The family Rivulidae is one of the largest families of freshwater fishes of the Neotropical region [1]. It is a diverse group of annual fish, most popularly known as “killifish”, which occurs in seasonal freshwater swamps of tropical and subtropical areas of South America [2]. Brazil has the greatest diversity of the family Rivulidae and is represented by 30 genera with approximately 120 fish s...

Introduced freshwater fishes impact native Hawaiian stream fishes in two important ways. In addition to direct negative effects associated factors such as predation, competition, and interference, indirect effects may occur when exotic fishes transfer their parasites to native hosts. Six species of helminths that have been introduced with alien live-bearing fishes, including guppies, green swor...

During a parasitological investigation on the fresh water fishes of North West of Iran (West Azerbaijan Province), 266 specimens of 11 fishes were examined. Fishes were collected from seven stations from Aras, Zangbar and Sarysou Rivers between summer 2001 to summer 2002. Nine protozoan species were detected; eight Cilliophora and one Rhizopoda. Cilliophora are: Chilodonella sp., Apiosoma sp.,V...

Sanguinicolids, or fish blood flukes, infect the vascular system of both marine and freshwater fishes, and some act as serious pathogens of hosts in aquaculture. Blood flukes typically possess a relatively benign relationship with wild fishes; however, cultured hosts near appropriate intermediate hosts (i.e., snail, bivalve, or polychaete) may accumulate heavy infections of the worms and their ...

Monogenoidea represents a class of hermaphroditic Platyhelminthes ecto-parasitic of mainly fishes. They inhabit the gills, skin, nasal fossae, ureters and some intestinal ducts. Brazil is known as a country with rich fauna, flora and mineral resources, with more than 4000 species of freshwater fishes, representing approximately 31% of the world freshwater fish species. Abou 365 species of Monog...

During a parasitological investigation on the fresh water fishes of North West of Iran (West Azerbaijan Province), 266 specimens of 11 fishes were examined. Fishes were collected from seven stations from Aras, Zangbar and Sarysou Rivers between summer 2001 to summer 2002. Nine protozoan species were detected; eight Cilliophora and one Rhizopoda. Cilliophora are: Chilodonella sp < em>., Apiosoma...

Body size is an important correlate of life history, ecology and distribution of species. Despite this, very little is known about body size evolution in fishes, particularly freshwater fishes of the Neotropics where species and body size diversity are relatively high. Phylogenetic history and body size data were used to explore body size frequency distributions in Neotropical cichlids, a broad...

Surfactants are the major components of detergent used in household as cleaning products. In present study effects of surfactants (Surf excel) on external morphology and physiological respiration (breathing rate) of freshwater fish Labeo rohita have been reported. For this fishes were divided into two groups. Group-I fishes were placed under the concentration of 6.63 mg/lit surfactant and Group...

Although research on parasite biodiversity has intensified recently, there are signs that parasites remain an underestimated component of total biodiversity in many regions of the planet. To identify geographical hotspots of parasite diversity, we performed qualitative and quantitative analyses of the parasite-host associations in fishes from Latin America and the Caribbean, a region that inclu...

The thesis is based on the following articles and manuscripts, which are referred to in the text by their Roman numerals: II Kontula T & Väinölä R (2003) Molecular and morphological analysis of secondary contact zones of Cottus gobio in Fennoscandia: geographical discord-ance of character transitions. Biological Journal of the Linnean Society, in press. III Kontula T & Väinölä R (2003) Comparat...