An Asiatic Chironomid in Brazil: morphology, DNA barcode and bionomics.

Gizelle Amora,Vanderly Andrade-Souza,Neusa Hamada,Lívia Maria Fusari

doi:10.3897/zookeys.514.9925

Gizelle Amora, Vanderly Andrade-Souza + Show 2 more

Open Access

https://doi.org/10.3897/zookeys.514.9925

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Abstract

In most freshwater ecosystems, aquatic insects are dominant in terms of diversity; however, there is a disproportionately low number of records of alien species when compared to other freshwater organisms. The Chironomidae is one aquatic insect family that includes some examples of alien species around the world. During a study on aquatic insects in Amazonas state (Brazil), we collected specimens of Chironomidae that are similar, at the morphological level, to Chironomus kiiensis Tokunaga and Chironomus striatipennis Kieffer, both with distributions restricted to Asia. The objectives of this study were to provide morphological information on this Chironomus population, to investigate its identity using DNA barcoding and, to provide bionomic information about this species. Chironomus DNA barcode data were obtained from GenBank and Barcode of Life Data Systems (BOLD) and, together with our data, were analyzed using the neighbor-joining method with 1000 bootstrap replicates and the genetic distances were estimated using the Kimura-2-parameter. At the morphological level, the Brazilian population cannot be distinguished either from Chironomus striatipennis or Chironomus kiiensis, configuring a species complex but, at the molecular level our studied population is placed in a clade together with Chironomus striatipennis, from South Korea. Bionomic characteristics of the Brazilian Chironomus population differ from the ones of Chironomus kiiensis from Japan, the only species in this species complex with bionomic information available. The Brazilian Chironomus population has a smaller size, the double of the number of eggs and inhabits oligotrophic water, in artificial container. In the molecular analysis, populations of Chironomus striatipennis and Chironomus kiiensis are placed in a clade, formed by two groups: Group A (which includes populations from both named species, from different Asiatic regions and our Brazilian population) and Group B (with populations of Chironomus kiiensis from Japan and South Korea). Genetic distance between the Brazilian population and specimens in Group A suggests that it was recently introduced in Brazil, and that its country of origin is probably South Korea.

Highlights

Alien species represent one of the most serious threats to biodiversity at different taxonomic levels (Mack et al 2000) including freshwater ecosystems (Gherardi 2007)
The morphology of the Brazilian Chironomus population is identical to that presented in the original descriptions of C. striatipennis and of C. kiiensis (Kieffer 1910; Tokunaga 1936), and in other taxonomic papers on these two species (Chaudhuri et al 1992; Martin 2014), it being impossible to distinguish them from each other morphologically
In the neighbor-joining tree (Fig. 2), we observed that the Brazilian Chironomus population (C. sp1BRA, C. sp2BRA and C. sp3BRA) grouped, with 94% bootstrap support, with others specimens of C. striatipennis and of C. kiiensis from different regions of East Asia

Summary

Introduction

Alien species represent one of the most serious threats to biodiversity at different taxonomic levels (Mack et al 2000) including freshwater ecosystems (Gherardi 2007). Examples include the green crab (Carcinus maenas Linnaeus, 1758), mud crab (Rhithropanopeus harrisii Gould, 1841) and blue mussel (Mytilus galloprovincialis Lamark, 1819), which were recorded being transported in ballast tanks (Briski et al 2012). The Asian tiger mosquito (Aedes albopictus (Skuse, 1894)), which is a vector of the dengue viruses, was introduced in several countries through the importation of tires from Asia (Fontenille and Toto 2001). Despite their dominance in terms of diversity in most freshwater ecosystems, aquatic insects have a disproportionately low number of alien species when compared to other freshwater macroinvertebrates (Karatayev et al 2009). Exceptions include several examples of recognized alien species of Ephemeroptera (Zimmermann 1957), including one in Brazil, a Baetidae species from Africa reported in Brazil’s Espirito Santo state (Salles et al 2014)

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