Rhinichthys Cataractae Research Articles

Comparison of the breeding habits of two subspecies of longnose dace, Rhinichthys cataractae

Reproductive behavior of the longnose dace, Rhinichthys cataractae dulcis, from Alouette River, British Columbia, is described and compared with the eastern subspecies, Rhinichthys cataractae cataractae. Color differences between breeding males of the two subspecies are striking. Rhinichthys c. cataractae males display bright crimson patches on the ventral surface but these are lacking in R. c. dulcis males. The former breeds during daylight while the latter breeds at night. Although breeding behavior patterns of the two subspecies are almost identical, slight differences do exist and are correlated with diurnal versus nocturnal breeding.

The North and Central American Species of Rhabdochona Railliet 1916 (Nematoda: Rhabdochonidae) of Fishes, Including Rhabdochona canadensis sp.nov.

The systematics of the representatives of the genus Rhabdochona, parasitic in fishes of North and Central America, is revised. Rhabdochona cascadilla Wigdor 1918, R. kidderi Pearse 1936, R. decaturensis Gustafson 1949, R. cotti Gustafson 1949, R. ovifilamenta Weller 1938, R. milled Choquette 1951, and R. canadensis sp.nov. are considered as the valid species of this region. The first six species are redescribed and illustrated. The new species, R. canadensis, is described from the cyprinids Hybopsis gracilis (flathead chub; type host), H. plumbea (lake chub), and Rhinichthys cataractae (longnose dace) of Alberta; the latter form is characterized largely by the presence of one or two long filaments at each pole of the eggs, by 14 teeth in the prostom, by the presence of the cuticular spike at the tip of the tail, and by the character of the spicules. The species R. pellucida Gustafson 1949 is regarded as a synonym of R. cascadilla Gustafson 1949, and R. laurentiana Lyster 1940 as a synonym of R. ovifilamenta Weller 1938. Rhabdochona serrata (Wright 1879) Ko and Anderson 1969 is transferred to the genus Cystidicola as species inquirenda. The hosts and geographical distribution of the current members of the genus are reviewed. The paper is supplemented by a key for the identification of the species parasitic in fishes of North and Central America.

Reproductive Isolation Between Two Sympatric Dace, Rhinichthys atratulus and R. cataractae, in Manitoba

The Mink and Valley rivers, Manitoba, contain two sympatric species of dace (Cyprinidae: Rhinichthys). These fishes, although interfertile, have never been reported to hybridize in nature.Seasonal isolation is only partially developed, since overlap in time of spawning exists. During spawning, adults of the two species tend to occupy different habitats, the Great Lakes longnose dace Rhinichthys cataractae cataractae being most abundant in water velocities faster than 45 cm/sec and the western blacknose dace R. atratulus meleagris in water velocities less than 45 cm/sec; but some overlap exists. However, the place of spawning of the two species is distinctly different. Nests of longnose dace were found in water velocities exceeding 45 cm/sec with large stones, whereas nests of blacknose dace were found in slower water velocities in gravel. The patterns of spawning behaviour of these two cyprinids reveal marked differences and obvious incompatibilities. Males of both species actively defend territories prior to spawning but show distinct preferences for conspecific females over other females. Observations further indicate that females are receptive only to patterns of courtship behaviour shown by males of their own species.The combination of different places of spawning and patterns of behaviour is considered to be a powerful barrier to hybridization.

Lactate Dehydrogenase Isozymes in Longnose and Blacknose Dace (Rhinichthys cataractae and R. atratulus) and Their Hybrid

Electrophoresis of tissue extracts of both longnose and blacknose dace reveals five isozymes corresponding to tetramers of heart and muscle type subunits. The species are readily distinguished by the greater electrophoretic mobility of longnose dace isozymes that contain heart type subunits. The F1 hybrid displays the multiple band pattern expected in a fish able to produce two kinds of heart subunit. In addition a variant type of muscle lactate dehydrogenase has been detected in the longnose dace.

Adjustment of Buoyancy by Longnose Dace (Rhinichthys cataractae) in Relation to Velocity of Water

The buoyancy of longnose dace (Rhinichthys cataractae) is correlated with the velocity of water in which they are living. Swimbladders from fish collected in rapids of streams and rivers are smaller in volume than in those fish collected from still water. Laboratory experiments on yearling and older fish show that individuals alter their buoyancy by changing the volume of their swimbladder. Buoyancy depends on velocity of water and size of fish. Longnose dace adjust their buoyancy rapidly in response to changes in velocity of water. They can decrease their buoyancy to adapt to an increase in velocity of water in 3 hr. A complete adjustment requires 4 days. Fish with access to the surface can increase their buoyancy in response to reduced velocities by completely inflating their swimbladders in less than 24 hr. Fish without access to the surface require 48 hr to complete the same adjustment. Thus, longnose dace have a functional gas gland even though they are physostomes. The gas gland does not function during the early stages of life after hatching. Alevins come to the surface to fill initially their swimbladders. The ability to adjust buoyancy rapidly is an adaption to life in rivers and streams by fishes that live mostly in swift-flowing waters but are sometimes forced to live temporarily in reduced current when the volume of water flowing is diminished.

The monogenean parasites of Canadian freshwater fishes.

A brief history of work performed on the Monogenea of Canadian freshwater fishes is recounted; a list indicating the host – monogenean parasite relationships of Canadian freshwater fishes is included. Dactylogyrus albertensis sp. nov., recovered from the gills of the flathead chub, Hyhopsis gracilis (Richardson), is described. Two additional known parasite species are recorded for Canada: (1) Pseudomurraytrema muelleri Price, 1967, recovered from Catostomus commersoni (Lacépède) and (2) Dactylogyrus banghami Mizelle and Donahue, 1944, recovered from Rhinichthys cataractae (Valenciennes). Hosts were collected from the Milk River in Alberta.

Food Habits of the Longnose Dace, Rhinichthys cataractae

Samples of longnose dace, Rhinichthys cataractae, and bottom organisms were taken approximately every two weeks from 9 July to 5 September 1963, from a 56,000 ft2 riffle of the Yellowstone River near Emigrant, Montana. The fish were divided into three size groups (0-49 mm, 5069 mm, and 70-100 mm) for the analysis of digestive tract contents. The frequency occurrence of all organisms in the fish digestive tracts, per cent volume and average number of insects were considered for each of these groups. Baetidae had the highest per cent volume and the highest average number in each size group except that Tendipedidae had the highest average number in the 50-69 mm size group. Algae had the highest frequency occurrence in the 0-49 mm group. Tendipedidae was highest in the 50-69 mm group, and Baetidae and Tendipedidae were equally high in frequency occurrence in the 70-100 mm group. Seasonal variation of food was about the same in all three size groups. Forage ratios were calculated for each size group. Baetidae had the highest forage ratio with 3.9, 5.0, and 6.8 in the small, medium, and large size groups, respectively. The only other family with a ratio greater than 3.0 was Simuliidae which had 5.3 in the 70-100 mm group but less than 1.0 in the other two groups. The ratios of Baetidae, Siphlonuridae, and Simuliidae were highest for the largest size group of fish while the ratios of Tendipedidae and all Plecoptera were highest for the smallest size group of fish. While some of the bottom organisms were too large for the fish to eat, the ones found in the digestive tract contents were generally those that were most available and abundant.

HYBRIDIZATION BETWEEN TWO CYPRINID FISHES, HYBOPSIS PLUMBEA AND RHINICHTHYS CATARACTAE, IN ALBERTA

Five hybrids between Hybopsis plumbea and Rhinichthys cataractae seined from Upper Kananaskis Reservoir, Alberta, were intermediate in most of the characters examined which differ between their parental species. Hybrids of each sex were present. Environmental changes may have been conducive to the hybridization. Marked physical changes occur annually in Upper Kananaskis Reservoir and Hybopsis plumbea and probably Rhinichthys cataractae were introduced.

Some Experimental Fish Hosts of the Strigeid Trematode Bolbophorus confusus and Effects of Temperature on the Cercaria and Metacercaria

Experimental studies were conducted on the digenetic trematode, Bolbophorus confusus (Krause, 1914) Dubois, 1935, to test host specificity in fish and the effect of temperature on the cercaria and metacercaria. Typical infections followed laboratory exposures of the following fishes: Salmo gairdneri, Salmo trutta, Salvelinus fontinalis, Prosopium williamsoni, Pimephales promelas, Hybopsis gracilis, Rhinichthys cataractae, Catostomus commersoni, Pantosteus platyrhynchus, Lepomis macrochirus, and Gambusia affinis. Cercarial penetration occurred in Ictalurus punctatus and Cottus bairdi, but metacercarial development was atypical. Maximum cercarial penetration of fish occurred between 66 and 85 F. Invasive ability was markedly reduced between 55 and 65 F and very few penetrations occurred below 54 F. Metacercariae developed rapidly at 70 F. No metacercarial development was found in fish exposed to cercariae at 70 F and then held at 40 to 42 F. Some metacercariae were observed to develop normally when fish treated in the above manner were returned to 70 F, after being held at 40 to 42 F for 1 month. Water temperature apparently plays a major role in the distribution of the metacercaria of B. confusus (common only in one lake) in southwestern Montana. The digenetic fluke Bolbophorus confusus (Krause, 1914) Dubois, 1935, is established in Meadow Lake in southwestern Montana (Fox, 1962). Although this fluke is reported to be common in Europe, the metacercaria had not been previously reported in North America. It has not been found in other lakes in the Meadow Lake vicinity. In Europe, Dubois (1938) reported the metacercaria of this paarsite in the following fishes: rudd (Scardinius erythropthalmus), id (Idus idus), bream (Abramis brama), flat bream (Abramis blicca), northern pike (Esox lucius), perch (Perca fluviatilis), and mullet (Mugil saliens). He reported the final hosts to be the pelicans Pelecanus onocrotalus and Pelecanus crispis in Europe, and the white pelican (Pelecanus erythrorhynchos) in North America. In Meadow Lake, the metacercariae are found in rainbow trout (Salmo gairdneri), brown trout (Salmo trutta), arctic grayling (Thymallus arcticus), longnose sucker (Catostomus catostomus), and white sucker (Catostomus commersoni). Fox (1962) observed a marked difference in the number of B. confusus metacercariae Received for publication 17 February 1965. * This study was supported by Grant AI-05055-03 from the U. S. Public Health Service, NIH, Bethesda, Maryland. Contribution from the Montana State University Agricultural Experiment Station Project No. MS-844 Paper No. 684 Journal Series. found in brown and rainbow trout from Meadow Lake. All brown trout examined were infected with an average of 194 cysts per fish. Cysts were found in 25 of 30 rainbow trout examined and averaged only 34 per fish. The difference in the degree of infection between the trout and the fact that B. confusus metacercariae are not reported in fish from nearby lakes, formed the basis for this investigation. The objectives were to study the host specificity of B. confusus metacercariae in fish and to find an explanation for the prevalence of the parasite in Meadow Lake fish. Although the snail host and cercaria of B. confusus were not known at the time the parasite was found in Meadow Lake, the complete life cycle has since been determined by Fox (1965). It is briefly as follows: the adult fluke is found in the anterior intestine of the white pelican. The eggs pass out with the feces into the water and hatch after about 15 days. The resulting ciliated miracidia penetrate the planorbid snail, Helisoma trivolvis. Sporocysts develop in the snail producing large numbers of cercariae. After leaving the snail, the cercariae penetrate fish and encyst in the musculature as metacercariae. When eaten by a pelican, the metacercariae develop to patent adults within a few days. MATERIALS AND METHODS Numerous attempts were made to collect snails (Helisoma trivolvis) from Meadow Lake in the spring and early summer of 1963, but none were

Infections of the Hemoflagellate, Cryptobia salmositica Katz, 1951, in Freshwater Teleosts of the Pacific Coast

Infections of Cryptobia salmositica Katz, 1951, are common and widely distributed in freshwater teleosts of the Pacific coast from southern British Columbia to northern California. The hemoflagellates are reported from 16 species of fish, representing four families and including 10 new hosts. The most susceptible hosts, as indicated by the incidence and intensity of infection, are the pink (Oncorhynchus gorbuscha) and coho (O. kitsutch) salmon, the torrent (Cottus rhotheus) and coastrange sculpin (C. aleuticus), and the longnose dace (Rhinichthys cataractae). The infected fish are typical cold-water species, occurring only in streams of generally low temperatures, graveled beds, and moderate to swift flowing currents. In this natural environment, the fish are associated with Piscicola salmositica (Meyer, 1946), the only known leech vector of the hemoflagellates. It is suggested that but one distinct species, C. salmositica, occurs in the blood of the various teleost fishes in this geographically restricted area in association with a common vector.

Effects of Fish Introductions and Hydroelectric Development on Fishes in the Kananaskis River System, Alberta

Changes occurred in the abundance and distribution of fishes in the Kananaskis River system, Alberta, in conjunction with fish introductions and hydroelectric development. Data from surveys from 1936 to 1961 indicate the probable chronology of events.Dolly Varden (Salvelinus malma), brook trout (S. fontinalis), cutthroat trout (Salmo clarkii), and rainbow trout (S. gairdneri) decreased in abundance, probably due to the introduction of brown trout (Salmo trutta), longnose suckers (Catostomus catostomus), and white suckers (C. commersonii), to the cooling of the Kananaskis River from reservoir construction, and to sport fishing. Hybridization between rainbow and cutthroat trout was also important in the decrease of the latter species. After introduction by man, brown trout, rainbow trout, longnose suckers, white suckers, lake chub (Hybopsis plumbea), and longnose dace (Rhinichthys cataractae) greatly increased in abundance. Prior to the increase in numbers of white suckers, a reduction in the numbers of longnose suckers occurred in Lower Kananaskis Reservoir. Little change in the distribution of mountain whitefish (Prosopium williamsoni), longnose dace, and brook sticklebacks (Culaea (= Eucalia) inconstans) occurred over the 25 years. Changes in the physicochemical environment and invertebrate fauna in the reservoirs appeared to be of secondary importance to the interaction among fish in causing the changes in species abundance and distribution.

Comparative Ecology of Two Sympatric Species of Dace (Rhinichthys) in the Fraser River System, British Columbia

Age, growth and food habits of leopard dace (Rhinichthys falcatus) in the lower Fraser River are described. Although recently emerged leopard dace and longnose dace (Rhinichthys cataractae) occur together in regions of slow or no current along the river margin, older longnose dace soon begin to occupy regions of higher water velocity. Yearling and older leopard dace remain predominantly in areas of little current. Laboratory experiments in a stream tank demonstrate a strong current preference in longnose dace fry, yearlings and adults. Leopard dace of comparable size show no preference for water current. The swimbladder volume of yearling and adult longnose dace is much lower than that of leopard dace, possibly an adaptation of the former species to occupation of riffle habitat. Temporary coexistence of the two closely related species in the same niche is discussed briefly.

Tooth Replacement and Food of the Cyprinid Notropis cerasinus from the Roanoke River, Virginia

Examination of 504 pairs of pharyngeal arches of the cyprinid Notropis cerasinus collected monthly from the Roanoke River near Shawsville, Virginia, June 1955-May 1957, revealed a constant 3-1-2-4 pattern of tooth replacement. This pattern remained unchanged throughout the seasons. The primary food items found in the stomachs of 578 specimens were chironomids, simuliids, trichopterids and coleopterids. We wish to present data on the tooth replacement pattern and sequence in the cyprinid Notropis cerasinus (Cope) and to consider whether the former are influenced seasonally by the types of food eaten. The life history study of Stagner (1959), based on the same specimens examined herein (which were loaned to her and constitute part of the collections by the senior author from the Roanoke River at Shawsville, Virginia), has shown that N. cerasinus has a life span of four years with males growing faster than females. The males are 35 mm in total length as young of the year; 55 mm when one year old; 65 mm when two years old, and 80 mm when 3-4 years old. To date this is the only study, other than those concerning distribution (Fowler, 1945; Raney, 1950; Moore, 1957), regarding this species. Evans and Deubler (1955) have presented, for a single collection of Semotilus atromaculatus and Clinostomus elongatus, the only tooth replacement data for North American cyprinid fishes and have ably reviewed the meager literature on pharyngeal tooth replacement. Belogurov (1940) has commented on the tooth replacement pattern in European carp. Horoszewicz (1960) has defined the changing shapes of twenty-one European species of cyprinids. Recently Barankov (1960) has shown that three species of wolffish have seasonal patterns of tooth shedding while Vladykov and Mukerji (1961) have called attention to the various changing forms of infraoral lamina in landlocked Petromyzon marinus with age. Evans (1950) noted the arrangement of replacement teeth in the carp, Cyprinus carpio; longnose dace, Rhinichthys cataractae; creek chub, Semotilus atromaculatus; and golden shiner, Notemigonus c. crysoleucas, all collected near Ithaca, New York. Trautman and Hubbs (1948) investigated seasonal effects on the replacement of teeth in Esox and recorded tooth positions. Recently Edmund (1960) has contributed new and startling data on jaw tooth replacement of reptiles and other poikilotherms. Individuals of Notropis cerasinus were collected monthly from June, 1955 through May, 1957, from a 1.5-mile section of the Roanoke River 1 Contribution No. 208, Natural Resources Institute of the University of Maryland, Solomons, Maryland.

Age, Growth, and Food of the Longnose Dace, Rhinichthys cataractae, in Northwestern Pennsylvania

Age, Growth, and Food of the Longnose Dace, Rhinichthys cataractae, in Northwestern Pennsylvania

The American Cyprinid Fish Notropis germanus Hay Interpreted as an Intergeneric Hybrid

The systematization of our knowledge of the immense fresh-water fish faura of eastern North America is being advanced not only by the discovery of new forms and the reclassification of previously known species, but also by the elimination from the system of nominal species known only from the original accounts. Some particularly troublesome forms are eliminated through being interpreted as interspecific hybrids, as was done when Raney (1940) demonstrated that Rhinichthys bowersi Evermann and Goldsborough was based on a hybrid between Rhinichthys cataractae (Valenciennes) and Nocomis micropogon (Cope). Such action, when taken on reliable grounds, not only clarifies the systematics, but also contributes to the rapidly growing body of facts and interpretations regarding hybridization in nature between fish species. The present study clears the nominal species Notropis germanus Hay (1887: 252-253) from the system and adds a new interspecific hybrid, Hybognathus hankinsoni X Notropis beterolepis. A somewhat similar combination, H. placita X N. girardi, has just been recorded by Cross (1950: 128, 141). A nomenclatorial complexity may arise from the circumstance that NOtropis germanus was proposed prior to the naming either of Hybognathus hankinsoni Hubbs (in Jordan, 1929: 88) or of the still unnamed southern subspecies of Notropis heterolepis Eigenmann and Eigenmann that is characterized by the complete or nearly complete lateral line and that may be involved in the hybrid combination. There is apparently no rule or recommendation in regard to the availability of a name regularly proposed for a nominal species that is later interpreted as an interspecific hybrid. It might be argued that the name was based on a complex and should be associated with the element of the complex to be selected by the first author who recognizes the situation and unequivocally makes the selection. Such action has been taken in respect to names based on subspecific intergrades and the distinction between these and interspecific hybrids is often subjective and tenuous (Hubbs, 1943). On the other hand, names based on interspecific hybrids are not applicable to true populations and the type specimens would not be representative. More doubt, confusion and instability would arise from accepting than from rejecting names interpreted as based on interspecific hybrids. It is therefore recommended that these names be regarded as unavailable for either parental species. Such apparently has been the practice in both botany and zoology.