Peronia

Abstract: The diatom subclass Eunotiophycidae has recently expanded in composition. While it still includes a single order, the Eunotiales, and two families, the Eunotiaceae and Peroniaceae, the former includes four genera, Eunotia, Actinella, Semiorbis and Desmogonium, while the Peroniaceae includes only one, the genus Peronia. After discovery of the predominantly Southern Hemisphere genus Eunophora, a freshwater taxon superficially resembling species of Amphora, other species of diatoms with similarly confusing morphology have come into sharper focus. The recently described genus Amphorotia, based on Eunotia clevei, may be sister taxon (its most closest relative) to Eunophora. This paper presents evidence for including a Miocene, marine, fossil species, Eunotia reedii, with the more or less tropical species, Amphora reichardtiana, in the same genus. Relationships among the Eunotiaceae are further clarified.

Abstract: A new genus of the diatom family Eunotiaceae Kutzing is described along with a new species. Eunotioforma Kociolek & Burliga gen. nov . shares asymmetry about the apical axis with other members of the family (except Peronia de Brebisson & Arnott ex Kitton ), and is distinguished from other genera in the family by having its raphe system almost entirely on the valve face and transapical striae interrupted near the center line of the valve. Eunotioforma mattogrossiana sp. nov. is described from the Do Sangue River, an oligotrophic and acidic stream situated in the State of Mato Grosso, Central Western region of Brazil. When compared with previously described taxa, the new species differs with respect to size, striae densities, areolar densities and an uncommonly high number of rimoportulae per valve. Seven other taxa are assigned to the new genus, and the systematic position of Eunotioforma and the evolution of the raphe within the family is discussed.

Abstract: As a nutritious mollusk living in the intertidal zone, Onchidiidae has a significant value for biological research. Nine populations were collected from the costal areas such as Chongming (Shanghai), Ningde (Fujian), Haikou (Hainan) in this study. Through the study of anatomy and other methods to investigate the major category characteristics, the nine populations were preliminary classified. By sequencing segments of 18S rRNA gene and constructing phylogenetic trees using these nine populations and four other 18S rRNA gene sequences from GenBank, with Siphonaria as an outgroup, we analyzed the phylogeny of Onchidiidae in mainland China. The trees were used for discussing the relationship between the populations of the Onchidiidae in this study. The results showed that the southern coast has more populations than the northern coast in China. Besides two known species, Onchidium struma (JZH) and O. verruculatum (FJZ & HNZ), five new recorded species may exist: Onchidium(1), Platevindex(2), one Peronia(1) and Paraoncidium(1). The phylogenetic trees indicated that the nine populations can be divided into four subgroups, Peronia, Onchidium, Platevindex and Paraoncidium, and Peronia has the highest confidence level in clustering. Onchidium verruculatum (FJZ & HNZ) should be Peronia verruculata.

Abstract: Eunotia is a diatom genus characterized by a short raphe system restricted to both valve poles and by the presence of rimoportulae. As part of a survey examining the genus, Eunotia enigmatica sp. nov. is described from ultra oligo- to oligotrophic and slightly acidic reservoirs in Sao Paulo State, southeast Brazil. The species is unusual in having a short distinct raphe, and a 'fragilarioid' appearance with long cells and marginal spines. It was commonly found in the planktonic community as well as on sediments of the studied reservoirs. It seems to be adapted to an open water existence, and is similar to E. croatana and E. pseudofragilaria both described from North America. Additionally, type material of another similar looking species, Fragilaria braunii, was analysed using light and scanning electron microscopy and a new combination is proposed for it in the genus Peronia.