INFORME CIENTÍFICO-TECNOLÓGICO[1]
PERIODO: 2001-2003
Legajo Nº: 267
1.
NOMBRES:.Jorge Rafael
2.
Estudio de la diversidad en las especies de peces de la República Argentina
3.
DATOS RELATIVOS A INGRESO Y PROMOCIONES EN LA CARRERA
INGRESO:
Categoría: Inv. Asistente. Mes: 8. Año: 1987.
ACTUAL:
Categoría: .Inv. idependiente desde el mes:6.Año: 1998.
4.
INSTITUCION DONDE DESARROLLA LA TAREA
Nombre:Universidad
Nacional de La Plata.
Dependencia:
Facultad de Ciencias Naturales y Museo
Dirección.Calle:
Paseo del bosque Nº.s/n.
Ciudad:.La
Plata Pcia:.Bs. As...Tel:.4257744.
Dirección
electrónica:.jrcas@museo.fcnym.unlp.edu.ar
Cargo
que ocupa:Docente-Investigador..
Firma
del Investigador
Fecha.28./.5../.2003
6.
EXPOSICION SINTETICA DE LA LABOR DESARROLLADA EN EL PERIODO. Durante este
período se prosiguió con el desarrollo de los proyectos que se venían
realizando en los períodos anteriores. Estos incluyen estudios en sistemática y
biología de los peces de los Esteros del Iberá, ríos y arroyos de la provincia
de misiones, y estudios en peces fósiles del Mioceno. Los resultados obtenidos
de las tareas realizadas se encuentran listados en los puntos que siguen a
continuación.
7.
TRABAJOS DE INVESTIGACION REALIZADOS O PUBLICADOS EN ESTE PERIODO.
7.1.
PUBLICACIONES.
1. 2003. Los peces de la Laguna Iberá, Editorial Al
Margen, La Plata, 203 pp. (J. Casciotta, A. Almirón y J. Bechara).
7.1.b. Revistas periódicas
2. 2001. A new species of Hypobrycon
(Characiformes: Characidae) from Uruguay basin in Misiones, Argentina. Neotrópica, Argentina, 47: 33-40. (A. Almirón, M.
Azpelicueta y J. Casciotta).
Una nueva especie de Hypobrycon (Characiformes:
Characidae) de la cuenca del río Uruguay, en Misiones, Argentina. El género Hypobrycon
se registra por primera vez en Argentina. Hypobrycon poi,
colectado en la cuenca del río Uruguay, se distingue de H. leptorhynchus
por tener mayor número de escamas perforadas en la línea lateral y de dientes
en el dentario, maxila mas corta y cuerpo mas bajo. Hypobrycon poi
se diferencia de H. maromba por la posición de la boca, maxila
mas corta, cabeza y diámetro orbitario mas largos, y mancha humeral elongada
dorso-ventralmente, en lugar de subcircular. Además, los machos de H. poi
tienen ganchitos en los radios de las aletas anal, dorsal, pectoral y pélvica,
ausentes en H. maromba y H. leptorhynchus.
3. 2001. Vertebral column and associated elements in
dipnoans and comparison with other fishes. Development and homology. Journal of
Morphology, USA, 250:101-172. (Arratia, G., H-P. Schultze y J. Casciotta).
A vertebral column consisting of a persitent notochord
and ossified archocentra is the primitive condition for Gnathostomata; it still
persist in primitive actinopterygians ans srcopterygians. Advanced
actinopterygians and sarcopterygians develop numerous types of centra that
include, among others, the presence of holocentrum, chordacentrum, and
autocentrum. The Chodcentrum, a minerilazation or calcification of the fibrous
sheath of the notochord , is only found in actinopterygians, whereas an
autocentrum is a synapomorphy of teleosts above Leptolepis coryphaenoides. The
chordacentrum, formes by migration of cartilaginous cells from the arches into
the fibrous sheath of the notochord and usually covered by a thin
calcification, is a unique feature of chondrichthyans. The actinopterygian
chordacentrum and the chondrichtyan chordacentrum are not homologous. The
postcaudal cartilaginous centrum is only known in postcaudal vertebrae of
living dipnoans. The holocentrum is present in certain fossil dipnoans and
actinopterygians, where it has been independenly acquired. It is formed by proliferation
of cartilage cells around the elastica externa of the notochord. The cells
later ossify, forming a compact centrum. A vertebral column formed by a
persistent notochord without vertebral centra is the primitive pattern for all
vertebrata . The formation of centra , which is not homologous among vertebrate
groups, is acquired independently in some linages of placoderms, most advenced
actinopterygians, and some dipnoans and rhipidistians. Several series of
structures are associated with the vertebral column such as supraneurls,
interhaemals, radials, and ribs. In living dipnoans median neural spine,
‘supraneural’, and dorsal radial result from growth and distal differentiation
of one median cartilage into two or three median bones during ontogeny. The median
neural spine articulates with the neural arch and fuses with it in the caudal
vertebrae early in ontogeny. Two bones differentiate in the anterior abdominal
vertebrae, i.e., the proximal neural neural spine and the distal ‘supraneural.’
Three bone sdifferentiate in fron of the dorsal fin, i.e., the proximal neural
spine, the middle ‘supraneural,’ and the distal radial; the same pattern is
observed in font of the anal fin (the proximal haemal spine, the middle
interhaemal, and the distal radial). Considering that the three dorsal (and
also the three ventral)bones originate from growth only one cartilage, they
cannotbe serial homologs of the neural spines, or ‘supraneural’. They are
linear homologs of the median neural cartilage in living dipnoans. The development
of these elements differs within osteichthyans from sarcopterygians to
actinopterygians, in which the neural spine originates as a continuation of the
basidorsal arcualiaand in which the supraneural and radial originate from
independent cartilages that appear al different times during early ontogeny.
The ribs of living dipnoans are unique in that they are not articulated with
parapophyses, like in primitive fossil dipnoans, but a remant of the ventral
arcuale surrounded by a small arcocentrum remains at its base. A true caudal
fin is absent in living dipnoans. The postcaudal cartilages extend to the
caudal tip of the body separating dorsal and ventral rays (or the
camptotrichia). Actinotrichia are present in young dipnoans. They are also
known in extant actinistians and actinopterygians. They probably represent the
primitive state for teleostomes. In contrst, the camptotrichia are unique for
extant dipnoans (and probably Carboniferous nd younger dipnoans). Lepidotrichia
aparently developed many times among
osteichthyans.
4. 2002. Bryconamericus uporas
(Characiformes, Characidae) a new species from the río Uruguay basin, in
Argentina. Revue suisse de Zoologie, Suiza, 109(1):155-165. (J.
Casciotta, A. Almirón y M. Azpelicueta).
Bryconamericus uporas (Characiformes, Characidae) a new species from the río
Uruguay basin in Argentina. - A new species of the genus Bryconamericus
is described from río Uruguay basin in Misiones, Argentina. Bryconamericus
uporas is distinguished by the following combination of characters: low
body (28.9-32.2 in % of SL); premaxillary and maxillary teeth broadest
distally, with seven cusps. Also, the new species has 18-20 branched anal-fin
rays, large subcircular black humeral spot, wide lateral band; light violet
upper half of flank, and lower half silvery.
5. 2002. Two new species of Astyanax from the Paraná basin. Revue
suisse de Zoologie, Suiza,109 (2): 1-17. (M. Azpelicueta, J. Casciotta y A.
Almirón).
Astyanax leonidas a new species from the río Paraná basin in the
northeastern of Argentina (Characiformes: Characidae). – Astyanax leonidas
is described from the headwaters of the arroyo Urugua-í, a tributary of the río
Paraná in the North-East of Argentina. The new taxon differs from the other
species of Astyanax by the presence in males of small hooks on
caudal-fin rays, one maxillary tooth with 3 or 4 cusps; 35 to 37 perforated
scales in lateral line, and 17 to 21 branched anal-fin rays. Astyanax leonidas
is similar to A. ojiara in having hooks on caudal-fin rays in
males, however they are different in the number of cusps of maxillary tooth,
interorbital width, anal-fin base and snout lengths, and body depth.
6. 2002. The southernmost record of Engraulisoma taeniatum
(Characiformes:Characidae) in freshwaters of Argentina. Biogeographica,
Francia, 78 (2): 77-80. (Casciotta, J; A. Almirón; J. Bechara y A.
Gónzalez).
Engraulisoma taeniatum is known from the type locality,
Rio Cuiaba, Mato Grosso, Brasil, Peruvian Amazon and Venezuela. One specimen of
this species was collected from the río Corriente, río Paraná basin and
represents the first record of the species in Argentina. This locality
corresponds to the southermost range of the geographical distribution of E.
taeniatum.
7. 2002. Astyanax paris, a new species from the río Uruguay basin, of
Argentina (Characiformes, Characidae). Copeia, USA, 2002, 4: 1052-1056. (M. Azpelicueta, Adriana E. Almirón, y
Jorge R. Casciotta )
A new species of the characid genus Astyanax is
described. The species is currently known only from two localities in headwater
streams of arroyo Yabotí-Guazú, a tributary of the upper río Uruguay, in
Argentina. Astyanax paris n. sp. can be easily distinguished from
all congeneres by the combination of relatively shallow body (34.9-39.4 % SL),
three or four maxillary teeth, fifth tooth of the inner premaxillary series
posterior to main series, first humeral spot followed by a second one
vertically elongated, sometimes wider than the first, a caudal spot continued
onto the middle caudal-fin rays, large dark chromatophores on the cheek, 34-36
perforated scales in the lateral series and, iv-v, 20-22 anal-fin rays.
8. 2002. Astyanax ita, a
new species from the río Iguazú basin, in Argentina (Characiformes,
Characidae). Zoologische Abhandlungen, 52: 3-10. (A.
Almirón, María de las M. Azpelicueta y J. Casciotta).
Astyanax ita,
only known from arroyo Tateto, is described in the present paper. This stream
is headwater of arroyo Deseado, which flows into río San Antonio, Iguazú basin,
in Argentina. Astyanax ita sp. n. may be distinguished from all
congeneres by the combination of one heptacuspidate maxillary tooth, teeth of
the inner premaxillary series very expanded distally with 7-9 cusps, large eye
(38.6-42.0 in % of HL), relatively shallow body (34.3-39.8% of SL), only one
well developed vertically elongated humeral spot, 34-36 perforated scales in
the lateral series, and iii-iv, 20-24 anal-fin rays.
7.2.
TRABAJOS EN PRENSA Y/O ACEPTADOS PARA SU PUBLICACIÓN.
1. Phenacogaster xx (Eigenmann, 1911)
un nuevo intregrante de la ictiofauna continental Argentina. Casciotta, J; A.
Almirón; J. Bechara; S. Sanchez. En prensa en la Revista de Ictiología
El género Phenacogaster posee una amplia distribución
geográfica en Sudamérica que incluye los ríos Potaro y Tocantins, cuencas de
los ríos Amazonas, San Francisco, Orinoco y Paraguay y ríos costeros del norte
de Brasil. En este trabajo se cita por primera vez Phenacogaster xx
para la cuenca del río Paraná en Argentina.
2. Astyanax xx sp. n. (Characiformes, Characidae) from the
Esteros del Iberá wetland, Argentina (Jorge R. Casciotta, Adriana E. Almirón,
José A. Bechara, Juán P. Roux
& Federico Ruiz Diaz) En prensa en la Revue
suisse de Zoologie, Suiza
Astyanax xx is
described from the Esteros del Iberá, one of the major wetlands in South
America. Astyanax xx bears hooks on all fin rays of males, such
as in A. troya and A. ojiara. Astyanax xx
is distinguished from the remaining species of the genus by the following
combination of characters: one maxillary tooth with 5 or 7 cusps; teeth of
inner premaxillary row expanded distally; low dentary, bearing 8 teeth
decreasing in size anteroposteriorly; 34-37 perforated scales in lateral
series; 6-7 upper transverse scales; iii-v, 21-26 anal-fin rays; orbital
diameter (36.7-43.5 % of HL); postorbital length (37.0-44.7 % of HL); and
peduncle length (32.3-37.7 % of HL). One humeral spot vertically elongated,
bounded by a light area, and a second lateral spot faint or well developed.
3. A new species of Astyanax
from río Uruguay basin, in Argentina (Characiformes: Characidae). (Jorge R. Casciotta, Adriana E. Almirón and María de las
Mercedes Azpelicueta). En prensa en Ichthyological Exploratorations of Freshwaters
The description of a new characid of the genus Astyanax,
restricted to the río Uruguay basin, is presented. Astyanax xx
can be distinguished by the following characters: two or three maxillary teeth,
third or fourth tooth of outer premaxillary series inserted posteriorly to the
rest, large eye (41.1-45.5 in % of HL), first anal-fin ray inserted anterior to
last dorsal-fin ray, high number of anal-fin rays (iv-vi, 25-29), and 37-39
perforated scales in lateral series.The large eye and the presence of 25-29
branched anal-fin rays differentiate the species from other Astyanax
living in southern South America.
4. Bryconamericus sp. n. (Characiformes,
Characidae), a new species from the río Iguazú basin, in Argentina. (María de las Mercedes Azpelicueta,
Jorge Rafael Casciotta &
Adriana Edith Almirón). En prensa
en Revue suisse de Zoologie,
Suiza.
A new species of the genus Bryconamericus is
described from río Iguazú basin in Misiones, Argentina. Bryconamericus xx
is distinguished from all other species by the following combination of
characters: low body depth (28.0-34.5 in % of SL); premaxillary teeth of the
inner series with 3 to 5 cusps; aligned 3 premaxillary teeth of the outer row
tricuspidate, and 3-5 maxillary teeth with 1 to 3 cusps. Also, the new species
has 18-20 branched anal-fin rays, very large black subcircular humeral spot,
wide black lateral band, and 37-39 perforated scales on the lateral line. The
new species was collected in the arroyo Tateto, headwaters of the río San
Antonio, Iguazú basin.
5. Comunidades de peces y gradientes ambientales en los
Esteros del Iberá.
J.A. Bechara, J. Casciotta, A. Almirón,
F. Ruiz Díaz, J. Ortiz y A. González. En prensa como capítulo de un libro
editado por la Universidad Nacional del Nordeste.
6.
La Ictiofauna de los Esteros del Iberá y su importancia en la
designación de la reserva como sitio ramsar.
A.Almirón, J. Casciotta, J. Bechara, P. Roux, S. Sanchez y P. Toccalino.
En prensa como capítulo de un libro editado por la
Universidad Nacional del Nordeste.
11. DIRECCION DE BECARIOS Y/O INVESTIGADORES.
Dra. Adriana E. Almirón, Docente-Investigador,
Facultad de ciencias Naturales y Museo, UNLP. Tema: Estudio sistemático y
biológico en peces del sistema Iberá, 20001-continúa
15. SUBSIDIOS RECIBIDOS EN EL PERIODO.
1. National Geographic Society, Proyecto: Fish
diversity in Esteros del Iberá wetlands, Subtropical Argentina. Director:
J. R. Casciotta. U$S10.000.
2. Fondo
Humedales para el Futuro, Proyecto: La ictiofauna de la Laguna iberá y su
importancia en la designación de la reserva como sitio Ramsar. Director:
J. R. Casciotta. Monto: U$S 4000
18.
TAREAS DOCENTES DESARROLLADAS EN EL PERIODO..
Jefe
de Trabajos Prácticos de la Cátedra Zoología Vertebrados, Facultal de Ciencias
Naturales y Museo. Representa el 25% de mi tiempo laboral.
19.
OTROS ELEMENTOS DE JUICIO NO CONTEMPLADOS EN LOS TITULOS ANTERIORES. Bajo este punto se indicará todo lo que se
considere de interés para la evaluación de la tarea cumplida en el período.
10 Miembro
titular de la comisión asesora del registro de aspirantes para cubrir cargos de
ayudante alumno del Curso Introductorio 2001 (diciembre de 2000).
11 Miembro
titular de la comisión asesora para proveer un cargo de Jefe de Trabajos
Prácticos, dedicación simple en la cátedra de Ictiología (Abril, 2001).
12 Miembro
suplente de la comisión asesora para proveer cuatro cargos de Ayudante alumno,
dedicación simple en Zoología General (Junio, 2002).
13 Miembro de
la Comisión ad-hoc del registro de Aspirantes para cubrir un cargo de Ayudante
Diplomado, semidedicación en la División Zoología Vertebrados (agosto, 2002).
14 Arbitraje
de un capítulo del libro Catfishes. Editores: Kapoor, Arratia y Diogo (2002).
15 Arbitraje
de un capítulo del libro Mesozoic Fishes. Editores: Arratia y Tintori (2002).
16 Arbitro de
un Proyecto de Investigación de la National Science Fundation, USA (2003)
10 TITULO Y PLAN DE TRABAJO A
REALIZAR EN EL PROXIMO PERIODO.
En el próximo período copntinuaré con los proyectos
enunciados en el punto 6.