Lahontan cutthroat trout ( Oncorhynchus clarki henshawi ) spawning and downstream migration of juveniles into Summit Lake, Nevada

The only remaining self-sustaining native population of lacustrine Lahontan cutthroat trout ( Oncorhynchus clarki henshawi ) not affected by nonnative salmonids is in Summit Lake, Humboldt County, Nevada. Annual spawning runs in 1993 and 1994 were monitored at a fish trap on Mahogany Creek, the only spawning tributary for Summit Lake. Number of spawners was similar in both years, with 1290 upstream migrants observed in 1993 and 1255 in 1994. In 1993, 137 postspawners (10.6% of upstream migrants) returned to the lake, and in 1994, 434 postspawners (34.6% of upstream migrants) returned downstream through the fish trap. Two distinct groups of subadult Lahontan cutthroat trout were observed moving downstream in 1994. The first group passed downstream between 27 April and 29 July and included 1188 fish (average fork length = 90 mm). Between 1 August and 31 October, 1160 fish (average fork length = 42 mm) moved downstream. Size differences of these 2 groups suggest that the 1st group comprised fish that had overwintered in Mahogany Creek, while the 2nd group were probably young-of-the-year.     

Occurrence of native Colorado River cutthroat trout ( Oncorhynchus clarki pleuriticus ) in the Escalante River drainage, Utah

Field surveys were conducted during 1997 and 1998 documenting the distribution and abundance of Colorado River cutthroat trout ( Oncorhynchus clarki pleuriticus ) in Escalante River tributaries. This documented occurrence of native trout in the Escalante River drainage of southern Utah represents an expansion of the known historic range of this subspecies as reported before the 1990s. We found 5 populations of native trout ranging in biomass from 3.0 to 104.2 kg ha -1 and occupying 13.2 km of stream of 130 km of estimated historic habitat. Current distribution and abundance of Colorado River cutthroat trout were compared to early introductions of nonnative trout stocked for sport fishing purposes. Native cutthroat trout have been displaced by nonnative cutthroat trout ( O. c. bouveri ), rainbow trout ( O. mykiss ), brook trout ( Salvelinus fontinalis ), and brown trout ( Salmo trutta ) except where they were isolated by physical or biological barriers. Displacement may have been more extensive except for the remoteness of the drainage and relatively recent introductions of nonnative trout. These conditions limited the overall amount of the drainage stocked, numbers of nonnative trout stocked, and time over which stocking occurred. Discoveries of native trout populations within the Escalante River drainage have allowed expanded conservation of this subspecies by adding new populations to what was known to exist and by increasing the known natural range of this fish.     

Gizzard shad ( Dorosoma cepedianum ) expansion and reproduction in the Upper Colorado River Basin

Gizzard shad ( Dorosoma cepedianum ) were introduced into the Colorado River Basin circa 1996 via an unintentional contaminated stocking. Gizzard shad were collected throughout much of the Upper Colorado River Basin in 2005, 2006, and 2007. These collections document a rapid range expansion of this introduced species and a threat to intact fisheries.     

Distribution and ecology of freshwater Ostracoda (Crustacea) collected from springs of Nevada, Idaho, and Oregon: a preliminary study

Fourteen freshwater ostracod species collected from 24 springs in Nevada, Idaho, and Oregon between 1991 and 1994 were classified. Their ecology, based on major water parameters (i.e., temperature, dissolved oxygen, pH, conductivity), and biogeographical distribution in North America were studied. Among these 14 species, 9 ( Ilyocypris bradyi , I. gibba , Darwinula stevensoni , Candona candida , Heterocypris incongruens , Herpetocypris reptans , H. chevreuxi , Prionocypris canadensis , P. longiforma ) are new records for Nevadas ostracod fauna, while 3 ( H. reptans , P. canadensis , and Cypria turneri ) are new species for Oregon. H. reptans , P. canadensis , and Heterocypris salina are also recorded as new for the ostracod literature of Idaho. Scottia pseudobrowniana , collected from Nevada, is a new ostracod species for the United States. The occurrence of 5 Holarctic species in the northern Great Basin area may suggest a possible historical relationship with the European ostracod fauna.     

Thermal tolerances and preferences of fishes of the Virgin River system (Utah, Arizona, Nevada)

Critical thermal maxima (CTM) and thermal preferenda of the common fishes of the Virgin River were examined. Differences in final temperature preferenda and CTM for species with low thermal lability (speckled dace, spinedace, roundtail chub) correspond well with differences in their distribution and abundance in the river. These species shifted their acute thermal preferences relatively little as acclimation temperature increased. For thermally labile species (woundfin, red shiner, desert sucker, and flannelmouth sucker), the final preferendum is a less precise indicator of probably distribution. The woundfin, an endangered fish, has a high CTM (39.5 C at 25 C acclimation) and a labile species preferendum (slope nearest 1) compared to other species in the system. The introduced red shiner likewise has a high CTM and a labile acute preferendum. In cooler temperatures, its acute preferendum shifts more rapidly than does that of the woundfin. At higher temperatures (above 15 C), the red shiner does not shift its acute preferendum as rapidly as does the woundfin. The red shiner, however, has a higher final preferendum. For thermally labile species, influence of acclimation temperature on mean preferendum, together with CTM, provides a better insight into distributional relationships within the system.     

Genetics, environment, and subspecies differences: the case of Polites sabuleti (Lepidoptera: Hesperiidae)

Circumstantial evidence is presented that suggests the Mourning Cloak undergoes regular seasonal up- and downslope movements in northern California. The species breeds at low elevations in spring and then disappears until autumn; its disappearance coincides with the appearance of fresh individuals in the Sierra Nevada alongside obvious hibernators.      

Food and habitat relationships of Claassenia sabulosa (Plecoptera: Perlidae) in the Upper Colorado River, Colorado

Streambed surveys were conducted along the upper Colorado River, Colorado, to describe the distributions of Claassenia sabulosa larvae in relation to current speed and to determine their diets. We also addressed diel feeding periodicity by sampling during both day and night. Claassenia sabulosa was more abundant in riffle habitats than in runs. A positive relationship existed between C. sabulosa abundance and stream current, with larval size increasing with current speed. Chironomidae, Baetidae, and Simulidae collectively accounted for 93% of the prey found in stonefly guts; however, these categories were not consumed equally by all C. sabulosa . Smaller C. sabulosa primarily ate chironomids, and larger individuals consumed more baetids. Only a slight difference existed in the percentage of empty guts between night- and day-collected stoneflies, and ranges of prey per gut at night were higher than those in the day, suggesting that these stoneflies may forage more intensively at night.     

The systematics of Crotaphytus wislizeni, the leopard lizards. Part III. the leopard lizards of the Great Basin and adjoining areas, with a description of a new subspecies from the Lahontan Basin

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} A general analysis of the populations of Crotaphytus wislizeni in the Great Basin is presented. A new subspecies, C. wislizeni maculosus, for the Lahontan Basin, Nevada, is described and comparisons of color pattern, some scale patterns, and skull measurements are presented.     

The Simuliidae (Diptera) of the River Oder and its tributaries,with special reference to the re-appearance of Simulium (Schoenbaueria) nigrum (Meigen) in larger rivers in Central Europe

An investigation was carried out over a five-year period into the blackfly fauna of one of the most important rivers of the North-Central European lowlands, the Oder, together with its major tributaries (Nysa, Stobrawa, O?awa, Barycz, Bobr, Kroisa, Lausitzer Neisse, Warta, Notec), from its source in the Oder Hills to its mouth in the Baltic Sea. Thirteen species were found. The two dominant indicator species, Simulium (Simulium) reptans (Linnaeus) and Simulium (Schoenbaueria) nigrum (Meigen), develop populations of plague proportions within this catchment area. Blackflies of the subgenus Schoenbaueria Enderlein have not been found in Germany or Poland for more than 70 years. However, since 1997, the species S. (Sch.) nigrum was found in the River Oder in enormous numbers together with S. (S.) reptans, and in the vicinity of their breeding sites in Poland and eastern Germany both species are serious pests of man and grazing animals. Notes are given on the biology, distribution and habitat preferences of S. (Sch.) nigrum. The paper concludes with a comparison of the River Oder with some other Central European rivers in respect of its blackfly fauna, together with data on the phenology of the two indicator species.     

The geometric morphometrics and condition of Pontic shad,Alosa immaculata (Pisces: Clupeidae) migrants to the Danube River

Anadromous fish could have intraspecific groups with different life histories; identification of these is very important for management and conservation. Geometric morphometrics represents a quick and cost-effective method to identify such intraspecific groups. In this study, geometric morphometrics of Pontic shad (Alosa immaculata) migrants from the Danube River were investigated, as was Fulton's condition factor (K), hepatosomatic index (HSI) and gonadosomatic index (GSI). Pontic shad specimens were collected during April and May of 2004 and 2006. The sample comprised four groups (65 males and 56 females in 2004; 110 males and 78 females in 2006). Geometric morphometrics revealed differences in shape that were statistically significant for both year (nested analysis of variance: F = 13.84; p < 0.001) and sex (nested analysis of variance: sex nested in year, F = 1.71; p < 0.01). The major differences between years were in head shape and position of fins. The most significant difference between females and males was in the dorsolateral expansion of the mid-body section with emphasis on the higher dorsal part of the body. Values for K in this work (0.65–0.70) were the lowest recorded for Pontic shad in the Danube River. Additional investigations involving both geometric morphometrics and molecular genetics are necessary to confirm the presence of races. This could be important information for conservation purposes as Pontic shad is listed as Vulnerable on the International Union for Conservation of Nature list.     

Vestimentiferans (Pogonophora) in the Pacific and Indian Oceans: a new genus from Lihir Island (Papua New Guinea) and the Java Trench,with the first report of Arcovestia ivanovi from the North Fiji Basin

Explorations by the German Research Vessel Sonne in the fore-arc and back-arc basins of the western Pacific Ocean have collected vestimentiferan tube worms from both warm vent and cold seep sites. Edison Seamount is a small volcanic cone on the southern flank of Lihir Island, in the Tabar-Feni island chain. Beds of vesicomyid clams on the summit (1450 m depth) are associated with hydrothermal effluent, whereas an uplifted scarp (1600 m depth) nearby is covered by low temperature gas-rich sediments. A methane anomaly has been detected in the water column above the scarp. The benthic fauna includes vestimentiferan tubeworms and bathymodiolid mussels. Bottom photographs show that the vestimentiferans occur singly or in small groups. Four specimens were collected by TV-guided grab. They are described as a new species of a new genus, related to the cold-seep genus Escarpia, of the family Escarpiidae. A single specimen obtained from the landward slope of the Java Trench (1500m) is identified as the same species, extending its area of distribution by some 6000 km westward. Arcovestia ivanovi, already known from hydrothermal vents in the Manus Basin, has now been obtained from a hydrothermal site in the North Fiji Basin.     

The bryozoan genus Conopeum (Electridae) in New Zealand,with description of a new species and discussion of the morphological and genetic characters of Conopeum seurati (Canu, 1928)

ABSTRACT

The status of Conopeum Gray, 1848 in New Zealand is clarified, confirming the presence of three living species – one a naturalised alien, one new to science, and a third that is also known in the Pleistocene. Conopeum seurati (Canu, 1928), a Mediterranean-European species, is naturalised at three localities in New Zealand – Opua, Whangarei Harbour and Whanganui Inlet. Conopeum antipodum n. sp., previously confused with C. seurati, is an estuarine species distributed from Kaipara Harbour to Lyttelton Harbour and is also found in Te Whanga Lagoon at Chatham Island (all New Zealand localities). Conopeum oretiensis Uttley, 1951, first described from Foveaux Strait, is known as far north as Kaipara and Manukau Harbours and is known as a Pleistocene fossil from Napier, New Zealand. There is one other solely fossil New Zealand species – Plio-Pleistocene Electra ongleyi Brown, 1952 is transferred to Conopeum. Sequence data from the 18SrDNA locus confirm that Conopeum antipodum n. sp. is resolved within Conopeum and is distinct from C. seurati.

http://www.zoobank.org/urn:lsid:zoobank.org:act:4FED6730-1C70-4420-B1DA-F1D9046221DF http://www.zoobank.org/urn:lsid:zoobank.org.pub:5C130A99-0869-44A2-885C-338005FBCE07     

The anatomy and attachment mechanism of the haptor of a Capsala sp. (Platyhelminthes: Monogenea: Capsalidae) on the blue marlin,Makaira nigricans (Istiophoridae)

The muscular anatomy and fine structure of the haptor of a monogenean, Capsala sp., together with an observational distribution study, are described from specimens collected from the dorsolateral and ventral surfaces of the blue marlin, Makaira nigricans. The haptor is composed of seven loculi, which are arranged around a central pair of accessory sclerites. Marginal hooklets and hamuli were not observed. The presence of an outline left by the haptor on the host's skin and the lack of evidence of an adhesive secretion suggested that the haptor attaches primarily by suction. Tendons originating in the extrinsic peduncle muscles insert, via a proximal notch in the accessory sclerites, into the basal tegumental lamina on the ventral surface of the haptor. On contraction the centre of the haptor is thought to be drawn upwards both directly by the extrinsic tendons in the haptoral wall but also by the accessory sclerites which are brought into a vertical position. This increases the volume beneath the haptor, consequently reducing the pressure and thus producing suction. The ribbed marginal valve prevents the inward movement of water. Intrinsic circular and radial muscles in the haptoral wall are also thought to produce suction by drawing the haptoral wall inwards, again increasing the volume beneath and causing a pressure reduction. It is suggested that interconnecting fibres observed between the intrinsic muscles may store elastic energy, allowing Capsala sp. to maintain suction attachment without having constantly to contract its muscles. Papillae on the inner ( = ventral) surface of the haptor are suggested to aid attachment by firstly spreading the negative pressure over the inner surface of the haptor and, secondly, through resisting the shear forces encountered as the fish swims. Both functions are achieved by increasing the surface area of contact with the host's skin, and therefore the frictional forces. Theoretical estimates of the suction efficiency indicate that suction is double the maximum theoretical drag forces which would be experienced by Capsala sp. when M. nigricans is swimming at speeds of both 1 and 20 m s^?1 and suggests that suctorial attachment is efficient. The distribution of Capsala sp. is not thought to be restricted by the surface topography of the host, demonstrated by the fact that individuals were located in both the roughest and smoothest areas of the marlin's skin surface. Distribution is therefore thought to be influenced by other factors such as hydrodynamics, nutritional value of the attachment site, immunological restrictions or cross‐fertilization between parasites.     

The male of Culicoides reevesi Wirth, with a redescription of the female and new seasonal activity, distribution, and biting records (Diptera: Ceratopogonidae)

The previously unknown male of the biting midge, Culicoides reevesi Wirth, is described and illustrated; the female is also redescribed and this species is reassigned to the leoni group. Previously known from California, Arizona, and New Mexico, C. reevesi is recorded for the 1st time from Utah ( new record ). Females of this aggressive, hematophagous species were collected while biting humans during evening crepuscular periods in California. Females exhibited a strong attraction to CO 2 traps, and seasonal surveillance demonstrated that host-seeking occurred from late May until mid-October in both California and Utah. Small numbers of males were also collected in CO 2 traps; however, both sexes showed little attraction to ultraviolet and incandescent light traps.     

Distribution of the milliped genus Narceus Rafinesque, 1820 (Spirobolida: Spirobolidae): occurrences in New England and west of the Mississippi River; a summary of peripheral localities; and first records from Connecticut, Delaware, Maine, and Minnesota

The milliped genus Narceus Rafinesque, 1820 (Spirobolida: Spirobolidae) occupies parts or all of 2 Canadian provinces, Québec and Ontario; every U.S. state east of the Mississippi River; and 9 states to the west including Minnesota, Iowa, Missouri, Arkansas, Louisiana, Nebraska, Kansas, Oklahoma, and Texas. Records are detailed for the "western" states and New England and include the first from Minnesota, Connecticut, Delaware, and Maine; occurrence is projected for southeastern Minnesota and the Delmarva Peninsula. The genus presently comprises 2 valid species that are endemic to Florida— N. gordanus (Chamberlin, 1943) and N. woodruffi Causey, 1959—and 2 of uncertain status that occur throughout the generic range and are referenced as the " N. americanus/annularis complex"; geographic evidence suggests greater diversity, particularly in the south, and a 2nd generic revision is in order to update the existing one by Keeton (1960). Records cluster within a large, semicontinuous area whose northern, southern, and western range extremes, respectively, are Saint-Nicolas, Lévis Census Division, Québec; Key West, Monroe County, Florida, and northeastern Duval County and Rockport, Aransas County, Texas; and Garner State Park, Uvalde County, Texas. The eastern limit is the Atlantic Ocean, and records are available from Cape Cod and Tuckernuck Island, Massachusetts; Long Island, New York; Cape Hatteras, North Carolina; and James Island, South Carolina. The projected western boundary, based on peripheral localities, angles southwestward from Omaha, Nebraska, to Uvalde County; and the northern boundary passes through central Iowa and Wisconsin (encompassing the Door Peninsula) and the southern periphery of the Upper Peninsula of Michigan. The lone Minnesota locality, from Lyon County in the southwest, lies substantially north of the projected border in Iowa and well west of the expected area of occurrence in southeastern Minnesota. The northernmost record west of the Mississippi River, it may represent an allopatric population that extends westward into eastern South Dakota.