Assessing the Extinction Risk of Heterocypris incongruens (Crustacea: Ostracoda) in Climate Change with Sensitivity and Uncertainty Analysis

Organisms respond to climate change in many different ways and their local extinction risk may vary widely among taxa. Crustaceans from freshwater temporary ponds produce resting eggs to cope with environmental uncertainty and, as a consequence, egg banks have a fundamental role for population persistence. The egg bank dynamics of six clonal lineages of Heterocypris incongruens (Ostracoda) from Northern Italy were simulated. Clonal lineages W1 and W2 are the most common “winter ecotypes”, clonal lineages S1 and S2 are allochthonous “summer ecotypes” and clonal lineages I1 and I2 are relatively rare and generalist in terms of seasonality. Fecundity and proportion of resting eggs vary by clonal lineage, temperature and photoperiod. The clonal extinction risk was estimated in present climate conditions and under climate change. For comparison, and to assess the potential colonization of northern ponds, clonal lineages from Lampedusa Island (Southern Italy), L, were considered. Cohen’s general model was used for simulating egg bank dynamics and the extinction rate of each clonal lineage was estimated with uncertainty analysis. A 30 year simulation in present and climate change conditions was carried out. Extinction rates were lower in climate change conditions than in present conditions. Hydroperiod, hatching rate and egg deterioration rate were the critical factors that affected extinction rates. Extinction rates varied among clonal lineages. This suggests that H. incongruens might be able to have multiple responses to climate change due to its genetic diversity. In climate change conditions, W clonal lineages underwent a niche expansion, while a mismatch between photoperiod and hydroperiod might generate a detrimental effect on the phenology of summer S clonal lineages that might cause their extinction. Southern clonal lineages L, showing an intermediate extinction rate, might colonize northern temporary ponds.

The Effect of New Thiophene-Derived Diphenyl Aminophosphonates on Growth of Terrestrial Plants

The aim of this work was to evaluate the impact of the thiophene-derived aminophosphonates 1–6 on seedling emergence and growth of monocotyledonous oat (Avena sativa) and dicotyledonous radish (Raphanus sativus L.), and phytotoxicity against three persistent and resistant weeds (Galinsoga parviflora Cav., Rumex acetosa L., and Chenopodium album). Aminophosphonates 1–6 have never been described in the literature. The phytotoxicity of tested aminophosphonates toward their potential application as soil-applied herbicides was evaluated according to the OECD (Organization for Economic and Cooperation Development Publishing) 208 Guideline. In addition, their ecotoxicological impact on crustaceans Heterocypris incongruens and bacteria Aliivibrio fischeri was measured using the OSTRACODTOXKITTM and Microtox® tests. Obtained results showed that none of the tested compounds were found sufficiently phytotoxic and none of them have any herbicidal potential. None of the tested compounds showed important toxicity against Aliivibrio fischeri but they should be considered as slightly harmful. Harmful impacts of compounds 1–6 on Heterocypris incongruens were found to be significant.

Niche overlap and ecological tolerance of non-marine Ostracoda in Turkey

We applied niche overlap indices to for the first time show possible correlational occurrences among 40 non-marine ostracod taxa from seven aquatic habitats (lakes, creeks, ponds, springs, ditches, pools, troughs) in Turkey. Ecological tolerance and optimum estimates of each species were calculated and compared to explain possible reasons for habitat utilization. Eleven species were found suitable for the application of these indices. Overlap ranges of five of the species were found suitable for five variables (pH, dissolved oxygen, water temperature, electrical conductivity, and elevation; P < 0.05). Heterocypris incongruens (Ramdohr, 1808) and H. salina (Brady, 1868) were the only two species with common overlap for all the five variables. These two species generally showed common resource-utilization curves for each of these variables along with relatively similar tolerance ranges. Complete overlap was only possible for some cosmoecious species when they displayed wide-tolerance ranges and low optimum estimates for different environmental variables. Results suggest that cosmopolitan species do not only have wide geographical distributions but tolerance ranges higher than other species. Such wide tolerance ranges seem to help species coinhabit with each other and elevate their co-occurrence probabilities in different types of habitats. Applying the first usage of overlap indices on ostracods and attempting to show the relationship between niche overlap and species ecological tolerance could nevertheless provide a new tool to apply in future studies.