Hydrobiologia 298: 239-240, 1995.
D. Belk, H. 1. Dumont & G. Maier (eds), Studies on Large Branchiopod Biology and Aquaculture 1I.
© 1995 Kluwer Academic Publishers.
239
Concerning the identity of Branchinecta santacrucensis Cesar, 1987
Rosa Graciela Cohen
Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales. Ciudad Universitaria. Nunez, Pab. II.
Dto. de Biologia. 1428. Buenos Aires. Argentina
Key words: Anostraca, Branchinecta, Taxonomy.
Abstract
The type series of the species Branchinecta santacrucensis Cesar 1987, is compared with specimens of Branchinecta
granulosa Daday 1902 collected near Facundo, Chubut Province, Argentina. The great resemblance between them
suggest that both sets of material belong to the same species and therefore, B. santacrucensis and B. granulosa are
synonyms.
Introduction
Recently, Cohen (1992) redescribed Branchinecta
granulosa Daday 1902, on the basis of adult material from near Facundo (Chubut Province, Argentina).
This was the first step clarifying the identity of this
species.
Cesar (1987) described a new species, Branchinecta santacrucensis, based on specimens from a locality near Coyle (Santa Cruz Province, Argentina);
the same author also assigned to this new species
some specimens collected in other localities of the
same Patagonian Province: on the Fernando Fernandez
Plateau between Viedma Lake and Argentino Lake;
near Lemarchand; near Santa Cruz City; in Gallegos
Norte. Since the type specimens of B. santacrucensis resemble very much those from Facundo identified
by Cohen (1992) as B. granulosa, I present a detailed
comparison of both sets of material.
Material
I examined the holotype (male) and female paratypes of
B. santacrucensis deposited in the Museo Argentino de
Ciencias Naturales de La Plata, Invertebrate Zoology
Section, under the catalogue numbers 20NIII82-No. 4
and 20NIII82-No. 90 (type locality: surroundings of
Coyle, Santa Cruz Province, Argentina), and kindly
sent on loan by Dr. C. Sutton and compaired these
with 23 males and 10 females from a temporary pond
15 km from Facundo, on the road to Colonia Sarmiento
(46 oS, 70 OW), Chubut Province, Argentina.
Results
The holotype of B. santacrucensis and males from the
Facundo population have the following similarities:
- average length ratio of antenna 1 to the basal article
of antenna 2 is 0.6.
- average length ratio of the basal article to the distal
article of antenna 2 is 1.5.
- antenna 2: basal article (Cohen, 1992: Figs 1, 2)
bears on its medial side a proximal spiny tubercle;
proximal half with a medial concave margin; distal
half with a spinelike or blunt process bearing one or
a few small spines (the holotype has a few spines).
This process precedes a prominent widening of the
article to form a crest. The latter is provided with
spines that extend almost to the distal end of the
article and culminates in a mound bearing the most
distal spines. All the spines have a tiny hyaline
projection at the tip. Distal article of both sets of
material have the same appearance; with a trilobate
end and a conspicuous rasp-like area (Cohen, op.
cit.: Fig. 4, 5).
- the appearance of ventral bulges on the genital segments and of the penial apophysis (Cohen, op. cit.:
Fig. 9); the denticles reported by Cesar (1987) on
the penial apophysis were not observed.
The paratypes and females from the Facundo population have the following similarities:
D. Belk, H. 1. Dumont & G. Maier (eds), Studies on Large Branchiopod Biology and Aquaculture 1I.
© 1995 Kluwer Academic Publishers.
239
Concerning the identity of Branchinecta santacrucensis Cesar, 1987
Rosa Graciela Cohen
Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales. Ciudad Universitaria. Nunez, Pab. II.
Dto. de Biologia. 1428. Buenos Aires. Argentina
Key words: Anostraca, Branchinecta, Taxonomy.
Abstract
The type series of the species Branchinecta santacrucensis Cesar 1987, is compared with specimens of Branchinecta
granulosa Daday 1902 collected near Facundo, Chubut Province, Argentina. The great resemblance between them
suggest that both sets of material belong to the same species and therefore, B. santacrucensis and B. granulosa are
synonyms.
Introduction
Recently, Cohen (1992) redescribed Branchinecta
granulosa Daday 1902, on the basis of adult material from near Facundo (Chubut Province, Argentina).
This was the first step clarifying the identity of this
species.
Cesar (1987) described a new species, Branchinecta santacrucensis, based on specimens from a locality near Coyle (Santa Cruz Province, Argentina);
the same author also assigned to this new species
some specimens collected in other localities of the
same Patagonian Province: on the Fernando Fernandez
Plateau between Viedma Lake and Argentino Lake;
near Lemarchand; near Santa Cruz City; in Gallegos
Norte. Since the type specimens of B. santacrucensis resemble very much those from Facundo identified
by Cohen (1992) as B. granulosa, I present a detailed
comparison of both sets of material.
Material
I examined the holotype (male) and female paratypes of
B. santacrucensis deposited in the Museo Argentino de
Ciencias Naturales de La Plata, Invertebrate Zoology
Section, under the catalogue numbers 20NIII82-No. 4
and 20NIII82-No. 90 (type locality: surroundings of
Coyle, Santa Cruz Province, Argentina), and kindly
sent on loan by Dr. C. Sutton and compaired these
with 23 males and 10 females from a temporary pond
15 km from Facundo, on the road to Colonia Sarmiento
(46 oS, 70 OW), Chubut Province, Argentina.
Results
The holotype of B. santacrucensis and males from the
Facundo population have the following similarities:
- average length ratio of antenna 1 to the basal article
of antenna 2 is 0.6.
- average length ratio of the basal article to the distal
article of antenna 2 is 1.5.
- antenna 2: basal article (Cohen, 1992: Figs 1, 2)
bears on its medial side a proximal spiny tubercle;
proximal half with a medial concave margin; distal
half with a spinelike or blunt process bearing one or
a few small spines (the holotype has a few spines).
This process precedes a prominent widening of the
article to form a crest. The latter is provided with
spines that extend almost to the distal end of the
article and culminates in a mound bearing the most
distal spines. All the spines have a tiny hyaline
projection at the tip. Distal article of both sets of
material have the same appearance; with a trilobate
end and a conspicuous rasp-like area (Cohen, op.
cit.: Fig. 4, 5).
- the appearance of ventral bulges on the genital segments and of the penial apophysis (Cohen, op. cit.:
Fig. 9); the denticles reported by Cesar (1987) on
the penial apophysis were not observed.
The paratypes and females from the Facundo population have the following similarities: