Predator‐specific inducible morphological defenses of a water flea against two freshwater predators

The purpose of this study is to is to examine the secondary spread of Bythothephes longimanus, commonly known as spiny water flea, across inland lakes in Ontario, and potentially determine predictors for the its invasion. Data for 190 inland lakes across 84 quaternary watersheds in Ontario were included in the database. Global Moran's I was used to analyze the spatial autocorrelation of the variables, and McFadden's Rho-Squared was used to determine if a variable was a predictor of invasion. Three independent variables, out of 28, were found to be good predictors of invasion: (1) mean temperature of watersheds during summer (MNTMPWSSU), (2) mean precipitation for watersheds during spring (MNPCPWSSP), and (3) mean precipitation for watersheds during summer (MNPCPWSSU). Of the three, mean precipitation for watersheds during summer was determined to be the best predictor.

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Effect of heavy metal, copper sulphate and potassium chromate on behaviour of “Tailless water flea” Simocephalus vetulus (Crustacea - Cladocera)

Journal of Applied and Natural Science ◽

10.31018/jans.v10i1.1659 ◽

2018 ◽

Vol 10 (1) ◽

pp. 507-517

Author(s):

Anand Mishra ◽

Sanjive Shukla ◽

A. K. Chopra

Keyword(s):

Aquatic Ecosystem ◽

Copper Sulphate ◽

Well Being ◽

Potassium Chromate ◽

Water Flea ◽

Simocephalus Vetulus ◽

Lc50 Value ◽

Aquatic Flora ◽

Excess Quantity ◽

Activity Loss

Water fleas constitute major zooplankton population of fresh water aquatic ecosystem. Their population density is an indicative of well-being of aquatic bodies. Simocephalus vetulus (Crustacea - Cladocera) is a tailless water flea and is well suited lab model for environmental monitoring. Copper a Gray listed heavy metals despite being an essential micronutrient, becomes highly toxic when present in excess quantity in aquatic ecosystem thereby causing deleterious effects on aquatic flora as well as fauna. The water-flea exposed to acute 0.37 mg/l (96hr LC50), sub-acute 0.0925 mg/l (25% of 96hr LC50) value and chronic 0.037 mg/l (10% of 96hr LC50) value of copper sulphate and acute 0.16 mg/l (96 hr LC50), sub-acute 0.04 mg/l (25% of 96 hr LC50) value and chronic 0.016 mg/l (10% of 96 hr LC50) value of potassium chromate showed behavioural alterations like initial hyperactivity, fast appendage movements and in phototaxis, geotaxis and avoidance indices. At later stage erratic swimming and spinning, reduced activity, loss of balance, reduced feeding and darkening of cuticular coloration, reduced phototactic, geotaxis and avoidance indices were the major effects on its behaviour. The behavioural alterations of S. vetulus showed the most susceptible and foremost indication of potential toxic effects. Various behavioural parameters, used in present study may serve as better biomarkers about metal toxicity and monitoring of drinking water quality

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Genetic Signature of a Past Anthropogenic Transportation of a Far-Eastern Endemic Cladoceran (Crustacea: Daphniidae) to the Volga Basin

Water ◽

10.3390/w13182589 ◽

2021 ◽

Vol 13 (18) ◽

pp. 2589

Author(s):

Dmitry P. Karabanov ◽

Petr G. Garibian ◽

Eugeniya I. Bekker ◽

Rimma Z. Sabitova ◽

Alexey A. Kotov

Keyword(s):

Species Complex ◽

Morphological Traits ◽

Far East ◽

Volga Basin ◽

28S Rrna ◽

Water Flea ◽

The Far East ◽

Nuclear Loci ◽

Cryptic Invasions ◽

Far Eastern

Most studies of water flea (Crustacea: Cladocera) invasions are concentrated on a few taxa with an obvious harmful influence on native ecosystems, while our knowledge of cases of anthropogenic introduction with not-so-obvious consequences, in most other taxa, is poor. We found in the Volga basin (European Russia) a population that contained D. curvirostris Eylmann, 1887 and its hybrids with D. korovchinskyi Kotov et al. 2021. The latter taxon is endemic to the Far East and it has appeared in the Volga basin as a result of past human-mediated transportation. The population from Bakhilovo is represented by two strongly different groups of the COI haplotypes belonging, respectively, to (1) D. curvirostris and (2) D. korovchinskyi. We detected SNPs in the position 60 of the HSP-90ex3 locus and in the 195 positions of 28S rRNA locus, which differentiate two species. Part of the specimens from Bakhilovo belonged to D. curvirostris s.str., demonstrating homozygote SNP sites in two loci, but two specimens had heterozygote SNP sites in both nuclear loci. They belong to D. curvirostris x korovchinskyi hybrids. Most morphological traits of the females were characteristic of D. curvirostris. We found in some specimens some characters which could suggest their hybrid status, but this opinion is a hypothesis only, which needs to be checked on more ample material. The exact hybrid system in this pond is not known. Moreover, we have no evidences of sexual reproduction of the hybrids; they could reproduce by parthenogenesis only as is known for hybrids of the D. pulex group, or continuously crossing with parents like some members of D. longispina group. However, poor parental D. korovchinskyi was not detected in the pond either morphologically or genetically. The exact vector of its past anthropogenic transportation to the Volga is unknown. Most probably, just ephippia of D. korovchinskyi were translocated replaced from the Khabarovsk Territory to the Samara Area somehow. This is the first report on hybrids within the D. curvirostris species complex. Here, we demonstrated that accurate studies with deep resolution increase the number of revealed cryptic invasions. We expect that the number of revealed cases of cryptic interspecific invasions will grow rapidly.

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