Life history of Karualona muelleri (Richard, 1897) (Chydoridae, Aloninae)

Many taxonomic issues still need to be solved for the family Chydoridae, but mainly in the subfamily Aloninae. The species Karualona muelleri is an example of a recent taxonomic redefinition, since it was decoupled from the genus Alona and translocated to another genus. In order to expand our knowledge on the species, we investigated population growth and compared the morphometry of the first and second instars, male, parthenogenetic female, ephippial female, and ephippium. An experimental population was obtained by hatching resting eggs collected from the sediment in a temporary lake located in the Serra da Canastra National Park (Minas Gerais, Brazil). The hatched individuals were subjected to morphometric analyses and used in experiments to assess population growth and fecundity. Reproductive age and lifespan were also monitored in two groups of females in different life stages: parthenogenetic and gamogenetic. The reproductive age occurred between the 1st and 15th days of life, and the greatest longevity was 17 days. The start of gamogenetic reproduction was stimulated by elevated population densities and it characterized the slowdown of exponential population growth. Morphometric analyses detected differences between the development phases, as well as similarities in the morphological features of the male, first and second instars, and the two types of females.</jats:p

Establishment of a new genus for Parastenocaris itica (Copepoda, Harpacticoida) from El Salvador, Central America, with discussion of the Parastenocaris fontinalis and P. proserpina groups

A new genus of Parastenocarididae is described from the Neotropical region. Iticocaris gen. nov. is established to include Parastenocaris itica Noodt, 1962. Iticocaris gen. nov. is defined by the following characters: 1) male leg 3 with 2-segmented exopod; 2) first exopodal segment short and rectangular; 3) thumb hypertrophic, longer than the second exopodal segment and inserted on the distal edge of exopod segment 1, occupying the whole distal margin; 4) exopod 2 or apophysis strongly sclerotized, articulated with the exopod segment 1 on its inner margin and curved against the thumb, forming a strong forceps; 5) leg 4 endopod without dimorphism in shape and size vs. minor dimorphism in ornamentation; 6) leg 5 with three setae and 7) lack of the anterolateral furcal seta II. The new genus is monotypic, represented by Iticocaris itica (Noodt, 1962) comb. nov., from El Salvador, Central America. A close relationship is hypothesized between I. itica and the genus Brasilibathynellocaris Jakobi, 1972, the males of which both share the forceps-like elongated apophysis