Diferenciação morfométrica e osteológica entre Ramnogaster arcuata (Jenyns) e Platanichthys platana (Regan) (Teleostei, Clupeidae)

Abstract

ABSTRACT. Morphomctric varia tion and osteologica l analysis in Ramllogaster arcuata (Jenyns) a nd Plafanichthys plafalla (Regan) (Teleostei, C lupeidae). Rallll10gasrer arclIara (Jenyns, 1842) and P/aranichrhys p/afana (Regan, 19 17), found ai lhe estuary or Lagoa dos Patos and coastal lagoon (Lagoa Mirim) at the South of Brazil , are two sympatric clupeid fi shes with very similar features. In order to clarify lhe ir taxonomic and geographical ituation , delimiting ilS occurrence in fres h water , a comparati ve stud y of the bony struclures of the head, anal and dorsal fin s and ventral scutes of lhese Iwo sardines was deve loped. The osteological stud y with clear and stain technique included more information about lhe differenti ati on of the group from the bones or lhe supramaxilla. demary, pterygiophore and epipleural ribs. Variat ions on lhe bod y shape of lhose species were analyzed lhrough the multi variate mo rphometry. in order 10 obtain differentialion patterns between the gro ups. Thirty spec ime ns were selec led from each species. The meas urements were oblained by lrllss network , by using 10 homologoll s anat omical landmarks. The analys is of the principal componenl s, adj usted by Burn aby's orthogona l projection, indicated two main group , separated along the PC I. whi ch ex plained 63.2% of the variation between groups. The diagnostic characters that differenliate R. arcuara from P. plarana , were re laled to segments of distance of lhe head , longitudinal growlh, body heighl and caudal pedunde. Furthermo re, two groups o f P. p/afano were found . In spite oflheir morphologica l similarities, lhey presented a differentiation gradient between lhe estuary poplll ati on of the Patos Lagoon and lhe Mirim Lagoon, poss ibly resul ting from lwo eco logica ll y different environments. KEY WORDS . Clupeidae, multi variate morpho metry, morphological varialion , osteology A fa mília Clupeidae é representada por peixes de pequeno porte. São habitantes típicos de regiões costei ras em todos os oceanos, estando presentes também em ambientes estuarinos ou até mesmo em água doce (WH ITEHEAD (9 85).No sistema estuari al da Lagoa dos Patos e nas lagoas costeiras no sul do estado do Ri o Grande do Sul (Fig. I), dois cl upeídeos destacam-se pel a grande semelhança morfológica. Platanichthys plafana (Regan, 1917) é citada para estuá-ri os, ri os e lagoas costei ras, enquanto Ramnogaster arcuata (Jenyns, 1842) está restri ta a águas coste iras e es tuarinas ( WH ITEHEAD 1985) ( Fig. 2A e B).

Reproductive dynamics of Lycengraulis grossidens (Clupeiformes: Engraulidae) and Platanichthys platana (Clupeiformes: Clupeidae) in a subtropical coastal lagoon

“…It is a predatory species that feeds on zooplankton, crustaceans, and especially on small fish (Fischer et al, 2011). P. platana occurs from Brazil to Argentina and is abundant in some coastal lagoons of Brazil (Fialho et al, 2000); it feeds on zooplankton (Campello and Bemvenuti, 2002).…”

Análisis de la morfología ósea de peces de la laguna costera Mar Chiquita, Argentina

“…El sistema óseo constituye el fundamento sobre el cual se apoya la definición de los grandes grupos y la discusión de afinidades y diferencias entre los mismos (Greenwood et al 1966, Monod 1968, Greenwood et al 1973, Nybelin 1973, Rosen 1973, Cervigón 1980. De esta manera, la osteología de peces ha permitido realizar estudios filogenéticos (Pietsch & Zabetian 1990, Collette & Gillis 1992, Chapleau 1993, Hoshino 2001, aportar elementos para la descripción y diferenciación de especies (Kong & Iratchet 1995, Campello & Bemvenuti 2002, Lloris & Matallanas 2003, Díaz de Astarloa 2005, Dyer 2006, Matallanas & Lloris 2006) y elaborar guías de identificación (Newsome 1977, Borodulina 1984, Hansel et al1988Gosztonyi & Kuba 1996, Watt et al1997.…”

The mitochondrial gene COI reveals the origin of the introduction of Platanichthys platana (Regan, 1917) (Clupeiformes, Clupeidae) in a neotropical floodplain

“…For instance, a first supramaxilla was very small or absent, and the number of pelvic-fin rays distinguished it from members of the genus Lile, whereas the presence of posterior fontanels set it apart from the Ramnogaster and other species of Lile. Morphologically, P. platana is characterized by the presence of a silvery lateral band (when alive) and posterior frontal fontanel in adults, a clear temporal foramen, the absence of a lateral line, a superior mouth, tiny or absent supramaxilla, and an elongated body (Cione et al, 1988;Campello & Bemvenuti, 2002;Whitehead, 1985).…”