New names for homonyms in the genus Dactylogyrus Diesing, 1850 (Monogenea, Dactylogyridae)

The following new replacement names for homonyms in the genus Dactylogyrus Diesing are proposed: Dactylogyrus acrossocheili nom. nov. for D. forcipatus Wu & Wang, 1983; D. birgii nom. nov. for D. simplex Birgi & Lambert, 1987; D. cheni nom. nov. for D. orientalis Hu & Chen, 1979; D. hui nom. nov. for D. xenocypris Hu & Chen, 1979; D. limae nom. nov. for D. hamatus Chinabut & Lim, 1994; D. mikailovi nom. nov. for D. gracilis Mikailov, 1974; D. pakistanensis nom. nov. for D. mrigali Rizvi, 1978; D. papernai nom. nov. for D. magnum Paperna, 1973; D. saurogobii nom. nov. for D. falcatus Wu, Wang & Song, 1983; and D. semifasciolatae nom. nov. for D. lineatus Luo & Lang, 1982.     

Age,growth and life history of Culaea inconstans (Pisces: Gasterostidae) in Delta Marsh Lake Manitoba

Culaea inconstans in delta Area, Lake Manitoba matures in the second summer of life, when between 29 and 65 mm in total length and one year of age. Spawning starts at the end of May after migration into the creeks and channels in the marsh. By June 11–12 the yearlings are under 20 mm in total length. The greatest part of growth is completed in the first summer of life. The asymptotic or average maximum length, L was 89.06 mm. Aging of fish was done by reading otoliths and plotting length frequency histograms. Fish set the first ring, a false check, in otoliths within the first month of life and the annual ring is set by the adults on June 1 of the second summer of life. Culaea inconstans was generally found to be an annual fish which died after spawning in the second summer of life. A high positive correlation coefficient was found for body-otolith relationship. The length-weight regression lines were significantly different from one another and from zero, the F-value being significant at 1% level. The condition factor was found to be variable.     

New and known species of Dactylogyrus Diesing, 1850 (Monogenea,Dactylogyridae) from Iranian freshwater cyprinid fishes

Three new Dactylogyrus species, D. rectotrabus n. sp. and D. acinacus n. sp. from Garra rufa plus D. carassobarbi n. sp. from Carassobarbus luteus are described from River Dez (Persian Gulf Basin) of Iran. Three known species, D. haplogonus from Rutilus frisii kutum, D. chalcalburni from Alburnus alburnus and Alburnoides bipunctatus, and D. pavlovskyi from Barbus sharpeyi are recorded from the Rivers Sefid (Caspian Basin), Zayandeh (Central Iran) and Dez (Tigris-Euphrates Basin), respectively. Comments on the monogenean fauna of Iranian freshwater fishes are presented.     

澜沧江鳘条寄生指环虫属两新种记述

本文记述了云南澜沧江水系景洪流域段(100°47'43″E,22°0'28″N)鳘条Hemiculter leucisculus(Basilewsky,1855)鳃丝上寄生指环虫属Dactylogyrus 2新种,以采集地命名为版纳指环虫Dactylogyrus bannaensis sp.nov.和景洪指环虫D.jinghongensis sp.nov.。版纳指环虫和景洪指环虫均为双联结片虫,基于后吸器,尤其是中央大钩、边缘小钩和交接器的形态学特征,鉴定为指环虫属科学上2新种。版纳指环虫交接器的形态有别于记录种船茎指环虫D.nilkolskyi Gussev,1955,版纳指环虫的交接管呈长带状,延伸至虫体左侧边缘阴道口处,末端微弯;感染率100%(40/40)。寄生于同一宿主的景洪指环虫,其交接器的形态有别于记录种红鲌指环虫D.erythroculteris和锥花指环虫D.pannosus,景洪指环虫的交接器呈彩虹状,交接管的一端基部膨大成漏斗状,另一端折叠;支持器"V"形,且中间包绕交接管;感染率100%(40/40)。     

Three new species of Dactylogyrus Diesing, 1850 (Monogenea: Dactylogyridae) from the gills of the bala sharkminnow Balantiocheilos melanopterus (Cyprinidae) from Thailand

Three new species of Dactylogyrus are described from the gills of the cyprinid fish Balantiocheilos melanopterus (Bleeker) imported from Thailand via the aquarium trade. They are D. coartatus n. sp., D. macrocolpius n. sp. and D. melanopteri n. sp. The double-bar species, D. coartatus n. sp. and D. melanopteri n. sp., are characterised by hooks that are markedly large in relation to the size of the anchors. Clip-like anchors with a sharply recurved, long point are a unique feature of D. coartatus n. sp. The single-bar species, D. macrocolpius n. sp., is characterised by having a copulatory organ composed of a spiral copulum and a medial accessory piece with thorns.     

Molecular phylogeny of species of Ligophorus (Monogenea: Dactylogyridae) and their affinities within the Dactylogyridae

The taxonomic framework of Ligophorus, monogenean specialists of the gills of grey mullets (Mugilidae), is evaluated and its interspecific relationships are assessed for the first time using molecular data. The position of Ligophorus within the paraphyletic Ancyrocephalinae is re-assessed based on newly sequenced species. Furthermore, the relationship between morphometric and genetic interspecific similarities is evaluated. Partial 28S and complete ITS1 rDNA sequences from representatives of 14 of the 16 nominal species of Ligophorus from the Mediterranean, Black and Azov Seas were analysed together with published sequences of members of the Dactylogyridae. The phylogenetic analyses of the Dactylogyridae (i) confirmed the position of Ligophorus within the marine Ancyrocephalinae; (ii) revealed a sister relationship between Ergenstrema and Ligophorus, whose species are all exclusive parasites of grey mullets; and (iii) substantiated the affinities of Ergenstrema with the marine Ancyrocephalinae. The phylogenetic analysis restricted to Ligophorus confirmed the distinct status of the included species. The ITS1 region provided the highest divergence between species and phylograms with the strongest branch support. Both the 28S and ITS1 phylograms revealed two main clades. One included species from hosts with Mediterranean and NE Atlantic distribution and another was formed by species parasitising several Liza spp., including Lz. haematocheilus from the Northwestern Pacific, and Mugil cephalus, which suggests an origin outside the Mediterranean for the latter clade. The phylogenetic evidence presented herein indicated that a combination of host-switching and lineage duplication events accounted for the diversification of this genus in the Mediterranean basin. The agreement between molecular and morphological interspecific similarities observed in Ligophorus supports the validity of morphometric characters used for species identification.     

New and known species of Dactylogyrus Diesing, 1850 (Monogenea,Dactylogyridae) from cyprinid fishes of the River Tigris,Iraq

Four new Dactylogyrus species are described and two redescribed from cyprinids of the River Tigris, Iraq. These are as follows: Dactylogyrus barbioides n. sp. from Barbus grypus; D. orbus n. sp. from Barbus lacerta; D. barbuli n. sp. from Barbus barbulus; D. macrostomi n. sp. from Cyprinion macrostomi; D. pavlovskyi Bychowsky, 1949 from Barbus grypus and Barbus sharpeyi; and D. inutilis Bychowsky, 1949 from Barbus xanthopterus. A phylogenetic and zoogeographical analysis is presented.     

澜沧江奇额墨头鱼寄生指环虫属单殖吸虫一新种记述

记述了澜沧江云南省西双版纳景洪流域段(22°00.288'N,100°47.430'E)奇额墨头鱼Garra mirofrontis寄生指环虫属Dactylogyrus单殖吸虫一新种:澜沧江指环虫Dactylogyrus lancangjiangensis sp.nov.。宿主鱼类的自然感染率为68%(19/28)。吸虫平均大小为317μm×101μm。后吸器由1对中央大钩、7对边缘小钩、联结片和副联结片组成;联结片呈一字形,中部狭窄,两端较宽;副联结片呈月牙形;交接器包括交接管和支持器,交接管基部膨大呈球形,后部缢缩形成细管,并盘曲成3~5圈螺旋;支持器呈复杂棒状,交接管端部从中穿过。本种在后吸器和雄性交接器上与指环虫属已记录种存在明显差异,同时鉴于单殖吸虫具有较强的宿主特异性,认为该种是科学上一未记录种。模式标本保存于云南师范大学生命科学学院。     

小鞘指环虫种群的聚集性研究

本文中建立了一个衡量聚集性的指标－聚集度Ａ,并用该指标结合方差／均数和负二项分布的参数ｋ值分析了小鞘指环虫（Ｄａｃｔｙｌｏｇｙｒｕｓｖａｇｉｎｕｌａｔｕｓ）种群在其宿主鲢（Ｈｙｐｏｐｈｔｈａｌｍｉｃｈｔｈｙｓｍｏｌｉｔｒｉｘ）种群中分布的聚集程度与感染率和丰度的关系。结果表明该虫种群的聚集程度随感染率及丰度的上升而呈现下降的特点,作为衡量聚集性的指标,聚集度要优于ｋ值,而后者又优于方差与均数之比,     

Watershed characteristics shape the landscape genetics of brook stickleback (Culaea inconstans) in shallow prairie lakes

Investigating the consequences of landscape features on population genetic patterns is increasingly important to elucidate the ecological factors governing connectivity between populations and predicting the evolutionary consequences of landscapes. Small prairie lakes in Alberta, Canada, and the brook stickleback (Culaea inconstans) that inhabit them, provide a unique aquatic system whereby populations are highly isolated from one another. These heterogeneous and extreme environments are prone to winterkills, an event whereby most of the fish die and frequent bottlenecks occur. In this study, we characterized the genetic population structure of brook stickleback among several lakes, finding that the species is hierarchically influenced by within‐lake characteristics in small‐scale watersheds. Landscape genetic analyses of the role of spatial features found support for basin characteristics associated with genetic diversity and bottlenecks in 20% of the sampled lakes. These results suggest that brook stickleback population genetic patterns may be driven, at least in part, by ecological processes that accelerate genetic drift and landscape patterns associated with reduced dispersal. Collectively, these results reinforce the potential importance of connectivity in the maintenance of genetic diversity, especially in fragmented landscapes.     

Diversifying and correlational selection on behavior toward conspecific and heterospecific competitors in brook stickleback (Culaea inconstans)

Behaviors toward heterospecifics and conspecifics may be correlated because of shared mechanisms of expression in both social contexts (nonadaptive covariation) or because correlational selection favors adaptive covariation. We evaluated these hypotheses by comparing behavior toward conspecifics and heterospecifics in brook stickleback (Culaea inconstans) from three populations sympatric with and three allopatric from a competitor, the ninespine stickleback (Pungitius pungitius). Behavioral traits were classified into three multivariate components: overt aggression, sociability, and activity. The correlation of behavior between social contexts for both overt aggression and activity varied among populations in a way unrelated to sympatry with ninespine stickleback, while mean aggression was reduced in sympatry. Correlations in allopatric populations suggest that overt aggression and activity may genetically covary between social contexts for nonadaptive reasons. Sociability was rarely correlated in allopatry but was consistently correlated in sympatry despite reduced mean sociability, suggesting that correlational selection may favor a sociability syndrome in brook stickleback when they coexist with ninespine stickleback. Thus, interspecific competition may impose diversifying selection on behavior among populations, although the causes of correlated behavior toward conspecifics and heterospecifics and whether it can evolve in one social context independent of the other may depend on the type of behavior.     

Isolation and characterization of microsatellite markers from the Hypoptychus dybowskii (Pisces,Gasterosteiformes)

Hypoptychus dybowskii (Gasterosteiformes) exhibits allopaternal care frequently caused by various types of male reproductive tactics (sneaking, egg desertion and taking over). In order to understand this interesting reproductive system, we isolated microsatellites loci from H. dybowskii. Five microsatellites showed 2–10 alleles and expected heterozygosities ranged from 0.15 to 0.84. These were not significant deviations from Hardy–Weinberg expectations. These results suggest that these novel polymorphic loci should be useful for parentage analysis of H. dybowskii.