The ways in which fish use estuaries: a refinement and expansion of the guild approach

Abstract

each containing multiple guilds. Emphasis has been placed on ensuring that the terminology and 31 definitions of the guilds follow a consistent pattern, on highlighting the characteristics that identify the 32 different guilds belonging to the estuarine category and in clarifying issues related to amphidromy. As 33 the widely-employed term 'estuarine dependent' has frequently been imprecisely used, the proposal 34 that the species found in estuaries can be regarded as either obligate or facultative users of these 35 systems is supported and considered in the guild context. Thus, for example, species in the five guilds 36 comprising the diadromous category and those in the guilds containing species or populations 37 confined to estuaries are obligate users, whereas those in the marine and freshwater estuarine-38 opportunistic guilds are facultative users. 39 40

Age and size compositions, habitats, growth and reproductive characteristics of a terapontid (Pelates octolineatus) in coastal waters

“…Numerous fish species spawn in coastal waters and use, as a nursery area, the sheltered habitats found in inshore waters such as seagrass, surf zones, rocky shores, mangroves and unvegetated soft substrata (Bennett 1989;Harmelin-Vivien et al 1995;Valesini et al 2004), with some of these species also employing those in estuaries for this purpose (Blaber and Blaber 1980;Vasconcelos et al 2008;Woodland et al 2012;Potter et al 2013). Following the completion of their juvenile phase, many of these marine species move into deeper coastal waters, to different habitats, or to both, where they mature and spawn (e.g.…”

Habitat partitioning by juvenile fishes in a temperate estuarine nursery, South Africa

“…These were fixed in 10% formalin for later laboratory identification and measurement. All positively identified fishes were categorized into estuary association categories based on guild according to Potter et al (2015). The categories applicable to this study include, in the marine category, the marine straggler group, the marine estuarine-opportunist group and the marine estuarine-dependent group.…”

“…Estuaries are highly successful nursery areas worldwide in an otherwise competitive environment where refuge and food are premium (Whitfield 1999, Potter et al 2015. Since multiple species co-exist in estuarine nursery areas, this presents clear evidence of successful niche differentiation and some level of successful community co-existence.…”

“…This work examined a well-known estuarine fish nursery in warm temperate South Africa in order to further understand habitat partitioning among juvenile fishes. Early stage marine fishes recruit into estuarine nurseries typically in spring and summer to utilize the mosaic of available habitats in these systems (França et al 2009) during certain life stages (Strydom 2015, Potter et al 2015. Specific habitat preferences within these systems remain an area of interest for fish conservation worldwide (Beck et al 2001, Able 2005, Strydom 2015.…”

The complex early life history of a marine estuarine-opportunist fish species, <em>Solea turbynei</em> (Soleidae) from temperate South Africa

“…The species is a common endemic inhabitant of estuarine and coastal areas ranging from Tanzania, on the east coast of Africa, to the Oliphants Estuary on the Western Cape coast of South Africa Heemstra 1995, MontoyaMaya andStrydom 2009). Solea turbynei is classified as a marine estuarine-opportunist species that usually spawns at sea, with the juveniles occurring in estuaries but also at sea (Whitfield 1998, Potter et al 2013. Adults are known to prefer turbid waters, particularly over muddy substrates in estuaries (Cyrus andBlaber 1987, Richardson et al 2006), where they feed mainly on the siphon tips of the bivalve Solen spp.…”