Abstract
ABSTRACT Boeckella poopoensis Marsh, 1906 is one of the most common copepods in the saline lakes of South America, where generally is the species that greater contributes to the zooplankton community biomass. Despite of its wide geographic distribution and ecological importance, the characteristics of the postembryonic stages are unknown, which prevents a detailed understanding of the structure and dynamics of natural populations. The objective of this work was to describe the morphology of the postembryonic stages and to compare it with other species of Centropagidae. The specimens were obtained from a monospecific culture acclimatized in the laboratory. The lineage comes from El Carancho shallow lake (65°03’W, 37°27’S). The identification of the postembryonic stages was performed according to the characteristics established for copepod calanoids. Based in all developing stages, some characteristics that distinguish B. poopoensis from another species of the genus are: lobes of nauplii with the same number of setae of equal length; beginning of body segmentation from nauplii III; sexual dimorphism from copepodite IV (although only evident in the V leg); the endopod of the V leg of copepodites V males and females are biarticulate, but while females endopod add setae respect to the previous stage, males endopod lose them and remain glabrous as in the adults. Copepodites V do not present characteristics typical of adults, such as, the most developed thoracic left wing of females and in the geniculate right antenna of males. All stages of B. poopoensis are larger than those corresponding to other species of centropagids, and in the immature stages, the appendages show their own patterns of setae and have a slightly smaller number of setae than that of the other species of the family.
Highlights
Boeckella poopoensis Marsh, 1906 is one of the most common copepods in the saline lakes of South America, where generally is the species that greater contributes to the zooplankton community biomass
Despite of its wide geographic distribution and ecological importance, the characteristics of the postembryonic stages are unknown, which prevents a detailed understanding of the structure and dynamics of natural populations
Given the wide geographical distribution and importance of B. poopoensis and the lack of information regarding the distinctive characteristics of its different larval stages, the aims of the present work were to describe 11 postembryonic stages, to compare them with the other species of Centropagidae, such as the Australian B. opaqua and the estuarine Gladioferens pectinatus (Brady, 1899), and to identify their primary differences
Summary
Boeckella poopoensis Marsh, 1906 is one of the most common copepods in the saline lakes of South America, where generally is the species that greater contributes to the zooplankton community biomass. Descripción de los estadios postembrionarios de Boeckella poopoensis (Crustacea, Copepoda, Centropagidae). En base a todos los estados de desarrollo, algunas de las características que distinguen a B. poopoensis de otras especies del género son: lóbulos de los nauplios con el mismo número de sedas de igual longitud; la segmentación del cuerpo se inicia en el estadio de nauplio III; el dimorfismo sexual empieza a notarse a partir del copepodito IV (aunque sólo es evidente en la pata V); el endopodito de la pata V de los copepoditos V machos y hembras es biarticulado pero, mientras las hembras adquieren sedas con respecto al estadio anterior, los machos las pierden, llegando a ser glabras como en los adultos. The juvenile stage simplification (grouping all the naupliar or copepodite stages together) makes it possible to analyze the copepods population. It does not allow obtaining a detailed understanding of the structure and dynamics of natural. One study was conducted by Fairbridge (1945) on Boeckella opaqua Fairbridge, 1945, a calanoid species from Australia. Chapman & Burns (1976) compared the IV and V copepodite stages from five calanoid species. Czaika (1982) developed keys for naupliar and copepodite instar identification from 12 calanoid (does not include species of Boeckella) and cyclopoid species from the Great Salt Lake of Utah to facilitate their recognition in the stomach content of fish, and Jersabek et al (1996) studied the naupliar development of the calanoid Acanthodiaptomus denticornis (Wierzejski, 1887) and Arctodiaptomus alpinus (Imhof, 1885)
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