Hydrobiologia 298: 253-262, 1995.
D. Belk, H. 1. Dumont & G. Maier (eds), Studies on Large Branchiopod Biology and Aquaculture II.
© 1995 Kluwer Academic Publishers.
253
Review of Colombian Conchostraca (Crustacea) - morphotaxonomic aspects
Ewald W. Roessler
Departamento de Ciencias Biol6gicas, Universidad de los Andes, A.A. 4976, Bogota, Colombia, South America
Key words: Conchostraca, South America, Colombia, morphotaxonomy, neoteny
Abstract
This paper presents an overview of the current knowledge about species diversity and morphological taxonomy
of the Colombian conchostracan fauna. Relationships among morphological variability, reproductive biology and
environmental conditions are stressed. The Colombian fauna includes 12 species in five families: Limnadiidae
Sars, 1896; Leptestheriidae Daday, 1915; Cyclestheriidae G. O. Sars, 1899; Metalimnadiidae Stra~kraba, 1965;
and Lynceidae Stebbing, 1902. No member of the families, Cyzicidae Stebbing, 1910, or Imnadiidae Botnariuc &
Orghidan 1941 have been found in Colombia. Morphology depends on developmental stage and on the modulating
effects of environmental conditions. Extremely high temperatures may lead to specimens with neotenic features in
Eulimnadia magdalenensis Roessler, 1990.
Introduction
Colombia is situated at the northwest corner of South
America and its 1 138338 square kilometers of total
surface area extend approximately from 4 0 S to 12 0
of N latitude.
Of geomorphological and biological interest is the
north, terminal extension of the Andes mountain range,
bordering the Pacific and extending from South to
North. Within Colombia, this range splits into three
minor ranges, known as the Oriental, Central and Occidental Cordillera: these define the main drainage systems and climatic zones of the country. The general climate depends on the annual cycle of the Trade Winds
and the seasonal shifts of the intertropical convergence
zone. The general geography and the geomorphology create a high diversity of climactic conditions. The
high mountain regions are cold and covered with permanent glacial shields. Deep valleys, extensive lowland and floodplains have warm climates, ranging from
arid desert conditions to the typical humid rain forest
environments.
Although the wide range of geomorphological features (in combination with the regime of dry and wet
seasons) is particularly favorable for branchiopods,
species diversity within this crustacean class seems
generally poor. The branchiopods of Colombia are
mainly conchostracans. Notostraca are apparently
absent and, to date, we have found freshwater Anostraca only of the genus Dendrocephalus, in the tropical
lowlands, east of the Oriental Cordillera. In addition,
certain strains of Artemia have been found, along the
Colombian Caribbean Coast.
In this paper I want to give an overview of the
Colombian Conchostracan fauna and to comment on
the variability of selected morphological features generally used in morphological taxonomy. Because I am
summarizing an ongoing research program, the information on conchostracan species diversity in Colombia
must be viewed as incomplete.[-0.8cm]
Materials and methods
Studies have been carried out over the past 15 years,
mostly in the tropical lowlands of Colombia. I have not
yet surveyed certain regions along the Pacific coast,
the deep rain forest regions of the Colombian part of
the Amazon and its tributaries, and the Northeastern
Guajira Peninsula.
Specimens were collected with dip nets and plankton nets with varying mesh widths according to the
developmental stages wanted. Samples were fixed in
4%-8% formalin or 90% ethyl alcohol. For histo-
D. Belk, H. 1. Dumont & G. Maier (eds), Studies on Large Branchiopod Biology and Aquaculture II.
© 1995 Kluwer Academic Publishers.
253
Review of Colombian Conchostraca (Crustacea) - morphotaxonomic aspects
Ewald W. Roessler
Departamento de Ciencias Biol6gicas, Universidad de los Andes, A.A. 4976, Bogota, Colombia, South America
Key words: Conchostraca, South America, Colombia, morphotaxonomy, neoteny
Abstract
This paper presents an overview of the current knowledge about species diversity and morphological taxonomy
of the Colombian conchostracan fauna. Relationships among morphological variability, reproductive biology and
environmental conditions are stressed. The Colombian fauna includes 12 species in five families: Limnadiidae
Sars, 1896; Leptestheriidae Daday, 1915; Cyclestheriidae G. O. Sars, 1899; Metalimnadiidae Stra~kraba, 1965;
and Lynceidae Stebbing, 1902. No member of the families, Cyzicidae Stebbing, 1910, or Imnadiidae Botnariuc &
Orghidan 1941 have been found in Colombia. Morphology depends on developmental stage and on the modulating
effects of environmental conditions. Extremely high temperatures may lead to specimens with neotenic features in
Eulimnadia magdalenensis Roessler, 1990.
Introduction
Colombia is situated at the northwest corner of South
America and its 1 138338 square kilometers of total
surface area extend approximately from 4 0 S to 12 0
of N latitude.
Of geomorphological and biological interest is the
north, terminal extension of the Andes mountain range,
bordering the Pacific and extending from South to
North. Within Colombia, this range splits into three
minor ranges, known as the Oriental, Central and Occidental Cordillera: these define the main drainage systems and climatic zones of the country. The general climate depends on the annual cycle of the Trade Winds
and the seasonal shifts of the intertropical convergence
zone. The general geography and the geomorphology create a high diversity of climactic conditions. The
high mountain regions are cold and covered with permanent glacial shields. Deep valleys, extensive lowland and floodplains have warm climates, ranging from
arid desert conditions to the typical humid rain forest
environments.
Although the wide range of geomorphological features (in combination with the regime of dry and wet
seasons) is particularly favorable for branchiopods,
species diversity within this crustacean class seems
generally poor. The branchiopods of Colombia are
mainly conchostracans. Notostraca are apparently
absent and, to date, we have found freshwater Anostraca only of the genus Dendrocephalus, in the tropical
lowlands, east of the Oriental Cordillera. In addition,
certain strains of Artemia have been found, along the
Colombian Caribbean Coast.
In this paper I want to give an overview of the
Colombian Conchostracan fauna and to comment on
the variability of selected morphological features generally used in morphological taxonomy. Because I am
summarizing an ongoing research program, the information on conchostracan species diversity in Colombia
must be viewed as incomplete.[-0.8cm]
Materials and methods
Studies have been carried out over the past 15 years,
mostly in the tropical lowlands of Colombia. I have not
yet surveyed certain regions along the Pacific coast,
the deep rain forest regions of the Colombian part of
the Amazon and its tributaries, and the Northeastern
Guajira Peninsula.
Specimens were collected with dip nets and plankton nets with varying mesh widths according to the
developmental stages wanted. Samples were fixed in
4%-8% formalin or 90% ethyl alcohol. For histo-