Russian and French zoologists discover new poisonous shellfish species
"The structural changes in genes between two groups of organisms are not always sufficient to conclude on which belong to any species."
Russian scientists from the A.N. Severtsov Institute of Ecology and Evolution at the Russian Academy of Sciences (IPEE) in collaboration with French colleagues from the National Museum of Natural History (Paris) have discovered three new species of poisonous shellfish which were considered to be of one single species before, the press office of IPEE stated. The research article on the project has been published in the Journal of Molluscan Studies, TASS reports.
The species of poisonous carnivorous sea gastropods Crassispira cerithina which was believed to be well-studied represents, in fact, a species complex of four different species, three of which are new to science.
The researchers gained the understanding that different species have been unified under one name by a combination of morphological analysis (the method for classifying species where the external and internal structure are analyzed) with molecular phylogenetic methods. The co-analysis within two approaches demonstrates that the diversity of species is underestimated, as in nature there exist aggregates of similar species which had not been previously differentiated by scientists.
"The structural changes in genes between two groups of organisms are not always sufficient to conclude on which belong to any species. That is why we have made use of the taxonomic approach, that is, using all possible complementary data sources including traditional morphology and biogeography to confirm species hypothesis. The concept of integrative taxonomy was first formulated by an American zoologist of French origin, Benoot Dayrat," leader of the research team, Doctor of Biological Sciences Yuri Kantor commented.
The poison of the carnivorous shellfish has a great variety of potential application for pharmacological usage. The "raw" poison of shellfish is like a cocktail consisting of dozens or even hundreds of peptides. Concerning the quasi well-described "species" Crassispira cerithina, two research articles have been published where the poisonous secretion has been described but the authors of those studies were not aware that they were dealing with an entire species aggregate.
"When toxicologists research the poison, they have to destroy the sample. However, while replicating the experiment, they could not find the sought after substances as they did not deal with a unique species but as we have shown with several ones. The ... work could be undertaken in vain if not preceded by taxonomic analysis," Kantor noted, while explaining the practical interest to the study of biodiversity.