Steindachneridion

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Steindachneridion
Fossil range: Oligocene - Recent[1]
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Family: Pimelodidae
Genus: Steindachneridion
Eigenmann & Eigenmann, 1919
Species
  • S. amblyurum
    (Eigenmann & Eigenmann, 1888)
  • S. doceanum
    (Eigenmann & Eigenmann, 1889)
  • S. iherengi †
    (Woodward, 1898)
  • S. melanodermatum
    Garavello, 2005
  • S. scriptum
    (Miranda Ribeiro, 1918)
  • S. silvasantosi †
    Figueiredo & Costa-Carvalho, 1999
  • S. parahybae
    (Steindachner, 1877)
  • S. punctatum
    (Miranda Ribeiro, 1918)
Synonyms

Steindachneria
Eigenmann & Eigenmann, 1888

Steindachneridion is a genus of South American Pimelodid catfish (order Siluriformes).

Contents

[edit] Taxonomy

The first species of the genus, S. parahybae, was described in 1877 by Franz Steindachner under the name Platystoma parahybae. Later, Carl H. Eigenmann and Rosa Smith Eigenmann described Steindachneridia, named for Steindachner, for this species and for S. amblyurum (designated as the type species) in 1888. The next year, Eigenmann and Eigenmann described S. doceanum. In 1918, Miranda Ribeiro described S. scriptum and S. scriptum punctatum; later, S. punctatum was studied and considered to be a species of its own. However, because Steindachneria was already being used, these fish were transferred to Steindachneridion in 1919.[1] The most recent species, S. melanodermatum, was described by Garavello in 2005.[1] This genus currently includes six extant species.[1]

There are two fossil species of Steindachneridion. The first fossil species to be described, S. iherengi, was first described to Arius, but subsequently moved to Steindachneridion; though originally considered to be of Pleistocene age, it has later been argued that it is actually of Oligocene age.[1] The second fossil species to be described was S. silvasantosi in 1999.[1]

The phylogenetic placement of Steindachneridion and its relationship to other Pimelodid genera is unresolved.[1] These fish have been classified with Sorubim-like fish such as Brachyplatystoma and Pseudoplatystoma.[1][2] They have also been classified as being more closely related to Phractocephalus and Leiarius.[1]

[edit] Distribution and habitat

Steindachneridion species originate from South America and are restricted to eastern Brazilian coastal drainages, plus the upper Paraná and Uruguay River basin.[1] S. amblyurus originates from the Jequitinhonha River basin.[3] S. doceanum originates from the Doce River basin.[4] S. melanodermatum originates from Iguaçu River in Brazil.[5] S. parahybae originates from Paraíba do Sul and Jequitinhonha River basins.[6] S. punctatum originates from the upper Paraná River and the Uruguay River basins.[7] S. scriptum originates from the Uruguay River.[8]

The large species of Steindachneridion always occur in swift-flowing, clear water rivers running over large stony beds.[1] These fish are naturally scarce in their habitats.[1]

[edit] Appearance and anatomy

Steindachneridion species are large sized fishes, reaching 100 centimetres (40 in) TL or more.[1] S. doceanum reaches 42 cm (17 in) SL.[4] S. melanodermatum reaches a length of about 53.2 cm (21 in) SL.[5] S. punctatum reaches about 70 cm (28 in) SL.[7]

These fish have relatively small eyes and head. They have long maxillary barbels that extend to the base of the dorsal fin or the adipose fin. The adipose fin is relatively long and straight, and its base is longer than the base of the anal fin.[1] Pectoral and dorsal fin spines are short.[1] Most of these species have light grayish or brownish ground color pattern combined with dark brown, vermiculated dark stripes or spots; however, S. doceanum has reticulations over its body instead of spots, and S. melanodermatum is unique in the genus for its dark brown ground color.[1] S. amblyurum differs from other members of this species by having a rounded caudal fin instead of a caudal fin that is notched.[1]

[edit] Relationship to humans

Steindachneridion species suffer intense anthropogenic pressure, through modification to their habitat and due to overfishing; consequently, some of them are highly endangered and practically extinct in various parts of their original areas of distribution. Due to their economic importance as a food source, some aquaculture stations are currently developing programs for captive propagation of Steindachneridion species. Fish produced by these programs would be used in fish farms as well to restore natural stocks in degraded habitats.[2]

[edit] References

  1. ^ a b c d e f g h i j k l m n o p q Garavello, Julio Cesar (2005). "Revision of genus Steindachneridion (Siluriformes: Pimelodidae)" (PDF). Neotropical Ichthyology 3 (4): 607–623. doi:10.1590/S1679-62252005000400018. 
  2. ^ a b Swarça, Ana Claudia; Fenochhio, Alberto Sergio; Cestari, Marta Margarete; Dias, Ana Lúcia (2005). "First chromosome data on Steindachneridion scripta (Pisces, Siluriformes, Pimelodidae) from Brazilian rivers: Giemsa, CBG, G-, and RE banding" (PDF). Genet. Mol. Res. 4 (4): 734–741. 
  3. ^ "Steindachneridion amblyurus". FishBase. Ed. Ranier Froese and Daniel Pauly. May 2007 version. N.p.: FishBase, 2007.
  4. ^ a b "Steindachneridion doceanum". FishBase. Ed. Ranier Froese and Daniel Pauly. May 2007 version. N.p.: FishBase, 2007.
  5. ^ a b "Steindachneridion melanodermatum". FishBase. Ed. Ranier Froese and Daniel Pauly. May 2007 version. N.p.: FishBase, 2007.
  6. ^ "Steindachneridion parahybae". FishBase. Ed. Ranier Froese and Daniel Pauly. May 2007 version. N.p.: FishBase, 2007.
  7. ^ a b "Steindachneridion punctatum". FishBase. Ed. Ranier Froese and Daniel Pauly. May 2007 version. N.p.: FishBase, 2007.
  8. ^ "Steindachneridion scripta". FishBase. Ed. Ranier Froese and Daniel Pauly. May 2007 version. N.p.: FishBase, 2007.