Results for “pH”

An exceptionally hardy and adaptable species tolerant of a wide range of physiological variables and flexible of diet, factors which have allowed it to become established as an alien species around the globe. Its high reproductive potential and low vulnerability to predation have made it a cause for concern to conservation scientists although as yet there remains no proof of it exerting a negative effect on native fishes in countries outside its natural range.

Known from the middle Mekong basin in Laos and Thailand, including the Mun tributary drainage on the Khorat Plateau in northeastern Thailand, plus the Chao Phraya and Mae Klong watersheds in central and western Thailand, respectively. In the Mekong system it may also occur further upriver in Yunnan province, China, while the Khone Falls in Laos appear to represent its downstream limit.

Inhabits sluggish blackwater tributaries, small rivers and swampy areas, particularly in areas with dense growth of aquatic or overhanging riparian vegetation, submerged woody structures and leaf litter. The water is typically stained darkly with humic acids and other chemicals released by decaying organic material, the dissolved mineral content is generally negligible and pH can be as low as 4.0. N. minimus occurs sympat...

During winter months N. delicata retreats to streams or underflows where it remains dormant between October and April (Kano, 2000) before emerging to spawn. Other species living alongside it in nature include Rhinogobius flumineus, Cottus pollux and Phoxinus spp. Niwaëlla is closely related to Cobitis and N. delicata, also the type species, was described as C. delicata (Niwa, 1937). The combination of characters used to tell it...

Inhabits well-oxygenated, low-to-medium gradient, slow to moderate-flowing rivers and streams with substrates of gravel, cobbles, larger boulders and exposed bedrock. At the habitat in our image pH was 7.5, temperature 26°C and cond...

Type locality is 'Mé-Nam River, Thailand', with 'Mé-Nam' having been considered an older name for the Chao Phraya river in central and western Thailand prior to this species' redescription by Tejavej (2012). In fact 'menam' is the Thai word for 'river' and thus could refer to any drainage, and B. ornatus is restricted to...

This large Tanganyikan species is not seen very often in the hobby. It is often seen in shoals in nature, where it appears to feed primarily on phytoplankton. An adult male would make a truly stunning specimen fish....

The majority of original populations have already been extirpated due to introduction of invasive species such as Gambusia holbrooki and Poecilia reticulata, ongoing deforestation of the Ambohitra Massif, and physical diversion of the source of the Sakaramy River for domestic use by locals. An additional population may exist in a stream on the southern slope of the Ambohitra Massif on the road between Bobasokoa and Anivorano, near the village of Andranotohiliny, but this requires verification.

This species has something of a confused history having been previously been considered synonymous with both A. sophiae (a separate species native to Iraq and Iran) and A. cypris (currently considered a junior synonym of A. mento). Although some populations occur close to and even sympatric with other members of the genus in Turkey phylogenetic studies have shown it to be more closely-related to the Middle Eastern species A. dispar dispar, A. d. richardsoni, A. ginaonis and A. sirhani. It's...

This species was considered to be a phenotype of the similar-looking P. gelius prior to its description. Following Knight (2013) it is included a group of closely-related species alongside P. gelius and P. canius, the trio being distinguished from other members of the genus Pethia by the following combination of characters: lateral line incomplete with 3-4 por...

Little sun is able to penetrate the forest floor so aquatic habitats are shaded and water temperature may be relatively cool, while conductivity and hardness are generally low and pH slightly acid. Macrophytes are uncommon though there may be dense, marginal vegetation, sometimes overhanging the full width of the stream, the roots of which may penetrate the banks underwater. Typical substrates are sandy but covered by a layer of leaf litter with fallen twigs and branches.

There are currently 32 genera and over 80 species included in the family Pimelodidae (including Pimelodus), making it the second largest and one of the most diverse amongst catfish. Most experts agree however, that a full systematic revision of the family is needed, as little information about the phylogenetic (evolutionary relatedness) relationships between the various genera exists. Taxonomy information at the species level is also basic at best. It's therefore likely that at least some o...

There are currently 32 genera included in the family Pimelodidae (including Pimelodus), making it the second largest and one of the most diverse amongst catfish. However most experts agree that a full systematic revision of the family is needed, as little information about the phylogenetic (evolutionary relatedness) relationships between the various genera exists. Taxonomy information at the species level is also basic at best. It's therefore likely that at least some of the Pimelodids will...

There are currently 32 genera and over 80 species included in the family Pimelodidae (including Pimelodus), making it the second largest and one of the most diverse amongst catfish. However most experts agree that a full systematic revision of the family is needed, as little information about the phylogenetic (evolutionary relatedness) relationships between the various genera exists. Taxonomy information at the species level is also basic at best. It's therefore likely that at least some of...

Euryhaline and mostly inhabits coastal floodplains where it's found in both fresh and brackish habitats, including tidal estuaries and salt marshes. It's particularly common in swamps, billabongs, and slow-moving streams where aquatic vegetation grows densely, but some populations have colonised upper sections of freshwater streams. Larger individuals may also move into main river channels. Tappin (2010) gives the following ranges of parameters based on those taken from various localities: temperature 27 - 38 °C, pH 5...

This species is most easily told apart from its only congener P. dayi by lacking (vs. possessing) two dark, irregular lateral stripes on the head and body, and a shorter caudal-fin in males. The results of phylogenetic analyses by Rüber et al. (2006) suggest that Pseudosphromenus is most closely-related to Malpulutta in an evolutionary sense.

The type series was collected from a small clear-water stream with a pH of 6.0, forming a series of riffles and deeper pools, with a maximum width of 5 metres and depth ranging from 10 cm to 1 metre. The substrate was composed of sand gravel and rocks, with some leaf litter and overhanging marginal vegetation.

Recorded from numerous river basins in Vietnam, Cambodia, Laos, Thailand, and Peninsular Malaysia, including the Mekong, Chao Phraya, Mae Khlong, Chanthaburi, Tapi, Golok, Terengganu, Pahang, Endau, and Muar. Type locality is 'Kratt, southeastern Siam', which corresponds to modern-day Trat Province, Thailand.

Rainboth's 'Fishes of the Cambodian Mekong' characterised members of Rasbora by possession of an unbranched, non-spiny firstray and seven soft dorsal rays, origin of thein the middle of the body, five branchedrays, a small mouth not extending below the eye and a lack of barbels. It's long been recognised as a polyphyletic lineage as noted by Kottelat (1999) amongst others, and in 2010 the results of a phylogenetic analysis by T. Y. Liao et al. suggested a number of changes in...

Known from various parts of the middle and upper Mekong river basins with record existing from the Nam Tha, Nam Ou, Nam Khan, Nam Lik, Nam Ngum and Nam Mang tributary systems in Laos, the Nam Noeua (a tributary of Nam Ou) in Vietnam, and the Mae Nam Kok in Thailand. Occurrences in the Chao Phraya drainage in central Thailand most likely refer to the congener R. chiengmaiensis.