Boletín de la Sociedad Zoológica del Uruguay, 2023
Vol. 32 (1): e32.1.3
ISSN 2393-6940
This is the first record of the rare calanoid copepod
Odontodiaptomus thomseni for Brazil since this species
was described by Brehm (1933) from Uruguay. There
were found 11 individuals in four sampling sites. This
record extends beyond Uruguay River Basin and La Plata
River Basin the distribution of this species.
Keywords: Zooplankton, few records, rare.
Primer registro de Odontodiaptomus thomseni
Brehm (1933) (Copepoda, Calanoida) en el estado de
Rio Grande do Sul, Brasil. Este es el primer registro del
raro O. thomseni para Brasil desde que esta especie fue
descrita por Brehm (1933) de Uruguay. Este registro se
extiende más allá de la cuenca del río Uruguay y la cuenca
del río La Plata la distribución de esta especie.
Palabras clave: Zooplancton, pocos registros, rara.
The lack of records of freshwater copepod
Odontodiaptomus thomseni led to its inclusion in the
Red List of threatened species (IUCN) category of
data deficient (IUCN, 2022). The first and valid record
for O. thomseni is that of its original description by
Brehm (1933) from Uruguay. Samples taken in 2010
allowed to produce the second record for O.thomseni
in Salto Grande reservoir, which is located in the lower
stretch of the Uruguay River, between Uruguay and
Argentina, within at the La Plata River Basin
(Perbiche-Neves et al, 2012). In this occasion, the
author´s found just three specimens (two males and
one female).
This note presents the first record of O. thomseni
in Guaíba Lake (29º55' to 30º37' S and 50° 56' to 51°
46' W), Rio Grande do Sul state, Brazil, handing an
updated scenario of its geographic distribution
besides the Uruguay River Basin. Also, is the third
official record since its description by Brehm (1933),
confirming its rarity but not too restricted geographic
distribution. The Guaíba Lake is formed mainly by the
rivers Jacuí, Caí, Sinos and Gravataí, which together
drain the second major area of the state, back just to
Uruguay river basin. The Lake has an area of 2,459.91
km², covering the total or partial areas of 14
municipalities, and with an estimated human
population for the basin whith approximately
1,285,614 inhabitants, with a density of 523
inhabitants / km .
Plankton samples were collected on August in
2018, from four sites: site 1 (29°57'46.6"S and
51°20'45.1"W), site 2 (9°58'32.4"S and 51°15'20.1"W),
site 3 (30°00'46.6"S and 51°13'07.5"W), and site 4
(29°56'34.5"S and 51°16'03.7"W) (Fig. 1). The
organisms were collected by vertical and horizontal
hauls with samplings undertaken on each sampling
occasion to form a 300 L composite sample. The
samples were filtered through a zooplankton net (68
μm) and preserved in 4% formalin.
Bol. Soc. Zool. Uruguay (2ª época). 2023. ISSN 2393-6940Vol. 32 (1): e32.1.3
FIRST RECORD OF Odontodiaptomus thomseni Brehm (1933) (COPEPODA,
1* 2 3 4
Jorge Laço Portinho , Raquel Freiry , Gilmar Perbiche-Neves , and Cristina Stenert
1Departamento de Biodiversidade, Universidade Estadual Paulista (UNESP) Rio Claro, 13506-692,
São Paulo, Brasil.
2Limnosul, Rua Teófilo Souto Maior, 152 – centro, Sapucaia do Sul, Rio Grande do Sul, Brasil.
3Laboratório de Plâncton, Departamento de Hidrobiologia, CCBS, Universidade Federal de São Carlos, São
Carlos, São Paulo, Brasil. E-mail:
4Programa de Pós-Graduação em Biologia de Ambientes Aquáticos Continentais, Instituto de Ciências
Biológicas, Universidade Federal do Rio Grande (FURG), Rio Grande, RS, Brasil.
Fecha de recepción: 5 de enero de 2023
Fecha de aceptación: 2 de mayo de 2023
*Corresponding author: