Ichthyological Survey Research Articles

Ichthyological survey and review of the checklist of fish fauna of Arunachal Pradesh, India

One hundred thirty eight fish species were collected during a systematic survey of 35 rivers in Arunachal Pradesh state, India, in March 2004 to March 2008. Based on this survey and on literature review we developed a checklist with 213 fish species for the state. We have added 43 species to the previous record of 170 species. This study confirmed the occurrence of five new species described by previous investigations and encompasses the discovery of two new species, although the taxonomic status of 27 species is uncertain and requires additional study.

Extension of range of the Marine Puffer Fish Chelonodon patoca (Tetraodontiformes: Tetraodontidae) to freshwater habitat of Kerala, India

Chelonodon patoca is a marine puffer fish common along the Coromandal Coast of India. It has also been reported in the Aghnashini River in Karnataka state, a freshwater habitat. During a recent ichthyological survey five specimens of Chelonodon patoca were collected in another freshwater habitat, the Payaswani River in Kerala state. These specimens document an extension in the distributional range from Karnataka to Kerala state in peninsular India.

Fish fauna of small streams of the Catua-Ipixuna Extractive Reserve, state of Amazonas, Brazil

This study was conducted in an Amazonas state conservation unit, the Catuá-Ipixuna Extractive Reserve (Catuá-Ipixuna RESEX). The main purpose was to provide an ichthyological survey of its small streams, all them tributaries of the Solimões River. Nine small streams (up to 4 m width and 1 m depth) were sampled in September 2006. A total of 1,525 specimens were captured, belonging to 78 species, 24 families and eight orders. Eight species had higher abundances and represented altogether 61.4 % of all collected specimens (Hemigrammus belotii, Microphilypnus amazonicus, Physopyxis ananas, Apistogramma agassizii, Elachocharax pulcher, Apistogramma cf. cruzi, Gladioglanis conquistador and Copella nigrofasciata). Based on the high number of singletons and doubletons present in our samples, as well as the estimated number of species for those streams (106 spp.), we believe that the total fish species richness present in the Catuá-Ipixuna Extractive Reserve may be considerably higher than indicated by our samples. This seems especially true when considering the dimensions of the Catuá-Ipixuna RESEX and the dense hydrographic network present in the area.

Effect of introduced species and habitat alteration on the occurrence and distribution of euryhaline fishes in fresh- and brackish-water habitats on Aruba, Bonaire and Curaçao (South Caribbean)

We conducted an ichthyological survey during the dry season of 2006 on the semi-arid islands of Aruba, Bonaire and Curaçao to provide information on species composition, richness and distribution in natural and non-natural aquatic habitats. The dry season species assemblages (N = 9 species) comprised less species than the wet seasons, and these data refine our knowledge of the indigenous fish fauna and its refuge localities during phases of drought and ensuing high salinity. A hierarchical cluster analysis reveals that the three islands have different species compositions with Curaçao being the most diverse, probably due to its having the most habitats and freshwaters present throughout the year. Species richness was unrelated to salinity and species diversity was highest in canalised streams. In the dry season fewer amphidromous species are present than in the wet season. We found no significant effect of human-induced changes on the presence or absence of fish species in the Netherlands Antilles. The presence of exotic species (including Xiphophorus helleri on Aruba, a first record for this island, and Oreochromis mossambicus and Poecilia reticulata occurring on all three islands) did not have a clear effect on the presence of indigenous species, nor did human alteration of the habitats have an influence on the occurrence of fish species.

A new Aspidoras (Siluriformes: Callichthyidae) from rio Paraguaçu basin, Chapada Diamantina, Bahia, Brazil

During a recent ichthyological survey in Chapada Diamantina, Estado da Bahia, Brazil, a new, very distinctive Aspidoras was discovered in tributaries of the upper rio Paraguaçu. The new taxon differs from its congeners mainly in having: a poorly-developed pigmentation pattern, restricted to minute scattered blotches on dorsal region of head and body, but grouped in small, irregular blotches along the lateral body plate junction; four or five caudal vertebra, anterior to compound caudal centrum, with neural and haemal spines placed posteriorly, close to post-zygapophyses; and post-zygapophyses of the precaudal vertebrae without dorsal expansions connected with their respective neural spines. The new species shares with Aspidoras velites dorsolateral body plates not touching their counterparts dorsally, and infraorbital bones with reduced flanges that are restricted to the latero-sensory canal. Both of these are considered reductive character states, probably indicating a paedomorphic condition to both species. The new species is also compared to Aspidoras maculosus, a congener which bears the most similar color pattern and is geographically closest to the new species.

Physico-chemical characteristics of South African estuaries in relation to the zoogeography of the region

Selected physico-chemical characteristics of estuaries within three biogeographic regions of South Africa were described and compared using data from an extensive ichthyological survey of the region. The results indicate that estuaries within each zoogeographic region have distinctive physico-chemical characteristics that could be related to regional variations in climate and oceanographic conditions. Estuarine temperatures follow the trend for marine coastal waters, decreasing from the subtropical east coast, along the warm-temperate south coast and up the cool-temperate west coast. Low rainfall and runoff together with high seawater input and evaporative loss results in high salinities and low turbidities in warm-temperate estuaries while high rainfall and runoff results in reduced salinities and high turbidities, particularly in subtropical estuaries.

Physico-chemical characteristics of South African estuaries in relation to the zoogeography of the region

Selected physico-chemical characteristics of estuaries within three biogeographic regions of South Africa were described and compared using data from an extensive ichthyological survey of the region. The results indicate that estuaries within each zoogeographic region have distinctive physico-chemical characteristics that could be related to regional variations in climate and oceanographic conditions. Estuarine temperatures follow the trend for marine coastal waters, decreasing from the subtropical east coast, along the warm-temperate south coast and up the cool-temperate west coast. Low rainfall and runoff together with high seawater input and evaporative loss results in high salinities and low turbidities in warm-temperate estuaries while high rainfall and runoff results in reduced salinities and high turbidities, particularly in subtropical estuaries.

Ichthyological Survey of Lake Taihu during 2002-2003

2002-2003年对太湖鱼类学进行了调查,共采集鱼类48种(和亚种),隶属于15科、18目。比上世纪50至70年代调查的103种减少了55种。分析了鱼类种类减少的原因,主要是上世纪60年代环湖大堤和闸坝建设,阻隔了太湖和长江间的交通,以及水草湖区面积的萎缩和沉水植物的急剧减少。;48 species of fishes belonging to 15 family were collected and identified.Predominating among them are members of Cyprinidae, which comprise over 54% of the total number of species.From every aspect, ichthyofauna of Lake Taihu represent the typical one inhabiting stagnant water-bodies of the lower Changjiang(Yangtse) Valley.According to the survey of fish species made in 1950-1981, there were no less then 103 species in the lake.In 2002-2003, only 48 species were obtained from the lake.The cause of the diminution of fish species was chiefly that a partitive dike was built round the lake in the 1960s, thus severing the intercommunication between the Changjiang River and the Lake Taihu.The impoverishment of the submerged vagetion resource (such as the reclamation of land from the lake and fish-pen in the lake and so on ) also led to the diminution of species.On the other hand, the measures for conserving the fish resource and managements for increasing productivity of the lake are discussed.

Annotated Catalog of Type Specimens in the Illinois Natural History Survey Fish Collection

The Fish Collection of the Illinois Natural History Survey (INHS) dates back to the late 1800s and the extensive surveys of Illinois fishes led by Dr. Stephen A. Forbes, director of the Survey's predecessor, the Illinois State Laboratory of Natural History (ISLNH). From 1876 to 1903 Forbes, assisted by his esteemed colleague Robert E. Richardson and numerous field and laboratory personnel, collected and preserved over 200,000 specimens from more than 450 localities distributed in 93 of the 102 counties of Illinois. During this time, the ISLNH Collection served as the basis for several catalogs of Illinois fishes (Nelson 1876; Jordan 1878a; Forbes 1884; Large 1903), and provided material for the description of at least 25 species. This work culminated in the classic Fishes of Illinois written by Forbes and Richardson, published by the Survey in 1909 and reprinted in 1920 (although no publication date is given for the original volume, H.C. Oesterling, former INHS editor, lists the date as 1909 in Howard 1932:46). Accompanied by a separate atlas of distribution maps of 98 species, this comprehensive treatment of the state's ichthyofauna still is recognized as one of the finest publications on fishes. The INHS Fish Collection was expanded by Dr. Philip W. Smith, who worked as a systematic biologist at the Survey from 1942 until his retirement in 1979 (Burr and Page 1987). Over a period of 1 1 years from 1962 to 1972, Smith assembled a large collection of fishes from Illinois and neighboring states. The ichthyological surveys conducted by Smith, his students, and INHS staff led to the publication of a second Fishes of Illinois (Smith 1979). Smith's monograph provided identification keys, information on the ecology and taxonomy of Illinois fishes, and detailed distribution maps that documented changes in the state's fish fauna that had occurred since the survey of Forbes and Richardson. The size and geographic scope of the INHS collection have been considerably expanded in the past three decades; the collection now contains about 7 1 1 ,000 cataloged specimens (over 7 1 ,000 lots) of more than 1,800 species. A recent literature survey identified over 250 publications citing the use of INHS specimens over the past 40 years. Included are two publications that have greatly advanced both the professional and popular understanding of North American fishes: the Handbook of Darters (Page 1983) and A Field Guide to Freshwater Fishes of North America North of Mexico (Page and Burr 1991).

The diet of the Antarctic fish Trematomus newnesi Boulenger, 1902 (Nototheniidae) from Terra Nova Bay, Ross Sea

A coastal ichthyological survey was carried out in Terra Nova Bay, Ross Sea during the Italian Antarctic Expedition 1987/1988. Vacchi et al. (1992) described the composition of the coastal fish community. Stomach content analysis was conducted on Trematomus bernacchii and T. pennellii to evaluate the trophic overlap (Vacchi et al. 1994). During the survey, several specimens of T. newnesi were caught at 92 m depth. This fish is a coastal species widespread in the high-Antarctic Zone and also known from the South Shetland Islands and the South Orkney Islands (DeWitt et al. 1990). Although T. newnesi was found down to 400 m depth (Tiedtke & Kock 1989), it seems more abundant in very shallow inshore waters (Naito & Iwami 1982, Williams 1988). Andriashev (1970) and Williams(1988) stated T. newnesi was a cryopelagic species associated with the underside of the sea-ice. At Signy Island, T. newnesi was described as semipelagic species eating amphipods (Richardson 1975). Eastman & DeVries (1982) consider it to be both a cryopelagic and benthic species in McMurdo Sound. Targett (1981) found that T. newnesi feeds on krill and plankton at the South Orkney Islands. Planktivory has also been indicated at the South Shetland Islands (Casaux et al. 1990).

Theoretical analysis of the weight-length relationship in fish juveniles

The weight-length relationship in fish juveniles was investigated theoretically, to assess the significance of the allometric factor and the validity of the condition factor; these biological factors often remain undetermined, because most fishery studies have been conducted for commercial-sized and/or adult populations. The exponent b (allometric factor) seemed to be the main parameter, performing a key role in the equation W=aL b , where W=weight, a is a constant and L=length. The parameters a (condition factor) and K (ponderal index; K=103W/L3) were judged to be less important in comparative studies, since these parameters were closely correlated with b. It is recommended that the assumed theoretical value of b=3 not be used in applied ichthyological surveys, since this value was rarely obtained in the studies, and since a much wider range is usually seen. These analyses led to a new working hypothesis — not yet verified — which opens a new approach to understanding the biological significance of the allometric factor. This approach involves the fractal theory (where b may be considered as a fractal dimension equivalent) linked to the theory of saltatory ontogeny [where b is a threshold characteristic in the (early) life history of fishes].

A New Subspecies of Tui Chub (Osteichthyes: Cyprinidae) from Guano Basin, Nevada and Oregon

A new subspecies of tui chub, Gila bicolor eurysoma, is described from the Guano Basin of northwestern Nevada and southeastern Oregon. Gila bicolor eurysoma is most closely allied to the undescribed subspecies of tui chub in Catlow Basin, Oregon, which supports the evi- dence for recent connections between waters of the two basins. As part of an ichthyological survey of waters in the Sheldon National Wild- life Refuge in northwestern Nevada during 1978 and 1979, we herein examine the taxonomic status of a tui chub population inhabiting an intermittent stream in the headwaters of the Guano Basin system. This population, along with another tui chub population in the Oregon part of the basin, is herein described as a new subspecies. These populations are relicts isolated when pluvial waters that dominated many valleys in the Great Basin province 10,000 to 30,000 years ago receded (Hubbs et al., 1974).

An ichthyological survey of the Fly River in Papua New Guinea with descriptions of new species

An ichthyological survey of the Fly River in Papua New Guinea with descriptions of new species

Distribución y aspectos ecológicos de los peces de las cuencas hidrográficas de Arenal, Bebedero y Tempisque, Costa Rica

An ichthyological survey was made of the Lake Arenal, Rio Bebedero and Rio Tempisque drainages where respectively, 25, 22 and 21 species of fishes were collected. The study was urgent because a hydroelectric project will soon enlarge Lake Arenal and divert its waters to the Pacific slope for hydroelectric and irrigation purposes.The altitudinal and geographic distribution of these icthyofaunas and pertinent ecologic variables were analysed. The species were classified according to their preferred current velocities, and aspects of temperature, type of substrate and size of river were also treated.Current velocity and size of river appear to be most important in determining the upper altitudinal limits of some fishes. Lower altitudinal limits seem most influenced by water temperature and interspecific competition. Geographic distribution is most influenced by current velocity and the resulting effect on other parameters. Stenotopic species with spotty distributions are probably limited by the availability of suitable habitats. Some lowland species of the Tempisque and Bebedero drainages apparently cannot compete with the relatively divers ichthyofauna of these large drainage basins, but are common in depauperate coastal streams.Two species, Neoheterandria umbratilis and Bryconamericus scleroparius are reported for the first time on the Pacific versant of Central America, and a new species of Rivulus was taken in the Arenal region and Bebedero headwaters. The two former species, as well as many others common to both versants, have reached the Pacific versant by crossing low altitud passes of the continental divide.One collection from Arenal and another from the Tempisque basin, both of relatively high species diversity, come from waters of high biomass, productivity and habitat diversity.We predict that the Arenal ichthyofauna in general will adapt to the new reservoir environment after an initial period of disequilibrium and suggest precaution in considering any future introductions of exotic fish species. The eventual passage of fish from Arenal to the Pacific versant should have no adverse effects.

Notropis saladonis, a New Cyprinid Fish Endemic in the Rio Salado of Northeastern Mexico

HE small minnow described below adds one more element of northern affinity to the predominantly Nearctic fauna of northeastern Mexico. It was discovered during a review of the extensive material that Luciano Val Guerra collected in June 1951, during his fish-faunal survey of the Rio Salado System (Guerra's material, as well as his M.A. thesis, Ichthyological Survey of the Rio Salado, Mexico, is deposited in The University of Texas). Two additional series were subsequently located in collections made by Seth Eugene Meek and by E. G. Marsh, Jr. (deposited, respectively, in the Chicago Natural History Museum and the University of Michigan Museum of Zoology). For the opportunity of studying and reporting on this ichthyological discovery we are grateful to the collectors of the material and to the curators of the mu-

Underwater Behavior of the Southern Sea Lion, Otaria jubata

Until the recent advent of shallow-water diving equipment observations on the underwater behavior of mammals have been difficult and therefore meager. With the use of modern equipment, a colony of Otaria jubata (Gmelin) was observed and photographed underwater during an ichthyological survey in the area of the Galapagos Islands between February 26 and March 4, 1955. Underwater activity of females and young generally followed the playful pattern observed above water. The bull of the rookery was never observed in a frolicking …

The Need for Ichthyological Surveys of the Major Rivers of Western North America

The Need for Ichthyological Surveys of the Major Rivers of Western North America

Results of an ichthyological survey about the San Juan Islands, Washington

Results of an ichthyological survey about the San Juan Islands, Washington