberian peninsula. Differences in age structure between these populations and the one previously studied in La Tancada lagoon (R. Ebro delta marshes) can be attributed to age estimation bias. Male A. iberus data appear to fit similarly to a Gompertz growth function and to a von Bertalanffy growth function, but L _x, was clearly underestimated. A Gompertz growth function was not a good fit for females, perhaps because female growth is clearly faster and less attenuated than male growth. The life history and growth pattern ofthis species is similar to that in other cyprinodontiform fishes, typified by a short longevity. The growth model of this species does not seem to fit types I and II of Sebens's classification, which are characteristic of fish.     

The population dynamics of Notothenia rossii from South Georgia (Antarctica)

Summary The population dynamics of nearshore juvenile Notothenia rossii were studied at South Georgia during 1978 and 1979. Mortality of the population was calculated from length-class abundance of fish sampled by trammel nets, and the population size estimated using a mark and recapture technique. Instantaneous natural mortality in the nearshore population was high (M=0.78) although other author's estimate for the mortality in the offshore population was only 0.35. Therefore it is likely that no single estimate of mortality will apply to fish of all ages. The population density of juvenile N. rossii was about 11 g m^-2 nearshore. The size of the offshore population was estimated by calculating survival from the nearshore age classes. The data suggest that the population around South Georgia has been reduced by overfishing to about one tenth of its previous unexploited level. Yield could have been increased by fishing less intensively, and the population maintained at or near its initial level if recruitment remained constant.     

The tolerance of grass carp Ctenopharyngodon idella (Val.) to seawatert†

Laboratory tests were conducted to determine the tolerance of 2+ grass carp to an oceanic water. It was found that at a temperature of 20.1°C±0.4°C the maximum survival times of the fish in concentrations of seawater equivalent to 17.5 and 10.5 g/1 sodium chloride were 5 h and approximately 24 days respectively. The importance of these results lies in the consideration of the possibility of grass carp migrating through brackish or seawater from one river system to another. Such a migration would seem to be impossible through seawater but may be possible through brackish water.     

Growth dynamics of myotomal muscle fibres in a carangid, Caranx malabaricus (Cuv. et Val.)

The growth pattern of myotomal red, pink and white muscle and its relation to somatic growth in Caranx malabaricus are described. The growth pattern of red muscle was by an increase in fibre number in early size classes (< 22 cm f.l.) and thereafter mainly by increase in fibre diameter and partly by increase in fibre number. The growth of pink muscle was mainly by an increase in fibre diameter, but in smaller fish an increase in fibre number was also evident. White muscle growth was mainly by an increase in fibre diameter and partly by increase in fibre numbers in fish < 22 cm f.l., but only by an increase in fibre diameter from 22 cm f.l. onwards. Caranx malabaricus is a slow-to-moderate growing species and its fibre growth pattern matches with such somatic growth.     

Egg population dynamics of naturally spawning dace,Leuciscus leuciscus (L.)

Synopsis Survival of dace eggs in a chalkstream was 8.6 to 21.8% from spawning to hatching. The proportion of dead eggs in samples rose from 4.9% at the end of spawning to 59% after 13 days. The combined number of dead eggs, live eggs and the empty shells of eggs after hatching also began a steady decline soon after the end of spawning. Egg drift was estimated to be 2.0% of the initial egg population. Laboratory studies and field population estimates indicated that macroinvertebrates were capable of eating large numbers of dead eggs but much smaller numbers of live ones. A large part of the fall in egg numbers was accounted for by egg decomposition. There was a close relationship between the percentage of surviving eggs and substrate composition with poor survival in areas of high silt and low gravel content.     

Food and feeding habits of the larvivorous fish Aplocheilus lineatus (Cuv. & Val.) in its natural habitat

Results are presented of a study of the food and feeding habits of Aplocheilus lineatus under natural conditions and the manner in which dietary preferences are influenced by the habitat/environment, seasons and stage of maturity of the fish is explained, based on data from montly random samples collected for a year. A qualitative assessment of the diet reveals that it is not confined to a varied range of aquatic fauna, but also encompasses allochthonous fauna. Quantitative and qualitative analyses of the diet indicate its feeding habit which does not alter with size or seasonal changes. The range of prey consumed does not differ radically, qualitatively, as a function of size, but quantitatively exhibits five levels of discrimination and differential exploitation related mainly to prey size. Seasonal fluctuations in feeding are more qualitative than quantitative and seem dependent on the occurrence of food organisms. The lack of correlation between breeding and feeding is linked to extent of the development of the gonad in the body cavity. In conclusion, the potential of the fish as an effective biological control agent of mosquito larvae is indicated by the fact that dipteran larvae are a preferred item of its diet in all size groups.     

Food habits of the mudskipper, Pseudapocryptes dentatus (Val.)

The food habits of the mudskipper, Pseudapocryptes dentatus (Val.) ranging from 43 to 205 mm in total length collected from the mudflats at Fao estuary, Iraq were studied. A combination of numerical, frequency occurrence and gravimetric methods was used to analyse the stomach contents, both qualitatively and quantitatively. The fish was found to be a strict herbivore and a frequent feeder. It fed solely on phytoplankton dominated by benthic forms. Diatoms were the most important food item in respect of both numerical and frequency occurrence methods comprising about 84% of the total number of phytoplankton organisms. The types of phytoplankton that contributed significantly to the diet were, in decreasing order of importance, Pleurosigma, Navicula, Nitzschia, Synedra, Closteriopsis and Oscillatoria . Larger fish had consumed lesser amount of food, and there was usually a gradual decrease in consumption with increase in size. The mudskipper consumed food ranging from 1·3 to 10·5% of its body weight.     

Variation of Freckled Goatfish <Emphasis Type="Italic">Upeneus tragula</Emphasis> (Mullidae): Color Morphs off Hon Thom (Gulf of Thailand,South China Sea)

Two color morphs of freckled goatfish Upeneus tragula with different Vietnamese names and mainly black and red body coloration of fresh dead exemplars are found off Hon Thóm (Thom Island), the largest island of An Thoi Archipelago located to the south of Phu Quoc Island, Gulf of Thailand, South China Sea. The presence of the morphs may be connected with the occurrence of two sympatric stocks or with color variation within a single stock. To test these hypotheses, red color content on the body (based on digital analysis of images) and gonadal condition is compared in both morphs. Body coloration does not depend on the sex of the fish. The black morph differs from the red morph in a smaller body size (12.7 vs. 16.4 cm FL on average), and it is represented by mainly immature individuals of both sexes (mean gonadosomatic index of the females 0.5 vs. 2.0%). It is proposed that the change of body coloration is associated with sexual maturation, and it occurs in the ontogeny within a single stock.     

南海生物多样性的保护

海洋对我们有很大的魅力,仅就生物多样性而言,我国是联合国《生物多样性公约》的最早缔约和制定保护生物多样性行动计划的国家之一,保护生物多样性是我国人民必须履行的共同义务,也是关系子孙后代生存的大事.1地理位置南海位于我国东南,面积约350 km2,平均深度为1,212 m,最大深度为5,377 m.它是一个长轴东北-西南向的边缘海,由西沙、中沙、东沙和南沙群岛构成,四大岛礁群散布其中,西南还有北部湾和泰国湾两大海湾.南海东临菲律宾群岛,北靠华南大陆,南接加里曼丹和苏门答腊,西接马来半岛和中南半岛.南海周边共有9个海峡,与东海、太平洋、苏禄海、爪哇海和印度洋相连通,地理位置非常重要,是欧、亚、非通道,在安全航运、经贸往来、环境保护、资源开发和军事战略等方面都具有非常重要的地位.     

Redescription of Flexophora ophidii Prost & Euzet, 1962 (Monogenea: Diclidophoridae) from Ophidion barbatum (Ophidiidae) off the Algerian coast,Mediterranean Sea

Systematic Parasitology - The diclidophorid Flexophora ophidii Prost &amp; Euzet, 1962, the type- and only species of the genus Flexophora Prost &amp; Euzet, 1962, has never been...