Acute toxicity of Roundup herbicide to three life stages of the freshwater shrimp Caridina nilotica (Decapoda: Atyidae)
نویسندگان
چکیده
Glyphosate based herbicides, including Roundup , are frequently used in the chemical control of weeds and invading alien plant species in South Africa. These herbicides ultimately get into water courses directly or indirectly through processes such as drifting, leaching, surface runoff and foliar spray of aquatic nuisance plants. Despite their widespread use, no water quality guideline exists to protect indigenous South African freshwater organisms from the toxic effects of these herbicides. The toxicity of the herbicide Roundup was assessed using three different life stages of the freshwater shrimp Caridina nilotica, a prevalent species in South African freshwater ecosystems. Neonate (<7 days post hatching (dph)), juvenile (>7 dph and <20 dph) and adult (>40 dph) shrimps were exposed to varying concentrations (1.5–50 mg/L acid equivalence (a.e.)) of the herbicide in 48 and 96 h acute toxicity tests in order to determine the most sensitive life-stage. The results showed neonates to be more sensitive to Roundup than both juveniles and adults with mean 96 h LC50 values of 2.5, 7.0 and 25.3 mg/L a.e. respectively. The estimated 96 h LC50 of neonates is much lower than the application rate (20–30 mg/L a.e.), although the application’s impact will depend on the dilution rate of the applied concentration in the environment. All three life-stages of unexposed animals exhibited active and coordinated movement but exposed shrimps were erratic and slow in their movements, with neonates showing most of these behavioral irregularities. This study shows that low levels of the herbicide Roundup may adversely affect C. nilotica health and survival. Thus, the herbicide should be carefully managed to minimize any negative impact on non-target freshwater organisms. 2011 Elsevier Ltd. All rights reserved.
منابع مشابه
Caridina simoni Bouvier, 1904 (Crustacea: Decapoda: Caridea: Atyoidea: Atyidae) and the synonymy by Johnson, 1963.
Johnson (1963) attempted to review the 'Caridina nilotica complex' established by Bouvier (1925) and as a result considered several distinct freshwater shrimp species from Indo-West Pacific region as junior synonyms of C. simoni Bouvier, 1904. However, Tiwari and Pillai (1971) indicated the need to clarify the taxonomical status of the many synonyms created by Johnson (1963). Therefore, type an...
متن کاملRadically different scales of phylogeographic structuring within cryptic species of freshwater shrimp (Atyidae: Caridina)
متن کامل
Drawn to the dark side: a molecular phylogeny of freshwater shrimps (Crustacea: Decapoda: Caridea: Atyidae) reveals frequent cave invasions and challenges current taxonomic hypotheses.
Atyid freshwater shrimps are globally distributed and form an important part of freshwater ecosystems, particularly in the tropics and subtropics. Despite their widespread distribution and ecological importance, their phylogenetic relationships are largely unresolved. Here we present the first comprehensive molecular phylogeny of the Atyidae investigating the evolutionary relationships among 32...
متن کاملThree new species of Caridina (Decapoda: Atyidae) from Central Sulawesi and Buton Island, Indonesia, and a checklist of the islands' endemic species.
Three atyid shrimp species of the genus Caridina Milne Edwards, 1837, Caridina boehmei n. sp., C. laroeha and C. butonensis n. sp., are described from the Indonesian islands Sulawesi and Buton. Caridina boehinei n. sp. differs from its apparently next congener C. sulawesi Cai & Ng, 2009 by the shape of the spinulation of the male sexual appendages. Caridina laroeha resembles C. mahalona and C. ...
متن کاملTwo New Species of the Land - Locked Freshwater Shrimps Genus , Neocaridina Kubo
The freshwater shrimp genus, Neocaridina Kubo, 1938, comprises a group of land-locked organisms of the family Atyidae which is distributed throughout Russia, Korea, Japan, China, Taiwan, and Vietnam (Cai 1996, Liang 2004). Unlike the genera Caridina and Macrobrachium with both catadromous and land-locked species, all known species of Neocaridina are land-locked as evidenced by the abbreviated l...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2011