Population dynamics of Pseudevadne tergestina (Branchiopoda: Onychopoda) in Guanabara Bay, Brazil

Abstract

Populations of Pseudevadne tergestina were studied in Guanabara Bay, southeastern Brazil, to

Distribution and abundance of Cladocera (Branchiopoda) in the Paraíba do Sul River estuary, Rio de Janeiro, Brazil

“…The species of cladocerans (Table 1) found in the study area are typical of marine and estuarine environments (Coelho-Botelho et al, 1999;Lopes, 1996;Montú, 1980;Nogueira et al, 1999;Valentin & Marazzo, 2003;Marazzo & Valentin 2004), but most are from freshwater environments (Elmoor-Loureiro, 1997;Elmoor-Loureiro et al, 2004;Hann & Zrum, 1997;Montú, 1980;Neves et al, 2003;SantosWisniewski et al, 2002;Sampaio et al, 2002;Serafim Jr. et al, 2003).…”

“…Although it is a marine species, it can penetrate the estuary during the flood tide during periods of low freshwater input. This species is an important component of the zooplankton in coastal and estuarine waters like in the coast off Rio de Janeiro state in certain periods of the year, along with other species such as Pseudoevadne tergestina and Pleopis polyphemoides (Coelho-Botelho et al, 1999;Nogueira et al, 1999;Marazzo & Valentin, 2004), and is an important contributor to secondary production (Marazzo & Valentin, 2004). However, Penilia avirostris may disappear from the plankton at certain periods (Valentin & Marazzo, 2003).…”

“…Temperature controls reproductive rates, species population size and metabolism (Sampaio et al, 2002) all of them the most important factors determining seasonal distribution of marine cladocerans (Marazzo & Valentin, 2004). Other factors such as salinity, dissolved oxygen, tidal currents, can also affect the occurrence and distribution of cladocerans in estuarine environments (Valentin & Marazzo, 2003;Marazzo & Valentin, 2004), salinity being one of the key factors determining the distribution of species of different origin (Montú, 1980). Based on salinity data, it can be concluded that the only species presenting truly estuarine characteristics was Penilia avirostris.…”

“…They are generally seen as a secondary component of the estuarine zooplankton, even though they may compose a significant fraction of the zooplanktonic community. When abundant, they can be an important food item for planktivorous fish and other zooplanktonic predators, and perform a significant role in production of organic matter (Marazzo & Valentin, 2004).…”

Variación diaria de la abundancia del zooplancton en Bahía Magdalena, B.C.S. México

“…Los cladóceros son un grupo en el que predominan las formas de aguas continentales, pero los representantes marinos llegan a constituir una importante fracción de la comunidad zooplanctónica y de la producción de materia orgánica (Marazzo y Valentin, 2004). Las 7 especies marinas conocidas están distribuidas en los géneros: Penilia, Evadne y Podon (Marazzo y Valentin, 2001) especies tuvieron una drástica reducción a pesar de que la temperatura superficial del mar se mantuvo alrededor de 18.4 °C y la concentración de clorofila a aumentó hasta 1.6 mg/m 3 .…”