Cryptic diversity in the mayfly Leptohyphodes inanis (Pictet) (Ephemeroptera: Leptohyphidae) across water basins in Southeastern Brazil

The Genetic Diversity and the Divergence Time in Extant Primitive Mayfly, Siphluriscus chinensis Ulmer, 1920 Using the Mitochondrial Genome

In this study, the mitochondrial (mt) genomes of Siphluriscus chinensis (Ephemeroptera: Siphluriscidae) were evaluated in specimens collected from two sites in China: Niutou Mountain, Zhejiang Province (S. chinensis NTS) and Leigong Mountain, Guizhou Province (S. chinensis LGS) and were successfully sequenced. The lengths of the mt genomes of S. chinensis NTS and S. chinensis LGS were 15,904 bp (ON729390) and 15,212 bp (ON729391), respectively. However, an in-depth comparison of the two mt genomes showed significant differences between the specimens collected from the two sites. A detailed analysis of the genetic distance between S. chinensis NTS and S. chinensis LGS was undertaken to further achieve an accurate delimitation of S. chinensis. The genetic distance between S. chinensis NTS and the other three species within Siphluriscidae was a high value, above 12.2%. The two mt genomes were used to reconstruct phylogenetic relationships and estimate divergence time. The results demonstrated robust differences between S. chinensis NTS and S. chinensis LGS, which revealed that a kind of cryptic species existed. Maximum likelihood (ML) and Bayesian inference (BI) analyses produced well-supported phylogenetic trees that showed evolutionary relationships between Siphluriscidae (((S. chinensis HQ875717 + S. chinensis MF352165) + S. chinensis LGS) + S. chinensis NTS). The most recent common ancestor (MRCA) of four species within Siphluriscidae began to diversify during the Neogene [11.80 million years ago (Mya); 95% highest posterior densities (HPD) = 6.17–19.28 Mya], and S. chinensis NTS was first to diverge from the branches of S. chinensis LGS. In short, based on mitochondrial genomes, our results showed that the specimens collected from Leigong Mountain, Guizhou Province (S. chinensis LGS) belonged to S. chinensis, and the specimens collected from Niutou Mountain, Zhejiang Province (S. chinensis NTS) were a cryptic species of S. chinensis.

A new species of Tricorythodes Ulmer from Colombia and additional notes on T. serratus (Baumgardner & Ávila) (Ephemeroptera: Leptohyphidae)

A new species of Tricorythodes is described and illustrated based on nymphs from Colombia. Legs, mouthparts and other parts of the body were photographed through SEM and molecular characterization was performed by amplification of the COImt gene. Tricorythodes carare sp. nov. shows close affinities with T. serratus (Baumgardner & Ávila), both sharing a similar coloration pattern and the presence of chalazae on femora. The new species can be distinguished from T. serratus and all the species of the genus by the following combination of characters: maxillary palp 3-segmented, with apical setae; dorsal surface of median and hind femora with a longitudinal row of 5 to 9 chalazae serrated in the apex, tarsal claws with 4 or 5 marginal denticles and with 1–3 submarginal denticles; posterior margin of the abdominal terga with serrated chalazae in the apex. SEM images and distance analysis of the partial sequences of the COI gene were useful to discriminate the new species from T. serratus (genetic divergence 17–19%). An additional undescribed species of this group is reported from Esmeraldas in Ecuador and for the departments of Sucre and Chocó in Colombia, but it is not described here because of the low number of individuals and the lack of DNA integrity. What is known under the name Tricorythodes serratus is suspected to be a species complex.