Comparative study of trophic organization of juvenile fish assemblages of three tidal creeks in a tropical semi‐arid estuary

Abstract

A comparison of three tidal creeks assessed the effects of the hydrological regime on trophic organization in juvenile fish assemblages of 21 species in a tropical estuary in north-eastern Brazil. There were seven trophic guilds represented spatially. Zooplanktivore and zoobenthivore guilds dominated the lower estuary, whereas omnivores and detritivores dominated the upper estuary. In the rainy season, the zooplanktivore and omnivore guilds were more common throughout the estuary, but in the dry season, zoobenthivores and piscivores occurred throughout. The trophic organization results show that (1) there was a higher complexity in tidal creeks in the upper estuary compared with the first tidal creek in the lower region and (2) trophic linkages increased in the upper estuary, principally the number of omnivore and detritivore species. Spatial variation in trophic structure was primarily associated with differences in the location of the tidal creeks along the estuary, and this variability was partly attributed to fish species richness; the number of species increased towards the upper estuary, and additional species occupied different trophic levels or used additional resources.

Trade‐offs between ontogenetic changes and food consumption in Brazilian silverside Atherinella brasiliensis from two tropical estuaries

“…This arrangement provides ideal niches for many fish species, influencing the assemblages' composition along the estuarine gradient (Contente et al ., 2010a; Guinder et al ., 2010; Yeager & Hovel, 2017). In these coastal ecosystems, there is a large amount of essential resources for refuge and feeding, and for such characteristics estuaries can be considered as important nursery areas (Figueiredo & Pessanha, 2015; Tietze & Gerald, 2016). In the tropical zone, most estuaries are positive estuaries because numerous rivers discharge fresh water loads into the sea, leading to a lower salinity in this system; however, some estuaries from the tropical zone are hypersaline, and salinity increases with the distance from the estuary mouth (Potter et al ., 2010; Silva et al ., 2016).…”

Intertidal fishes of Mauritius with special reference to shallow tidepools

“…It is well known that a large number of intertidal fishes stay in intertidal habitats only temporarily, most of which use the shelter in these narrow and more or less isolated habitats as juveniles, but move to deeper water once they reach the adult stage. This can be observed in mangrove areas (Nagelkerken et al 2000, Laegdsgaard and Johnson 2001, Ikejima et al 2003, Mumby et al 2004, Jaxion-Harm et al 2012) and estuaries (Miller et al 1985, Able 2005, Vasconcelos et al 2008, Figueiredo and Pessanha 2016), in which vegetated habitats within estuaries tend to harbour higher densities of many fish species than unvegetated substrates (Sogard 1992).…”

Intraspecific food resource partitioning in Brazilian silverside Atherinella brasiliensis (Atheriniformes: Atherinopsidae) in a tropical estuary, Brazil

“…In creeks, zooplankton represented the main diet item but it was consumed less in Tidal Creek 2, followed by insect and Polychaeta, whereas in Mudflat the principal prey item was Gastropoda. According to Figueiredo, Pessanha (2016), the nature of available prey which inhabits these habitats in this estuary depends on the environmental characteristics, such as substrate and salinity gradient. Therefore, our findings reinforce that spatial heterogeneity is an important factor that influence fish feeding habits.…”

“…Therefore, our findings reinforce that spatial heterogeneity is an important factor that influence fish feeding habits. With regards to the macrofauna and zooplankton in Mamanguape estuary, some studies have shown a distribution pattern at different spatial scales (Nobrega-Silva et al, 2016;Moura et al, 2016;Linden et al, 2017), which has an important role in this food web (Campos et al, 2015;Claudino et al, 2015;Figueiredo, Pessanha 2016).…”

“…The Brazilian Silverside, Atherinella brasiliensis (Quoy & Gaimard, 1854), is a common estuarine resident and generalist species and is abundant in estuaries (Neves et al, 2006;Alves et al, 2016) and others nearshore shallow water ecosystems, as such beaches (Chagas, Junior, 2013;Lacerda et al, 2014;Favero, Dias, 2015), coastal lagoons (Andreata, 2012) and bays (Paiva Filho, Gianinni, 1990;Pessanha, Araújo, 2001;Carvalho, Spach, 2015). Furthermore, A. brasiliensis, show its important in a key structuring role in estuarine food webs (Campos et al, 2015;Figueiredo, Pessanha, 2016), because generalist species are able to feeding and exploit quantitatively on prey from multiple basal nutrient sources (Claudino et al, 2015). Generally, zooplankton, insects, diatoms form the principal diet of Brazilian silversides in estuaries (Contente et al, 2011;Alves et al, 2016).…”