Morphological ontogeny of Platynothrus troendelagicus sp. nov. (Acari, Oribatida, Camisiidae) from Norway

Abstract

The morphological ontogeny of Platynothrus troendelagicus A. et S. Seniczak sp. nov. is described and illustrated. This species was found in two Atlantic raised bogs in Trøndelag, Norway, and based on comparison of cytochrome oxidase I (COI) nucleotide sequences, it also occurs in Ireland and Canada. It is the most similar to P. punctatus (L. Koch, 1879) as adult, but differs from it mainly by having more genital setae, longer seta f2, alveolar seta exp and only one pair of hypostomal setae m. In all juveniles of P. troendelagicus, the bothridial seta and exobothridial seta exa are short, and exp is alveolar. In the larva, seta f1 is setiform, but in the nymphs it is alveolar. Most prodorsal and gastronotal setae are short and smooth, except for longer and barbed f2 and h1 in the larva, and longer and finely barbed f2, and h- and p-series in the nymphs. In all instars, one pair of hypostomal setae m is present, and palp femur has one seta. In the ontogeny of this species, many l setae appear on trochanter III and femora I–III, and l and v setae on tarsi, and the number of setae on femora of deutonymph to adult is diagnostic. Both species differ also by COI nucleotide sequence.