Size-selective dispersal of Daphnia resting eggs by backswimmers ( Notonecta maculata )

Abstract

Freshwater zooplankton is increasingly used to study effects of dispersal on community and metacommunity structure. Yet, it remains unclear how zooplankton disperses. Clearly, birds and wind play a significant role as zooplankton dispersal agents, but they may not always be the main vectors. This experimental study shows that a cosmopolitan aquatic insect, Notonecta , can be an important vector of cladoceran resting eggs (ephippia). Dispersing Notonecta frequently transported ephippia during flight, with a bias towards smaller ephippia in two species. A similar trend was present at the species level: Daphnia species with smaller ephippia were more often dispersed, suggesting that Notonecta could generate specific colonist communities. In addition, buoyancy appeared a critical trait, as non-floating ephippia of Daphnia magna were never dispersed. Our data suggest that Notonecta could be important dispersers of Daphnia , and that knowledge of dispersal dynamics of Notonecta may be used to predict Daphnia dispersal, colonization and resilience to disturbance.

Unintentional dispersal of aquatic invertebrates via footwear and motor vehicles in a Mediterranean wetland area

“…Although dispersal of plant seeds via footwear and cars is relatively well studied (Clifford, 1956;Schmidt, 1989;Londsdale and Lane, 1994;von der Lippe and Kowarik, 2007;Wichmann et al, 2008), this has not been true for aquatic invertebrate propagules. Many other, more 'natural', vectors for aquatic invertebrates have already been put forward, including wind (Vanschoenwinkel et al, 2008a), water connections (Michels et al, 2001;Hulsmans et al, 2007), waterfowl , amphibians (Bohonak and Whiteman, 1999), aquatic insects ( Van de Meutter et al, 2008), crayfish (Moore and Faust, 1972), semi-aquatic mammals (Peck, 1975;A. Waterkeyn, unpublished data) and large terrestrial mammals (Vanschoenwinkel et al, 2008b).…”

“…Besides enabling species to bridge periods of unfavourable environmental conditions, these life stages also dominantly contribute to passive overland dispersal (Panov et al, 2004;Panov and Ca´ceres, 2007). Main natural vectors known to mediate passive dispersal of aquatic invertebrates are waterfowl , wind (Vanschoenwinkel et al, 2008a), amphibians (Bohonak and Whiteman, 1999), aquatic insects ( Van de Meutter et al, 2008), mammals (Vanschoenwinkel et al, 2008b;A. Waterkeyn, unpublished data) and water connections (Michels et al, 2001;Hulsmans et al, 2007).…”

How do freshwater organisms cross the “dry ocean”? A review on passive dispersal and colonization processes with a special focus on temporary ponds

“…Short-distance dispersal can be favoured by several other vertebrates such as cattle, rats, rabbits, amphibians and fish (e.g. Zedler & Black, 1992;Bohonak & Whiteman, 1999;Beladjal et al, 2007;Van Leeuwen et al, 2013 and literature therein) as well as by invertebrates (Duthie, 1929); in particular, crayfish (Pérez-Bote et al, 2005) and flying insects (van de Meutter et al, 2008;Beladjal & Mertens, 2009) are documented vectors for the dispersal of resting stages and seeds among temporary waters, and water mites are known to be phoretic on insect larvae and adults (Di Sabatino et al, 2004;Bohonak et al, 2004).…”

Tropical Amphi-Pacific disjunctions in the Cladocera (Crustacea: Branchiopoda)

“…In fact, ephippia are a main character of the Anomopoda, the largest order within the Cladocera (Fryer, 1987). Cladoceran ephippia contain an embryo in the gastrula stage and the structure can survive unfavourable conditions (periods of drought or cold), can be transported by wind (Cáceres and Soluk, 2002), birds (Proctor, 1964;Figuerola and Green, 2002), mammals (Allen, 2007) and insects (van de Meutter et al, 2008) and form resident egg banks (e.g. Brendonck and De Meester, 2003;Vandeker- et al, 2005a).…”

“…Chydorids are especially adapted to survive in shallow tropical ephemeral systems such as short-lived pools and marshes, where the dormant community holds a significant diversity that can revive, or be hatched, after dessication (Van Damme and Dumont, 2010). The vacuolate, floating ephippia of the Daphniidae lend themselves to long-distance dispersal (van de Meutter et al, 2008), more so than the compact ephippia of the Chydoridae, which are comparably less mobile as a single unit (Fryer, 1972;Frey, 1987). The ephippia of the Chydoridae, the Macrothricidae and the Acantholeberidae are strongly attached to plants and the substrate when shedded (Scourfield, 1902), aimed at forming resident dormant populations and less adapted for long-distance dispersal (Fryer, 1972).…”