New ghost knifefish
A new species of ghost knifefish has been found in Venezuela.
The new fish, which has been named Sternarchorhynchus gnomus, has recently been described by Donald Taphorn and Carlos de Santana in the journal Ichthyological Exploration of Freshwaters.
The species is the smallest known member of the Sternarchorhynchus genus and was discovered in Venezuela's lower Rio Caroni drainage.
Taphorn and de Santana say that the new knifefish can be told apart from other Sternarchorhynchus using the following unique combination of characters:
"It is diagnosed from congeners on the basis of body coloration, meristic and morphometric characters, such as color pattern of pectoral and anal fi ns, number of scales above lateral line at mid-body, and relative body proportions."
The genus Sternarchorhynchus was erected in 1855 by Castelnau and currently contains six other species: S. britskii, S. curvirostris, S. mesensis, S. mormyrus, S. oxyrhynchus and S. roseni.
For more information see the paper: de Santana CD and DC Taphorn (2006) - Sternarchorhynchus gnomus, a new species of electric knifefish
from the Lower Rio Caroni, Venezuela (Gymnotiformes: Apteronotidae). Ichthyological Exploration of Freshwaters, Vol. 17, No. 1, pp. 1-8, 4 fi gs., 2 tabs., March 2006.
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Three electric knifefishes described
Scientists have found three new species of electric knifefishes living in the Amazon in Brazil.
The new species are all members of the gymnotiform sternopygid genus Rhabdolichops and were caught in the lowland central Amazon region. The group are commonly referred to as glass knifefishes.
Sandra Correa, William Crampton and James Albert described the new species in Copeia, the journal of the American Society of Ichthyologists and Herpetologists, and have named them Rhabdolichops nigrimans, R. navalha and R. lundbergi.
Rhabdolichops nigrimans and R. navalha are currently known only from the very soft and acidic blackwater river systems, while lundbergi lives in the slightly less hostile whitewaters of the main river channels and floodplain channels.
According to the paper, R. nigrimans and R. lundbergi are closely related sister species that sit within a clade that is separate from other Rhabdolichops species. Their grouping is believed to be between Eigenmannia and Rhabdolichops.
Like many members of the Gymnotiformes, some striking sexual dimorphism is seen in some members, with males of R. nigrimans bearing significantly longer caudal fins than females.
The other blackwater species, R. navalha, is believed to be a sister species to R. stewarti. This knifefish also has a unique type of electric organ among the Gymnotiformes:
"Rhabdolichops navalha exhibits a unique morphology of the electric organ where the posterior margin ends abruptly and is replaced posteriorly by rigid and transparent non-electrogenic tissue."
The members of the Rhabdolichops genus typically reach a size of around 30cm/12" and predominantly live in the deep water channels of rivers in the Amazon and Orinoco basin, where they feed upon aquatic invertebrates, such as copepods.
The deeper waters of the river channels are poorly studied, compared to the shallow waters, and contain many species of endemic fishes. It is widely believed that many new species of deepwater fishes remain undescribed in this unusual habitat.
The Rhabdolichops genus currently contains another eight species including: R. caviceps, R. eastwardi, R. electrogrammus, R. jegui, R. troscheli, R. zareti and R. longicaudatus.
For more information see the paper: Correa SB, Crampton WGR and JS Albert (2006) - Three New Species of the Neotropical Electric Fish Rhabdolichops (Gymnotiformes: Sternopygidae) from the Central Amazon, with a New Diagnosis of the Genus. Copeia: Vol. 2006, No. 1, pp. 2742.
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New knifefishes found in Amazon
Two new species of knifefish have been found in the Amazon basin in Brazil.
The two fishes, which are members of the Ghost knifefish family Apteronotidae, have been placed in the genus Sternarchorhynchus and were discovered in Roraima state in Brazil.
Carlos de Santana and Adilia Nogueira, who described the new species in the journal Ichthyological Exploration of Freshwaters, named the species as Sternarchorhynchus severii and Sternarchorhynchus caboclo.
Both of the new Ghost knifefishes were caught near waterfalls and rapids on at Cachoeira on the Rio Mucajai, which flows into the Rio Amazonas.
The two species can be told apart from the other Sternarchorhynchus by both colouration and morphomeristic features.
Nogueira and de Santana wrote in their paper: "Sternarchorhynchus severii new species, is diagnosed from all congeners on the basis of body coloration, meristics and morphological characters such as white or yellow pigments along head and mid-dorsum forming long pale stripe, number of total anal-fin rays, and body proportion.
"Sternarchorhynchus caboclo, new species, is distinguished from the other species by the hyoid arch with four branchiostegal rays and the posttemporal not fused with the supracleithrum."
There are currently six others in the genus: S. britskii, S. curvirostris, S. mesensis, S. mormyrus, S. oxyrhynchus, and S. roseni.
For more details on the new species see the paper: de Santana CD and Adilia N (2006) - Two new species of Sternarchorhynchus Castelnau from the Amazon Basin, Brazil (Gymnotiformes: Apteronotidae). Ichthyol. Explor. Freshwaters, Vol. 17, No. 1, pp. 85-92, 4 fi gs., 1 tab., March 2006.
A new species of ghost knifefish has been found in Venezuela.
The new fish, which has been named Sternarchorhynchus gnomus, has recently been described by Donald Taphorn and Carlos de Santana in the journal Ichthyological Exploration of Freshwaters.
The species is the smallest known member of the Sternarchorhynchus genus and was discovered in Venezuela's lower Rio Caroni drainage.
Taphorn and de Santana say that the new knifefish can be told apart from other Sternarchorhynchus using the following unique combination of characters:
"It is diagnosed from congeners on the basis of body coloration, meristic and morphometric characters, such as color pattern of pectoral and anal fi ns, number of scales above lateral line at mid-body, and relative body proportions."
The genus Sternarchorhynchus was erected in 1855 by Castelnau and currently contains six other species: S. britskii, S. curvirostris, S. mesensis, S. mormyrus, S. oxyrhynchus and S. roseni.
For more information see the paper: de Santana CD and DC Taphorn (2006) - Sternarchorhynchus gnomus, a new species of electric knifefish
from the Lower Rio Caroni, Venezuela (Gymnotiformes: Apteronotidae). Ichthyological Exploration of Freshwaters, Vol. 17, No. 1, pp. 1-8, 4 fi gs., 2 tabs., March 2006.
-----------------------------------------------------------------------------------------------------------
Three electric knifefishes described
Scientists have found three new species of electric knifefishes living in the Amazon in Brazil.
The new species are all members of the gymnotiform sternopygid genus Rhabdolichops and were caught in the lowland central Amazon region. The group are commonly referred to as glass knifefishes.
Sandra Correa, William Crampton and James Albert described the new species in Copeia, the journal of the American Society of Ichthyologists and Herpetologists, and have named them Rhabdolichops nigrimans, R. navalha and R. lundbergi.
Rhabdolichops nigrimans and R. navalha are currently known only from the very soft and acidic blackwater river systems, while lundbergi lives in the slightly less hostile whitewaters of the main river channels and floodplain channels.
According to the paper, R. nigrimans and R. lundbergi are closely related sister species that sit within a clade that is separate from other Rhabdolichops species. Their grouping is believed to be between Eigenmannia and Rhabdolichops.
Like many members of the Gymnotiformes, some striking sexual dimorphism is seen in some members, with males of R. nigrimans bearing significantly longer caudal fins than females.
The other blackwater species, R. navalha, is believed to be a sister species to R. stewarti. This knifefish also has a unique type of electric organ among the Gymnotiformes:
"Rhabdolichops navalha exhibits a unique morphology of the electric organ where the posterior margin ends abruptly and is replaced posteriorly by rigid and transparent non-electrogenic tissue."
The members of the Rhabdolichops genus typically reach a size of around 30cm/12" and predominantly live in the deep water channels of rivers in the Amazon and Orinoco basin, where they feed upon aquatic invertebrates, such as copepods.
The deeper waters of the river channels are poorly studied, compared to the shallow waters, and contain many species of endemic fishes. It is widely believed that many new species of deepwater fishes remain undescribed in this unusual habitat.
The Rhabdolichops genus currently contains another eight species including: R. caviceps, R. eastwardi, R. electrogrammus, R. jegui, R. troscheli, R. zareti and R. longicaudatus.
For more information see the paper: Correa SB, Crampton WGR and JS Albert (2006) - Three New Species of the Neotropical Electric Fish Rhabdolichops (Gymnotiformes: Sternopygidae) from the Central Amazon, with a New Diagnosis of the Genus. Copeia: Vol. 2006, No. 1, pp. 2742.
-----------------------------------------------------------------------------------------------------------
New knifefishes found in Amazon
Two new species of knifefish have been found in the Amazon basin in Brazil.
The two fishes, which are members of the Ghost knifefish family Apteronotidae, have been placed in the genus Sternarchorhynchus and were discovered in Roraima state in Brazil.
Carlos de Santana and Adilia Nogueira, who described the new species in the journal Ichthyological Exploration of Freshwaters, named the species as Sternarchorhynchus severii and Sternarchorhynchus caboclo.
Both of the new Ghost knifefishes were caught near waterfalls and rapids on at Cachoeira on the Rio Mucajai, which flows into the Rio Amazonas.
The two species can be told apart from the other Sternarchorhynchus by both colouration and morphomeristic features.
Nogueira and de Santana wrote in their paper: "Sternarchorhynchus severii new species, is diagnosed from all congeners on the basis of body coloration, meristics and morphological characters such as white or yellow pigments along head and mid-dorsum forming long pale stripe, number of total anal-fin rays, and body proportion.
"Sternarchorhynchus caboclo, new species, is distinguished from the other species by the hyoid arch with four branchiostegal rays and the posttemporal not fused with the supracleithrum."
There are currently six others in the genus: S. britskii, S. curvirostris, S. mesensis, S. mormyrus, S. oxyrhynchus, and S. roseni.
For more details on the new species see the paper: de Santana CD and Adilia N (2006) - Two new species of Sternarchorhynchus Castelnau from the Amazon Basin, Brazil (Gymnotiformes: Apteronotidae). Ichthyol. Explor. Freshwaters, Vol. 17, No. 1, pp. 85-92, 4 fi gs., 1 tab., March 2006.
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