Genetic relationships of four Taiwan mullets (Pisces: Perciformes: Mugilidae)

Electrophoretic data for 19 presumptive gene loci separated Mugil cephalus from Liza spp. with Nei's genetic distance of 0.863, and from Valamugil formosae with 0.703, and from both Liza and Valamugil with 0.783. Within the genus Liza , Nei's genetic distance was only 0.237 between L. affinis and L. macrolepis.     

Fish communities in temporarily open/closed estuaries from the warm- and cool-temperate regions of South Africa: A review

The majority of estuaries along the coastline of southern Africa are termed temporarily open/closed estuaries (TOCEs) and are closed off from the sea for varying periods by a sandbar which forms at the mouth. It is therefore important to understand the processes occurring within TOCEs and their importance to fishes in order to make sound management recommendations. Estuaries along the coast of South Africa and their associated fish assemblages are biogeographically distinct and occur in either a subtropical, warm-temperate or cool-temperate zone. There are 125 TOCEs found within the cool-temperate and warm-temperate zones. Most fish species found in TOCEs are the juveniles of marine taxa that breed at sea. Permanently open estuaries generally have a higher diversity of species than TOCEs, but TOCEs still provide important nursery areas for many marine species and numerically often have a higher proportion of estuarine resident species. Important taxa in terms of abundance and biomass in warm-temperate TOCEs include the sparids Rhabdosargus holubi and Lithognathus lithognathus, several mugilid species, estuarine residents (particularly Gilchristella aestuaria and Atherina breviceps) and the freshwater cichlid Oreochromis mossambicus. The diversity of fishes in cool-temperate TOCEs is low when compared with warm-temperate systems and Liza richardsonii tends to dominate catches by number and mass in most systems. Several species recorded in TOCEs show clear longitudinal distribution trends. For example Atherina breviceps is generally more abundant in the lower reaches of estuaries. Mouth state, particularly the frequency, timing and duration of mouth opening plays a key role in determining species richness, composition, diversity and abundance in TOCEs. Mouth state is directly linked to freshwater input. Reduced river inflow leads to prolonged mouth closure and shorter open phases, which inhibits immigration and emigration of marine fish species between estuaries and the sea. Understanding of the effects of various processes occurring within these systems, particularly variation in freshwater input, on the biota of these important systems facilitates the development of informed management recommendations.     

Ecological relations in the evolution of acanthopterygian fishes in warm-temperate communities of the northeastern Pacific

Synopsis The species composition of acanthopterygian fishes in warm-temperate communities of the northeastern Pacific reflects the influence of ecological relations on teleostean evolution. The species are of either temperate or tropical derivation, with the temperate derivatives (e.g., scorpaeniforms, pleuronectiforms and zoarcoid perciforms) being mostly generalized carnivores, and the tropical derivatives (almost all of them perciforms) ranging from generalized carnivores to a diversity of specialized carnivores and herbivores. The tropical group dominates, with species of the labroid families Pomacentridae, Embiotocidae and Labridae being especially prominent, based mainly on specialized abilities to feed on sessile invertebrates and zooplankters. Other perciforms of tropical stock that do well here include kyphosids, which are herbivores. These trophic capabilities have been inherited from tropical ancestors and are poorly developed among the temperate derivatives. Despite their successes in warm-temperate habitats, few tropical derivatives have extended their distributions into the cold-temperate region; similarly, temperate derivatives have been to a large extent limited in spreading southward into the warm-temperate region. These limits to distribution cannot be attributed to problems with food resources, but are readily explained by effects of surface currents on early life-history stages in this coastal upwelling system.     

Fishery, seasonal abundance and mortality of grey mullets (Pisces: Mugilidae) in Negombo Lagoon, Sri Lanka

The seasonal abundance and instantaneous natural and fishing mortalities of six species of grey mullets, namely Liza subviridis, L. macrolepis, L. tade, Mugil cephalus, Valamugil buchanani and V. cunnesius were studied as a prelude for the management of their fishery in Negombo lagoon (7°10′N and 79°50′E). L. subviridis was the most abundant of the grey mullet species in the commercial catches and accounted for 37% of the total grey mullet catch. M. cephalus was the least abundant and constituted 6%. The annual catch of grey mullets was estimated to be around 23 000 kg (5.67 kg/ha); about 40 % of the total fish landings of the lagoon. The seasonal variation in the catch of different species of grey mullets appear to be related to their breeding seasons and spawning migrations. The highest value for instantaneous natural and fishing mortalities, which were 1.04 and 0.94 respectively were obtained for V. cunnesius. The lowest values for instantaneous natural and fishing mortalities which were 0.51 and 0.19 respectively were obtained for M. cephalus. The exploitation ratios calculated were less than 0.5 for all species other than L. tade which suggest that the grey mullet populations excluding L. tade in this lagoon may presently be underexploited.     

Food and feeding ecology of piscivorous fishes at Lake St Lucia, Zululand

The food and feeding ecology of piscivorous fish in Lake St Lucia was monitored for two years. Piscivorous fishes feed predominantly on the planktivorous Gilchristella aestuarius and Thryssa vitrirostris but a wide range of prey species was recorded. Numbers of the predominant piscivores, Argyrosomus hololepidotus and Elops machnata , in an area appear to be related to the densities of their major prey, T. vitrirostris and G. aestuarius . Large piscivorous fishes are restricted to the deeper portions of the lake, whereas small piscivores such as Johnius belengerii and Terapon jarbua feed predominantly on small fishes in the littoral zone. The highly significant correlation between the composition of prey fish species in the lake and prey fish species in the diet of piscivorous fishes, indicates that piscivores are feeding in a density dependent manner. However, factors such as habitat, fish size and swimming speed of prey species are shown to be important in prey selection. Juvenile fish of species such as Sarotherodon mossambicus, Liza macrolepis and Acanthopagrus berda remain in shallow marginal areas, thus avoiding large piscivorous fishes. However by frequenting shallow areas these species become vulnerable to bird predators, especially egrets and herons.     

Composition and seasonal fluctuations of intertidal fish assemblage in Kohr al-Zubair, Northwestern Arabian Gulf

A total of 2,851 fishes belonging to 34 species and weighing 177.15 kg were caught between July 1983 and June 1984 near Kohr al-Zubair in the northwestern Arabian Gulf, using four types of fixed gillnets with different mesh sizes. Four species (Thryssa hamiltoni, Liza macrolepis, T. mystax and Nematalosa nasus) formed 82.1% of all fish while 3 species (L. macrolepis, T. hamiltoni, Pomadasys argenteus) comprised 50.3 % of the total wet weight. The abundance of species was highest during autumn and spring, clearly reflecting the high values for the diverse indices during these periods and indicating the differing biological fish utilization of Kohr al-Zubair. The high positive correlation of temperature to number of species played an important role in this abiotic factor of fish migration to and from Kohr al-Zubair. Quantitative clustering of common fish species based on individual samples showed six distinctive groups. Group I included four resident species, while groups II-VI comprised mainly seasonal species that entered the Kohr area during either warm or cold seasons.     

中国海毛颚类物种多样性的研究

中国海已记录毛颚类有37种,可分为3个生态类群,即暖水性、暖温性和深水类群。种数是由北往南、由近岸向外海递增。中国海毛颚类可划分暖温带区系、热带- 暖温带混合区系和热带大洋区系。大多数种类广泛分布于印度洋、大西洋和太平洋等水域。     

云南蔷薇科植物的区系特征和地理分布

蔷薇科是云南种子植物区系中的第5大科,有41属456种,其属种分别占我国蔷薇科的74.5%和52.2%.云南蔷薇科植物的区系物征:1)云南蔷薇科属种十分丰富,分别占国产属的3/4和种的一半以上;而且该科植物中原始的、中间过渡的和进化的类群在云南均有分布.2)区系地理成份相当复杂,以包括北温带和东亚等分布类型为主的温带成分占优势.3)蔷薇科在云南的地理分布为5个区.该科植物在滇西、滇西北区种类最为丰富,占总种数的65.7%,其次是中部高原区、滇东南区及滇南和滇西南区较少,滇东北区最少.云南是蔷薇科植物的一个现代分布中心和分化中心之一.     

云南易门翠柏和黄彬的群落调查及保护

国家二级保护植物翠柏（Calocedrus macroleqis Kurz）和黄杉（Pseudotsugaa sinensis Dode）,仅在云南易门有较大面积的纯林分布,是很有保护价值的2个树种和相应的2个森林群落,现已成为全国唯一的翠柏和黄杉自然保护区。本文从群落特征、区系和种群分布格局的角度,首次较全面地分析了翠柏和黄杉极需保护的重要性。结果表明翠柏幼苗的耐阴性及黄杉幼苗的喜光性都是其分布范围受限制的主要原因之一;根据化石资料得出翠柏可能起源于滇中南;从分析群落中种子植物属的分布区类型得出翠柏的分布地生境比黄杉更趋于热带性。这些研究为翠柏及黄杉的就地保护和迁地保护提供理论依据。     

Phylogenetic Analysis of Mediterranean Mugilids by Allozymes and 16S mt-rRNA Genes Investigation: Are the Mediterranean Species of Liza Monophyletic?

The family Mugilidae (Pisces, Mugiliformes) includes species which are present in all tropical and temperate regions. Six species, Chelon labrosus, Mugil cephalus, Liza aurata, L. ramada, L. saliens, Oedalechilus labeo, are commonly found in the Mediterranean. These species have been widely studied through morphological, biochemical, and molecular markers. However, their phylogenetic relationships, and therefore the assumed monophyly of Liza species, still remain unclear: To further investigate this topic, gene-enzyme systems and sequences of the partial 16S rRNA mitochondrial gene were analyzed in Italian samples of all six Mediterranean species. The phylogenetic reconstructions indicated M. cephalus as being the most divergent species and the existence of a main cluster including all the Mediterranean species of Liza and C. labrosus. The parametric bootstrap approach adopted to test alternative phylogenetic hypotheses indicated that the Mediterranean species of Liza do not form a monophyletic group exclusive of Chelon.     

Long-term comparison of the fish community in a Costa Rican rocky shore marine reserve

Despite their role in supporting diverse marine fish communities, tropical rocky shores and reefs have attracted less research and fewer targeted conservation efforts compared to coral reefs. We studied fish community composition in Playa Blanca Marine Reserve (9 degrees 40' N - 84 degrees 40' W), a rocky shore site on the central Pacific coast of Costa Rica. We conducted visual surveys of fishes along six strip transects soon after the area was designated a marine reserve in 1995, then again in 2006 following an eleven-year period of complete protection. We recorded a total of 31 406 sightings of 72 species from 30 families. Pomacentrids (42.5%), labrids (16.6%) and haemulids (14.8%) dominated the community, accounting for > 70% of total fish abundance. In comparison to other sites in the region, the fish community was more similar to one reported from Bahia Honda, Panama (7 degrees 50' N - 81 degrees 35 W) than from the geographically more proximate Culebra Bay, Costa Rica (10 degrees 45' N - 85 degrees 43 W). Sixty-one species from 26 families were recorded in 1995; sixty-nine species from 28 families in 2006. Our results suggest that the Playa Blanca Marine Reserve is fulfilling its conservation role. Average fish abundance, species richness and Shannon's index of community diversity were greater in 2006 than 1995, and fish community composition varied significantly within each transect among years. Much of the change in community composition among years resulted from spatial and temporal variation in the abundance of a few dominant species, including Abudefduf troschelli, Thalassoma lucasanum, Chromis atrilobata, and Stegastes flavilatus/acapulcoensis. Of the 48 species/species groups recorded in both years, 37 (77%) were more abundant in 2006 than 1995, and several species recorded as uncommon or rare in 1995 were more frequent and abundant in 2006. Fish community composition and the abundance of some species changed in the reserve over time, but further study is needed to determine the role of small-scale marine reserves in the conservation of tropical marine biodiversity.     

Age validation and variation in growth,mortality and population structure of Liza argentea and Myxus elongatus (Mugilidae) in two temperate Australian estuaries

This study investigated variation in the rates of growth and mortality, and age and fork‐length (L_F) compositions of two exploited species of Mugilidae, Liza argentea and Myxus elongatus, in two south‐east Australian estuaries (Lake Macquarie and St Georges Basin). An ageing protocol was developed by counting opaque growth zones on sectioned otoliths which was validated by periodically examining the otoliths of captive‐reared young‐of‐the‐year fishes, and marginal increment analysis of wild fishes. The maximum recorded age was 17 years for L. argentea and 12 years for M. elongatus, which is greater than generally observed in other species of mugilids. Growth models of each species significantly differed between sexes and, except for male L. argentea, between estuaries. Fishes from Lake Macquarie generally had a greater mean L_F at age than those from St Georges Basin and females of both species generally attained a greater maximum L_F and age than males. Gillnet catches of L. argentea were of similar L_F and age compositions in both estuaries, whereas the age composition of catches of M. elongatus in Lake Macquarie contained a greater proportion of younger fish. Estimates of total, natural and fishing mortality were greater for M. elongatus than L. argentea across both estuaries, and estimates of total mortality were greatest for both species in Lake Macquarie. The data indicate that neither species has been overfished in these estuaries.     

The influence of turbidity on juvenile marine fishes in estuaries. Part 2. Laboratory studies,comparisons with field data and conclusions

The turbidity preferences of juveniles of 10 marine species common in estuaries of southeastern Africa were investigated in an experimental turbidity gradient. The tests allowed the elimination of all environmental factors except turbidity.Liza dumerilii (Steindachner), was found to be a clear-water species (< 10 NTU);L. macrolepis (Smith),Rhabdosargus sarba (Forsskal),Gerres filamentosus Cuvier, andValamugil buchanani (Bleeker), preferred “clear to partially turbid” water (< 50 NTU);Monodactylus argenteus (L.) preferred intermediate turbidities (10–80 NTU); and the remaining four,Rhabdosargus holubi (Steindachner),Acanthopagrus berda (Forsskal),Pomadasys commersonni (Lacépède) andTerapon jarbua (Forsskal), were indifferent to turbidity. Statistical analysis of laboratory and field data revealed significant correlations. The results of these are discussed in relation to fish distribution patterns, ecology, and the importance of turbidity to juvenile marine fishes in estuaries.     

The fish species composition and variation of catch from the small-scale gillnet fishery before, during and after the 1997-1998 ENSO event, central Mexican Pacific

In the tropical and subtropical coastal zone, were highly diverse fish communities occur, it is important to study the small scale fisheries exploiting these communities. For this study, 219 fishing days were carried out in Bahia de Navidad, Jalisco, Mexico. Four gillnets with different mesh sizes (76.2, 88.9, 101.6 and 114.3 mm) were used for the fishing operations, from April 1994 to March 1995 and from January 1998 to December 2000. A total of 26126 organisms weighting 11680 kg were caught. One hundred and eighty three species belonging to 57 families and 19 orders were identified. Ten species accumulated more than 60% of the total abundance and biomass, the remaining species (173) individually contributed with less than 2% of the total abundance and biomass. The most important species in the catch were Microlepidotus brevipinnis, Caranx caballus, Haemulon flaviguttatum, Scomberomorus sierra, C. caninus, C. sexfjasciatus, Lutjanus guttatus and L. argentiventris. The catch per unit of effort showed a large variation during the study, both in number and biomass. On average, 110 fishes and 48.5 kg fishing day(-1) were caught. The maximum values were recorded during January and October 1998 (250 fishes and 100 kg fishing day(-1)), and the minimum values were recorded during September and November 1994 (25 org. and 10 kg fishing day(-1)). The total abundance and biomass was lower during the 1994-95 period (F=6.16, 8.32, P<0.05). There were statistically significant differences among the annual catch from each gillnet. All the environmental changes caused by the ENSO event had ecological and economic effects that can be rated from moderate to severe.     

Biogeography and phylogeny of Dermoergasilus Ho & Do, 1982 (Copepoda: Ergasilidae), with descriptions of three new species

Three new species of Dermoergasilus are described from six species of grey mullet hosts. Dermoergasilus longiabdominalis n. sp. was found on Valamugil engeli (Bleeker) from the Philippines and Madagascar and on V. cunnesius (Valenciennes) from the Philippines and Mangalore, India. D. semiamplectens n. sp. occurred on Sicamugil hamiltoni (Day) from the Sittang River, Burma, on Liza subviridis (Valenciennes) and L. parsia (Hamilton Buchanan) from Calcutta, India, and on V. cunnesius (Valenciennes) from China. D. curtus n. sp. parasitised Rhinomugil squamipinnis (Swainson) from Alahabad, India. A key to the ten currently accepted species of Dermoergasilus is given. The biogeographical distribution of Dermoergasilus species is analysed and levels of host-specificity are surveyed within the genus. The phylogenetic relationships between the species of Dermoergasilus are also analysed.     

滇川干热河谷种子植物区系成分研究

论及滇川干热河谷种子植物区系成分由科级到种级的研究结果。用于统计分析的植物共1707个种,分属于752个属,165个科．科级区系成分中,除广布科外,明显为主,其次为暖温带科和热带科,热带科有27个科,远比干暖河谷区系中的热带科多。属区系成分中,热带属占明显多数,有523个属,占75．03％,温带属158个,占22．67％,有个中国特有属。种级区系成分中,有中国特有种622个,占37．42％,热带种791个,占47．59％,温带种249个,占14．88％。干热河谷的植物区系标志种很丰富,有437种,分三个等级,其中一级为本河谷特有种,有45种,二级199种,三级193种。热带科、属、种偏多说明本河谷历史上以热带区系为主和近代区系源于热带。干热河谷的特有区系成分和区系的标志种均较好地反映本河谷区系成分组合特征、演化的近代趋势、区系的多样性及其独特性。     

Fish entrapment in the seawater intake of a power plant at Karachi coast

Synopsis The study deals with the entrapment of fishes in the intake of Karachi Nuclear Power Plant. A total of 62 species of marine fishes belonging to 43 genera were observed entrapped in the seawater intake. Therapon puta, Liza waigiensis, Abudefduf septemfasciatus, and Lagoceptalus inermis were the most common. Mass mortalities of the juveniles of Sardinella sindensis were recorded in September and October of 1974, 1975, and 1977. Commercially important fishes such as sardines, mullets and anchovies, were entrapped in the intake of the power plant in considerable numbers at various times of the year. The majority of fishes removed from the screen washes of the power plants were killed by impingement.     

Fish larvae association in a Mexican Caribbean bay

Interannual ichthyoplankton variation, was analyzed in Bahía de la Ascensión, Mexico, during December of four consecutive years (1994-1997). A total of 32 families, 35 genera and 21 species of fish larvae were identified. The most abundant fish larvae were the Gobiidae followed by the Callionymidae, Clupeidae and Tetraodontidae. Larval diversity was low when compared with other periods ("dry" and "rainy"). Three spatial associations (internal, medium and external) were found in December 1994 and 1995. In 1996-1997, stations of the inner and outer parts of the bay were mixed. The dominant families characterized most of the faunal associations. Egg density was highest in the external zone of the bay, whereas larvae were most abundant in the inner area. Major factors affecting the fish larval assemblages during December (1994-1997) in Bahía de la Ascensión seem to be related to the nursery areas location and to the tropical fishes reproductive period.     

INFLUENCE OF FRESHWATER FLOW REGIME ON FISH ASSEMBLAGES IN THE GREAT FISH RIVER AND ESTUARY

Summary

Two and a half years of data were collected from the lower Great Fish River, head region and estuary to determine the fish species composition within these areas. Gilchristella aestuaria, Liza dumerilii, Rhabdosargus holubi and Pomadasys commersonnii were the four most abundant species captured, with riverine flow rate having an important effect on both species composition and numbers of fishes in the different regions. Most marine species displayed a strong inverse relationship between catch per unit effort and elevated freshwater inputs. Euryhaline marine species dominated the catches at all sampling sites during low flows but were less common during high flow periods when catadromous species were most abundant. Based on the available evidence it is suggested that for most marine species in the river this decline in abundance is related to low conductivity levels following floods rather than avoidance of elevated flows. The impact of elevated suspensoid concentrations and lowered dissolved oxygen concentrations on freshwater and estuarine fish populations during major river flooding is also discussed.     

Seasonal and interannual variation in fish assemblages of northern temperate rocky subtidal habitats

Fish assemblages on two inshore rocky subtidal sites on the west coast of Scotland, were studied using diver visual surveys on a monthly basis between September 1995 and December 1999. A total of 17 689 fishes and 26 species were recorded from the two sites, Saulmore Point (056°27'N; 005°24'W) near Oban and Davy's Rock (055°46'N; 004°53'W) on the Isle of Great Cumbrae. The gobiid Thorogobius eppiphiatus , dominated the Saulmore Point site; six fish species accounted for >93% of total abundance at that site. At Davy's Rock four species contributed at least 93% of total fish abundance, and the dominant species was the labrid Ctenolabrus rupestris . Total abundance of the dominant species displayed a clear seasonal trend, and this was significantly related to recorded daily average seawater temperature. A maximum abundance of 4.9 fishes m⁻² was recorded in November 1998 at Davy's Rock and 2.5 fishes m⁻² at Saulmore Point in October 1998. Multivariate analysis indicated a degree of variation in assemblage structure between winter and summer at both sites. A number of species showed some degree of interannual variation, in particular the gobiid Gobiusculus flavescens whose abundance increased by over 300 times over a 5 month period in 1998. Correlation analysis showed that variation in annual winter seawater temperature could act as an indicator of interannual variation in abundance of some of the dominant species utilizing rocky subtidal habitats.