Daphnia lumholtzi
System : Terrestrial
Kingdom
Phylum
Class
Order
Family
Animalia
Arthropoda
Branchiopoda
Diplostraca
- General
- Distribution
- Impact
- Management
- Bibliography
- Contact
Common name
water flea (English)
Synonym
Similar species
Summary
Daphnia lumholtzi is a cladoceran commonly referred to as a water flea. It is type of zooplankton that serves as an important food source for larval and juvenile fish. It is invading reservoirs and lakes across North America and it is feared that this species may have a detrimental effect on fish that depend on zooplankton in their larval and juvenile stage. It is also feared that Daphnia lumholtzi will replace native Daphnia and cause a shift in pelagic communities of both zooplankton and fish.
Species Description
The most distinguishing characteristics of D. lumholtzi is its long helmet and tail spines. Its anterior helmet is larger than that produced by any native species, although similar in form.The tailspine is normally at least as long as the body length. Native species have a tail that is much shorter than its overall body length. Other distinct characteristics are the fornices that extend to a sharp point instead of being smooth and rounded like native Daphnia. The ventral carapace margin has approximately 10 prominent spines while native species have weak spinescence (Benson et al. 2004; Harvel and Herbert, 1993).
Notes
Cladocerans, also known as water fleas, are a type of zooplankton that are nearly invisible to the naked eye. Despite their small size, they are an important food source for larval and early juvenile stages of nearly every species of North American fish (Stoeckel and Charlebois, 1999).
Habitat Description
D. lumholtzi is native to tropical and subtropical regions in Africa, Asia, and Australia. It inhabits reservoirs, river oxbows (''billibongs''), and deep tectonic lakes. Most water bodies invaded by D. lumholtzi, reservoirs in the southern regions of the U.S., tend to be more eutrophic than lakes and reservoirs in the north. This species has rapidly invaded a wide variety of habitats, including flood-plain lakes, large rivers and one of the Great Lakes (Havel and Shurin, 2004; Lennon et al. 2003; and Pattinson et al. 2003).
\"D. lumholtzi takes advantage of late summer thermal niches when the water temperature surpasses 25C and will subsequently continue to colonize lakes and reservoirs across North America. It has been shown, though, that D. lumholtzi performs poorly at water temperatures below 10C which may inhibit the range of its expansive into more northern waters\" (Lenon et al. 2001).
Daphnia lumholtzi was reported across 50 kms of the lower Mobile-Tensaw River Delta, Alabama, including a downstream site at the head of Mobile Bay. DeVries et al. (2006) sampled zooplankton during 2002-2005, at six sites in the Mobile-Tensaw River Delta approximatley once a month. D. lumholtzi was found at all six sites. The authors of the study state that \"though salinity was typically at the detection limit of our salinity metre when D. lumholtzi was present, this zooplankton was sometimes also present at elevated salinities\", (salinity in the Mobile-Tensaw River Delta remained near zero throughout the year at all upstream sites but was elevated seasonally at downstream sites). The authors further state that \"This work documents an expansion of the range of D. lumholtzi and also demonstrates that the species can exist in waters that experience periodic pulses of salinity. The ability of D. lumholtzi to survive at low salinity levels beyond what might be found in inland systems (e.g. lake Texoma, Oklahoma-Texas, USA; Work and Gophen 1999) suggests that other coastal environments may be at risk for invasion by D. lumholtzi\" (DeVries et al 2006).
Reproduction
Under stress, daphnids produce resting eggs or ephippia. Ephippia are resistant to adverse environmental conditions and can lay dormant in sediment where they persist for many years delaying hatching until optimal conditions are present. As a result, the absence of D. lumholtzi from a body of water it has previously been found in does not necessarily indicate that it has been extirpated. The ephippia of D. lumholtzi are especially well adapted for dispersal. The ephippia of D. lumholtzi have hairs and spines along the dorsal edge of the egg that could grip boats or other objects and thus aid dispersal (Benson et al. 2004; Dzialowski et al. 2000; Shurin and Havel, 2002).
Pathway
D. lumholtzi can be introduced through fish stocking (Havel and Shurin, 2004).. It is uncertain how D. lumholtzi was introduced into the U.S. It is suspected that it may have been transported with shipments of Nile perch from Lake Victoria in Africa where it is a dominant zooplankter. Nile perch were originally introduced into Texas as early as 1983 (Benson et al. 2004).The continuing discovery of D. lumholtzi in new locations could be due to contaminated stockings of fish through international commercial trade. At the same time, the close proximity of affected reservoirs in Missouri and in Texas might lead to the conclusion that D. lumholtzi may have spread by recreational boating from the initially infested reservoirs (Benson et al. 2004).D. lumholtzi can be transported through construction equipment (Havel and Shurin, 2004).It most likely D. lumholtzi was brought to North America with African fish imported for the aquarium trade or to stock reservoirs (Stoeckel and Charlebois, 1999).
Principal source: Benson et al. 2004. Daphnia lumholtzi
Stoeckel and Charlebois, 1999. Daphnia lumholtzi: The Next Great Lakes Exotic?
Compiler: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)
Review: Andy Dzialowski Postdoctoral Research Associate, Kansas Biological Survey University of Kansas, USA
Publication date: 2006-10-30
Recommended citation: Global Invasive Species Database (2024) Species profile: Daphnia lumholtzi. Downloaded from http://iucngisd.org/gisd/species.php?sc=998 on 29-12-2024.
General Impacts
Benson et al. (2004) report that the impacts of D. lumholtzi are not yet fully understood. Studies have compared native Daphnia to this exotic invader and found that competition between these species is lower than expected. D. lumholtzi population sizes tend to rise in late summer when native Daphnia populations have historically been low allowing D. lumholtzi to fill a vacant \"temporal niche\" in the warmer summer months. If D. lumholzi has a negative impact on other native zooplankton populations in late summer, this may have a detrimental effect on fishes that depend on zooplankton at that time period but are not able to handle the spines of D. lumholtzi since they prevent predation from a number of North American species in the larval and juvenile stages due to gape limitation. In contrast, Leinesch and Gophen (2001) hypothesized that when juvenile fish become large enough to handle D. lumholtzi, the fish can grow more rapidly because D. lumholtzi represent an additional food source during the late summer when native Daphnia are historically rare, reducing and reduce their risk of predation (Benson et al. 2004).\r\n
There are three characterisitcs that have probably led to D. lumholtzi's high invasion potential. 1) Due to its tropical to subtropical native range, D. lumholtzi is adapted to higher temperatures than is native Daphnia. 2) D. lumholtzi is adapted to disturbed areas, giving it an invasion advantage. 3) The long helmet and tail spine helps D. lumholtzi avoid predation .The large spines make it difficult for young fish (larval and juvenile stages) to consume this exotic. The protection from predation afforded by its spines may allow this species to replace native Daphnia. If this replacement occurs, the amount of food available to larval and juvenile fishes may be reduced. However, it may also provide a food source for larger fish that are able to handle its spines because it is present during the late summer when native Daphnia are historically rare. \"The ultimate effects of this invasive species will become more apparent in subsequent years as long-term trends in zooplankton abundance and fish survival and growth within ecosystems invaded by D. lumholtzi are documented\" (Benson et al. 2004; Stoeckel and Charlebois, 1999).
Management Info
It is important to prevent the initial introduction D. lumholtzi to new locations. Because this species has already become established, work needs to be done to slow its spread. Recreational water users can avoid accidentally spreading established exotic nuisance species (and in some cases prevent new introductions) with a few simple steps. Before leaving boat launch: Inspect boat, trailer, and equipment; then remove any observed plants and animals. Drain, on land, all water from the motor, live well, bilge, and transom well. Empty water from bait buckets on land, and dispose of unwanted bait in trash. After leaving boat launch: Wash all equipment with 104oF water or a high-pressure sprayer or dry equipment for at least five days. Aquarium enthusiasts can help, too, by never dumping aquaria water or aquarium organisms into local lakes or streams (Stoeckel and Charlebois, 1999).
