Sticholonche zanclea (Protozoa, Actinopoda) in fecal pellets of copepods and Euphausia sp. in Brazilian coastal waters

Abstract

Fecal pellets produced by mesozooplanktonic copepods (Centropages velificatus and Paracalanus parvus) and macrozooplanktonic Euphausiacea (Euphausia sp.) were examined using scanning electron microscopy. Fragments of the protozoan Sticholonche zanclea were found in both copepod and in Euphausia sp. fecal pellets, even when the abundance of the protozoan in the water was low. The results suggest that S. zanclea is an important food resource for different trophic levels, including meso- and macrozooplankton, in Brazilian coastal waters.

Diet of the Copepod Calanus Sinicus Brodsky, 1962 (Copepoda, Calanoida, Calanidae) in Northern Coastal Waters of Taiwan During the Northeast Monsoon Period

“…Additionally, non-selective diverse diets are linked to high production among copepods. Consumption of protozoans by copepods was already reported in previous studies (Merrel & Stoeker, 1998;Eskinazi-Sant'Anna, 2006;Fileman et al, 2007). Indeed, some studies showed that copepods ingest microzooplankton preferentially over other microplankton food items (Acartia tonsa Dana, 1849: Kleppel et al, 1991;A.…”

“…According to our results, C. sinicus fed mainly on phytoplankton as was reported by other studies on this species (Uye & Yamamoto, 1995;Uye & Murase, 1997). Dinoflagellates, diatoms, and microzooplankton are reported in copepod diets through examination of gut contents or faecal pellets (Turner, 1984a(Turner, , b, 1986(Turner, , 1991(Turner, , 2002Wu et al, 2004;Eskinazi-Sant'Anna, 2006). Thus, most copepods are considered to be non-selective feeders, given that the components of food residues in the gut are similar to those found in the surrounding environment (Turner, 1991).…”

“…Feeding studies are considered possible methods to characterize the copepod diet. Many previous works on copepod feeding ecology examined faecal pellets using scanning electron microscopy (e.g., Schrader, 1971;Turner, 1977Turner, , 1984aTurner, , b, 1986Turner, , 1991Turner, , 2002Fleddum et al, 2001;Wexels et al, 2003;Schøyen & Kaartvedt, 2004;Wu et al, 2004;Eskinazi-Sant'Anna, 2006;Jansen et al, 2006). However, faecal-pellet analysis methods to determine food preferences have some limitations, since some food remains are unrecognizable after digestion.…”

“…The faecal pellets only contain undigested food items such as diatoms or shells. All food items lacking hard parts or composed only of soft tissue (e.g., flagellates) are digested and cannot be identified from faecal pellets (Bathmann et al, 1987;Eskinazi-Sant'Anna, 2006). On the other hand, some studies directly examined copepod diets by examining gut contents microscopically (Pasternak, 1995;Yang, 1997).…”

Marine zooplankton studies in Brazil: a brief evaluation and perspectives

“…Until recently, ctenophores were only briefly mentioned in few studies on the distribution of estuarine zooplankton (Lopes et al 1986, Montú andCordeiro 1988), although these organisms constitute an important group of pelagic predators in coastal regions (Mills 1995). Oliveira and Migotto (2006) of the São Paulo State coast (Rocha 1983, Lopes and Silveira 1994, Eskinazi-Sant'Anna 2006 and thus there is no information on their meso-or macroscale distribution on the continental shelf and in oceanic areas. Studies done in the Cabo Frio region off Rio de Janeiro State have revealed the numeric importance of ostracods, without however identifying them down to the species level (Valentin 1984(Valentin , 1989.…”