Search results for "Branchiopod"

Daphnia magna feeding behavior after exposure to tetradifon and recovery from intoxication.

1999

Abstract The feeding behavior of the cladocera Daphnia magna subjected to a short-term exposure to the acaricide tetradifon (4-chlorophenyl 2,4,5-trichlorophenyl sulfone) was studied. The experiments were performed using the unicellular algae Nannochloris oculata at a density of 5×10 5 cells/ml as food for the organisms. In a first experiment, three generations (F0, F1, and F3) of the daphnids were exposed to sublethal levels of tetradifon (0.1, 0.18, 0.22, and 0.44 mg/l) and the effect of the toxicant on filtration and ingestion rates was determined. Rates of filtration and ingestion of D. magna declined in the three generations studied with increasing toxicant concentrations; however, tox…

Population dynamics in Daphnia magna as modified by chronic tetradifon stress.

2000

Two Daphnia magna offsprings (animals from the first and third brood) whose parentals (F0-generation) were exposed during 21 days to different tetradifon (4-chlorophenyl 2,4,5-trichlophenyl sulfone) concentrations, were transferred to a pesticide free medium during 21 days (recovery period). The algae Nannochloris oculata (5 x 10(5) cells/mL) was used as food. In this recovery study, survival, growth and reproduction (mean total young per female, mean brood size, onset of reproduction and mean number broods per female) were assessed as individual parameters and the intrinsic rate of natural increase (r) as population parameter, for F1 generation (1st and 3rd broods). Reproduction was still …

A hidden species becoming visible : biogeography and ecology of Rhynchotalona latens (Cladocera, Anomopoda, Chydoridae)

2019

A long hidden chydorid (Chydoridae, Cladocera) taxon, first found as fossil specimens and recently redefined as Rhynchotalona latens (Sarmaja-Korjonen et al., Hydrobiologia 436: 165-169, 2000) is investigated for its biogeography and ecology. Late Holocene sediment sequence from Lake Sylvilampi, NE Finnish Lapland, and R. latens spatial distribution in relation to limno-climatic attributes in Finland were examined. Principal component analyses of fossil cladoceran communities showed that R. latens is mostly affiliated with Alonella excisa-Alonopsis elongata-Alonella nana species pool. Generalized linear modeling of R. latens responses to limno-climatic variation indicated that it prefers ac…

Ecological characterization and cladocerans, calanoid copepods and large branchiopods of temporary ponds in a Mediterranean island (Sicily, Southern …

2006

Temporary waters have been sporadically investigated in Sicily. These environments reflect the climatic features of the Mediterranean area with a winter ponding phase and a more or less prolonged dry period in summer. Their biota, especially those organisms strictly linked to aquatic environments and without any terrestrial life stage, have to exhibit special adaptations to survive the dry phases that are recurrent in such ecosystems. This study included more than 250 water bodies distributed on the whole Sicilian territory and on the small circum-Sicilian islands. This paper represents a first attempt to characterize Sicilian temporary waters from an ecological point of view and is mainly …

First record of the tadpole shrimp triops cancriformis (Branchiopoda, Notostraca) in Cyprus

2014

The presence of the large branchiopod Triops cancriformis (Bosc, 1801-1802) in Cyprus is reported for the first time. Triops cancriformis individuals were observed in the large temporary wetland of Paralimni Lake (Famagusta District, Cyprus) during the wet periods of 2013 and 2014. This finding extends the current knowledge of the species distribution in the eastern Mediterranean area, and stresses the ecological and conservation value of the unique habitat of Paralimni Lake. In addition, it highlights the need for carrying on further studies on the fauna of temporary pond habitats in Cyprus, and for better conservation management strategies for such EU priority habitats.

A new Northeast Asian Lynceus (Crustacea: Branchiopoda: Laevicaudata) with uniquely modified thoracopods and an evaluation of DNA barcoding for clam …

2020

A new species of smooth clam shrimp (Branchiopoda: Laevicaudata) from Mongolia and China is described here based on both morphological and genetic differences. The new species, Lynceus grossipedia n. sp., has unique features, including asymmetrically modified male thoracopods (left side thoracopods III-VI), male claspers “movable finger” (=endopod) with delicate setation, and broad, bicarinate male and female rostrum. Lynceus grossipedia n. sp. is compared with the genera Paralimnetis Gurney, 1931 and Lynceiopsis Daday, 1912 and a recently described Lynceus Müller, 1776 from China, also showing modified male thoracopods. Lynceus mandsuricus Daday, 1927 is declared nomen inquirendum. DNA bar…

Pleistocene allopatric differentiation followed by recent range expansion explains the distribution and molecular diversity of two congeneric crustac…

2021

AbstractPleistocene glaciations had a tremendous impact on the biota across the Palaearctic, resulting in strong phylogeographic signals of range contraction and rapid postglacial recolonization of the deglaciated areas. Here, we explore the diversity patterns and history of two sibling species of passively dispersing taxa typical of temporary ponds, fairy shrimps (Anostraca). We combine mitochondrial (COI) and nuclear (ITS2 and 18S) markers to conduct a range-wide phylogeographic study including 56 populations of Branchinecta ferox and Branchinecta orientalis in the Palaearctic. Specifically, we investigate whether their largely overlapping ranges in Europe resulted from allopatric differe…

Branchiopod crustaceans from circum-Sicilian islands, I: Ustica (Southern Tyrrhenian Sea, Italy) (Crustacea Branchiopoda)

2003

The microcrustacean fauna of Sicily and the Central Mediterranean Sea area - Current knowledge and gaps to be filled

2006

The current knowledge of freshwater entomostracans from Sicily and some neighbouring central-Mediterranean countries is briefly reviewed. Data concerning different countries and different taxonomical groups are markedly inhomogeneous and often far from being representative of the real biota of the corresponding countries. This gap prevents a sound biogeographical analysis of the freshwater microcrustacean fauna of the area. The major gaps that have to be filled are highlighted and the need for more surveys and monitoring is emphasised.

First record and morphological features of Hemidiaptomus (Occidodiaptomus) ingens (Gurney, 1909) (Copepoda Calanoida) in Italy

2004

During a survey, carried out to assess the consistency of microcrustacean fauna inhabiting temporary ponds in Sicily, Hemidiaptomus (Occidodiaptomus) ingens (Gurney, 1909), a large calanoid copepod up to now known only for North-African ponds, Camargue and Corse, was found in the north-western part of the island. Due to its central location in the Mediterranean Sea, Sicily represents a transition zone where several chorological zones of the West Palearctic merge and converge. A brief summary of the existing literature regarding this taxon is given with some morphological considerations on the recently found population which represents the first record for Italy. In particular, the morpholog…