A new species of Hysterothylacium (Nematoda: Anisakidae) parasite of Ariopsis guatemalensis (Osteichthyes: Ariidae) from Tres Palos lagoon, Mexico

Hysterothylacium perezi n. sp. is described from the intestine of the "cuatete" Ariopsis guatemalensis Günther, 1864 (Osteichthyes: Ariidae), in Tres Palos, a coastal lagoon located in the Mexican Pacific basin. The new species differs from all other species of Hysterothylacium Ward and Magath, 1917, in possessing a spinous postcloacal pad. In addition, H. perezi is readily distinguished from the 21 species described in fishes from America and Hawaii by having the greatest number of caudal papillae (47 to 51 pairs + 1 single, precloacal papillae). This species is the third described from hosts inhabiting estuarine environments in America and the fourth reported in Mexico.     

Morphology and taxonomic status of two little-known nematode species parasitizing North American fishes

Examination of some freshwater and brackishwater (estuarine) fishes in South Carolina in October 2009 yielded, in addition to other parasites, 2 little-known nematode species identified as Dichelyne fastigatus Chandler, 1935 (Cucullanidae), from the red drum, Sciaenops ocellatus (Linnaeus), from an estuary, and Rhabdochona ovifilamenta Weller, 1938 (Rhabdochonidae), from the shorthead redhorse, Moxostoma macrolepidotum (Lesueur), from Lake Moultrie. Light and scanning electron microscopy (the latter used for the first time for these species) made it possible to describe several important, but previously unreported, taxonomic features in D. fastigatus, such as the location of the excretory pore and deirids, the shape of deirids and a gubernaculum, the shape and size of eggs, the presence of precloacal ventral oblique muscle bands, and 11 pairs of caudal papillae and a pair of phasmids. It distinctly differs from the most similar Dichelyne cotylophora (Ward and Magath, 1917), a parasite of North American freshwater percids, in the number and arrangement of postanal papillae and by a markedly elevated cloacal region. Records of Dichelyne lintoni Barreto, 1922, from S. ocellatus probably concern D. fastigatus. Examination of R. ovifilamenta revealed a high degree of morphologic and biometric variability in this species. Based on our analysis, Rhabdochona laurentiana Lyster, 1940 , Rhabdochona milleri Choquette, 1951, and Rhabdochona catostomi Kayton, Kritsky, and Tobias, 1979, are synonymized with R. ovifilamenta Weller, 1938, typically a parasite of North American catostomids.     

Observations on the morphology of Truttaedacnitis clitellarius and T. lebedevi (Nematoda: Cucullanidae) from acipenserids and synonymy of the two species

Truttaedacnitis clitellarius (Ward & Magath, 1917) (Nematoda: Cucullanidae) is redescribed from the lake sturgeon Acipenser fulvescens from North America and compared with T. lebedevi (Skrjabina, 1966) from the Siberian sturgeon A. baeri. Studies on the morphology and morphometrics of the two species reveal considerable overlap with unique shared characters, such as the previously unreported position of the excretory pore at the level of the pseudobuccal capsule and arrangement of caudal papillae. This position of the excretory pore is anteriormost among all cucullanids. Although there is a trend towards smaller size of body and spicules in T. lebedevi, this reflects a long period of geographical separation and likely accounts for the minor morphological variations noted. Consequently, the two species are synonymised. The presence of one species of Truttaedacnitis, T. clitellarius, specific to freshwater acipenserids in North America and Siberia, suggests an ancient origin and slow rate of evolution for this cucullanid.     

假杆咽属线虫一新种及该属分类的讨论(旋尾目:杆咽科)

本文报道了在四川省马边县采集的旋尾类线虫一新种,定名为马边假杆咽线虫,新种Pseudorhabdochona mabianensis sp.nov.寄生于西昌华吸鳅Sinogastromyzon sichangensis Chang和齐口裂腹鱼Schizothorax prenanti(Tchang)的肠道中。该寄生虫的发现证明假杆咽属Pseudorhabdochona Liu etWu,1941不应该合并到杆咽属Anabdochona Rajlliet,(1916).       

Spinitectus acipenseri n. sp. (Nematoda: Cystidicolidae) from the lake sturgeonAcipenser fulvescens (Rafinesque) in Canada

Spinitectus acipenseri is described as a new species from the muscular stomach of the lake sturgeonAcipenser fulvescens from Manitoba and Saskatchewan. This new species closely resemblesS. gracilis Ward & Magath, 1917, but the major differences are the arrangement and larger size of spines (circlets and semicirclets of spines reaching to the anus in females ofS. acipenseri). Other differences include total body dimensions of adults (length and width relationships) and a 1:4–1:5 ratio of oesophagus to body length.     

Helminth and arthropod parasites of fishes in the mountain national parks of Canada

Sixteen parasite species including one monogenean, two digeneans, five cestodes, six nematodes. one acanthocephalan, and one copepod were collected from 257 fish of 13 species examined from 32 lake and nine stream sites in the mountain National Parks of British Columbia and Alberta. The following parasites are reported from Alberta for the first time: Bunodera luciopercae (Müller, 1776), Eubothrium rugosum Batsch 1786, Proteocephalus parallacticus MacLulich, 1943, Rhabdochona cascadilla Wigdor, 1918, Rhabdochona milleri Choquette, 1951, Contracaecum brachyurum (Ward & Magath, 1917), Bulbodacnitis truttae (Fabricius, 1794), Neochinorhynchus rutili (Mueller, 1780), and Ergasilus nerkae Roberts 1963. Tetraonchus variabilis Mizelle & Webb, 1953 and Rhabdochona milleri Choquette, 1951 are reported from British Columbia for the first time.     

Effect of starvation on morphometric changes in Rhynchocypris oxycephalus (Sauvage and Dabry)

A 75-day study was conducted to determine the effect of starvation on classical and truss parameters in Rhynchocypris oxycephalus (Sauvage and Dabry) . Truss dimensions of almost the entire head and trunk region as well as the abdomen were increased significantly through feeding or starvation (P   < 0.05). Truss dimensions of the caudal region generally decreased through feeding or starvation, particularly those dimensions at the hind part of the trunk. There were some significant decreases in classical dimensions of the head region during feeding, in relation to body depth characteristics in the trunk and caudal region during starvation, whereas there was only one decreasing classical dimension in the caudal region during feeding. The results of this study indicate that application of the truss network as a character set enforces classical coverage across the body form, discrimination among experimental groups thus being enhanced. Considering that the dimension of the lower part of the head and some truss and classical dimensions were least affected by feeding and starvation, these dimensions may then be useful as a taxonomical indicator to discriminate the species of Rhynchocypris sp. The value of trunk region dimensions with a large component of body depth in R. oxycephalus is most likely to be compromised by variability related to differences in feeding regimes of fish in different habitats.     

黄山九龙峰保护区尖头的年龄、生长和繁殖

于2011年5月至2012年4月逐月采集标本, 对黄山九龙峰保护区尖头 (Phoxinus oxycephalus)的年龄、生长和繁殖等生活史特征进行了研究. 尖头 雌、雄鱼性比为0.77:1, 与1:1差异显著. 根据体长频率分布来确定年龄组成,结果显示雌鱼和雄鱼的最大寿命分别为3龄和2龄, 均以1龄和2龄为优势年龄组. 1龄时的体长生长速度最大, 至2龄或3龄逐渐变缓. 雌、雄鱼的初次性成熟年龄均为2龄, 对应体长分别为93.0 mm和76.9 mm. 尖头 繁殖时间为4-7月; 绝对繁殖力较低(174-2151卵粒), 且在2、3年龄组间显著差异, 但相对繁殖力无显著的年龄组间差异. 尖头 的上述生活史特征, 可能体现了对局域环境条件(如营养贫乏、环境动荡及水文周期等)的生态适应性. 尖头 在我国东南部的高海拔地区呈零星分布, 种群数量小, 加之繁殖投入低下, 因此该物种在面临人类干扰和环境变化时极易濒危和灭绝.       

A review of flying fishes of the subgenus Hirundichthys (Genus Hirundichthys, Exocoetidae). Part 2. Nerito-oceanic species: H. oxycephalus, H. affinis

The second part of the review of the subgenus Hirundichthys s.str. dealt with two nerito-oceanic species of the subgenus which have weakly pronounced “mirror” on the pectoral fins: H. oxycephalus and H. affinis. The validity of H. coromandelensis (Hornell, 1923) as a subspecies of H. oxycephalus is restored. A comparison of local populations showed that H. oxycephalus is a polytypic species and forms three subspecies: nominative H. oxycephalus oxycephalus from the Western Pacific and Eastern Indian Ocean, H. oxycephalus coromandelensis from the Arabian Sea, Bay of Bengal and adjoining waters of the Indian Ocean, and known by the only specimen from the waters of New Guinea H. oxycephalus frereensis ssp.n. Populations of H. affinis from the Western and Eastern Atlantic differ in the color of pectoral fins. Maps showing the geographical distribution of species and subspecies in the World Ocean are drawn up. A key for identification of species and subspecies belonging to the subgenus is proposed.     

New data on the morphology of Philonema oncorhynchi Kuitunen-Ekbaum, 1933 (Nematoda: Dracunculoidea) from the abdominal cavity of Pacific salmon (Oncorhynchus spp.)

The dracunculoid nematode Philonema oncorhynchi Kuitunen-Ekbaum, 1933 is redescribed from specimens collected from three species of anadromous Pacific salmon, i.e. Oncorhynchus keta (Walbaum), O. kisutch (Walbaum) and O. nerka (Walbaum), from Japan, North Pacific Ocean and eastern Russia (Kamchatka), respectively. Scanning electron microscopy revealed the presence of hitherto undescribed cuticular ornamentations on the male caudal end and made it possible to establish the numbers, distribution and shape of cephalic and caudal papillae in the male, which are hardly visible under a light microscope; two horn-like protrusions and a median pre-anal papilla situated on the anterior cloacal lip were not previously described in this species. The necessity of detailed morphological studies on Philonema spp. parasitic in salmonids for the clarification of their taxonomy is stressed.     

Biodiversity and Biogeography of Chthamalid Barnacles from the North-Eastern Pacific (Crustacea Cirripedia)

The biogeography and ecology of the species of Chthamalus present on the west coast of America are described, using data from 51 localities from Alaska to Panama, together with their zonation on the shore with respect to that of other barnacles. The species present were C. dalli, Pilsbry 1916, C. fissus, Darwin, 1854, C. anisopoma Pilsbry 1916 and four species in the C. panamensis complex. The latter are C. panamensis Pilsbry, 1916, C. hedgecocki, Pitombo & Burton, 2007, C. alani nom. nov. (formerly C. southwardorum Pitombo & Burton, 2007) and C. newmani sp. nov.). These four species were initially separated by enzyme electrophoresis. They could only be partially separated by DNA bar coding but may be separated using morphological characters.     

A new species of Ochridacyclops (Kiefer, 1937) (Copepoda, Cyclopoida) from Japan

A new species of cyclopoid copepod, Ochridacyclops nipponensis is described from Japan. This is the third species of the genus. The type material was collected from small streams in the mountainous regions in Shikoku. The new species can easily be distinguished from other members of genus by its 12-segmented antennule, by the proportional length of genital double-somite relative to the length of 3 free abdominal somites, and by the shape of caudal rami. The male is unknown.     

赤水河外来鱼类尖头(鱥)和董氏须鳅的引种溯源及生态适应性分析

历史上,赤水河流域干流及支流的鱼类物种组成中未曾出现过尖头(鱥)(Rhynchocypris oxycephalus)和董氏须鳅(Barbatula toni).但是,近年来在赤水河支流白沙河的鱼类资源调查中发现了这两个物种的分布,其来源及未来的生存可能性受到关注.本研究比较了尖头(鱥)赤水河野外种群与养殖种群形态上的...     

Two new species of Cephalobellus Cobb, 1920 (Thelastomatidae: Nematoda) from coleopteran larvae from India

Summary Two new species of Cephalobellus, C. annulobellus and C. spicatus, collected from unidentified coleopteran larvae in Aligarh, India, are described and figured. Both species have characteristic closely set annules in the cervical region of their females and five pairs of caudal papillae and lateral alae in the males. C. annulobellus possesses a labial disc, has a smaller body and different shape and arrangement of caudal papillae than in C. spicatus. A key to the species of Cephalobellus is given. ac]19830610     

Sexual pattern ofNeocirrhites armatus (Cirrhitidae) with notes on other hawkish species

Synopsis We examined the gonads of eight species in five genera of hawkfishes. Histological preparations of ovaries and testes produced evidence for protogynous hermaphroditism inNeocirrhites armatus and suggested that hermaphroditism may also be expressed inCirrhitichthys oxycephalus, C. aprinus andC. falco, and possibly also by other species. Sexual patterns in hawkfishes are discussed in relation to environmental and ecological factors which influence mobility and length of spawning season.     

Glaciella,a new genus of freshwater Canthocamptidae (Copepoda,Harpacticoida) from a glacier in Nepal,Himalayas

A new genus and new species of Canthocamptidae: Glaciella yalensis (Copepoda: Harpacticoida) from the surface of Yale Glacier, Nepal is described. This new species was collected from cryconite-pit on the surface of the glacier and is closely related to genus Maraenobiotus, but easily distinguishable from its species in the following: 1) segments and setae on endopodites of legs 2–4 in the male differing shape, 2) exopodites of male legs 3–4 with modified setae, 3) caudal seta in female absent. Body color of this copepod is red in live specimens.Contributions No. 86 Itako Hydrobiological Station, Ibaraki University.     

New species of myxosporidans from fishes in the Lake Khanka basin

Two new myxosporidian species found in fishes from the Komissarovka River (Khanka Lake basin) are described: Myxobolus chankaensis sp. n. from Nemachilus barbatulatus toni and M. oxycephali sp. n. from Phoxinus lagowskii oxycephalus.     

温度驯化对尖头鳉热耐受特征的影响

为了研究不同驯化温度对尖头鰂(Rhynchocypris oxycephalus)热耐受特征的影响, 本研究设置4组水温(14℃、19℃、24℃和29℃), 对尖头鰂驯化两周, 采用临界温度法观察尖头鰂的耐受温度。结果显示: 尖头鰂的热耐受性受到温度驯化的影响, 表现为高温驯化可以升高最大临界温度(CT_max), 4个驯化组的平均CT_max分别为32.29℃、33.23℃、33.40℃和35.71℃; 低温驯化可以降低最小临界温度(CT_min), 平均CT_min分别为0.00、0.10℃、2.10℃和5.27℃; 在适中的温度(19℃)驯化条件下具有最高的温度耐受范围(33.13℃)。在高温条件下的温度驯化具有较高的驯化反应率, 最大值出现在24—29℃内(0.46); 低温驯化反应率最大值出现在29—24℃内, 为0.63。尖头鰂在本研究的驯化区间(14—29℃)内的热耐受区域面积为478.98℃2, 与温水性鱼类的温度耐受性相当, 说明尖头鰂具有较强的温度适应能力。     

Pseudophysaloptera enigmatica sp. nov. (Nematoda: Physalopteridae) from Dactylopsila trivirgata Gray, 1858 (Marsupialia: Petauridae) in Australia, with a review of the genus

The nematode Pseudophysaloptera enigmatica sp. nov. is described from the stomach of Dactylopsila trivirgata Gray, 1858, in Queensland, Australia. The new species is distinguished from congeners by its size and features present on the tail of the male. P. enigmatica sp. nov. is considerably larger than virtually all congeners, and can be differentiated by the presence of spicules and the shape and distribution of caudal papillae in the male tail. This is the first record of the genus in Australia and in marsupials. A review of the genus is provided.     

Character variation in separate body regions of Gerreidae (Osteichthyes: Teleostei) fishes inferred from geometric morphometrics

Body morphology is a valuable feature for distinguishing teleostean fishes. However, the utility of character variation in separate body regions has yet to be tested. The taxonomy of the Gerreidae family is controversial due to character overlapping among its fish species. This work aims to analyze and compare the body shape variation in three regions, cephalic, trunk, and caudal peduncle, using landmark data and geometric morphometric methods in 17 species and five genera of the family Gerreidae. The pattern of shape variation for the cephalic region consisted of well-defined character states exclusive of each species analyzed. Shape variation in the trunk and caudal peduncle regions does not distinguish all species in this study. This study showed that the dorsal cephalic profile is highly variable among the species, therefore, shape variation in this region is useful for distinguishing Gerreidae species. In contrast, some species within the same genus share similar shape states in the trunk and caudal peduncle regions, with the most shape variation in the dorsal profile and anal fin for the trunk and in the middle of the caudal peduncle.