Caenis vanuatensis, a new species of mayflies (Ephemeroptera: Caenidae) from Vanuatu

Abstract

The first species of Caenidae from Espiritu Santo, Vanuatu, is described based on the larva and the female imago. Caenis vanuatensis sp. n. is most likely a parthenogenetic species, as only females have been found so far out of numerous specimens collected. The phylogenetic relationships of the new species thus remain enigmatic, as the distribution of Caenis throughout the Australian region is largely unknown and the taxonomically important males are missing.

First contribution to the mayflies of Jordan

“…In some of the localities, it co-occurs with C. parabrevipes. C. antoniae can be easily distinguished from other species of the genus, and especially from C. parabrevipes, by the deep emargination of the IX sternite and the long and abundant setae on the lateral margin of abdominal segments (MALZACHER 1992). As noted in the original description, the size of full-grown larvae is highly variable between and among populations (MALZACHER 1992).…”

“…In Jordan, Caenis parabrevipes is less common and less abundant than C. antoniae. It can be identified by the short posterolateral extension of the abdominal segments, small and shallow indentation of the IX sternite, and the tergites VIII and IX with a restricted number of medium setae (MALZACHER 1992). This species was described from a tributary of the Dead Sea area, where it was relatively abundant, but was not found in nearby watercourses (SARTORI 1992) and has not been mentioned since then.…”

“…Four species of Caenidae, Caenis macrura Stephens, 1835, Caenis antoniae Malzacher, 1992, Caenis gilbonensis Malzacher, 1992, Caenis parabrevipes Malzacher, 1992, were reported from Israel by MALZACHER (1992) who provided a useful key to identify the larvae. The main characters are the shape of the IX sternite, the setation of the lateral margins of the abdomen and the degree of development of the posterolateral extension of the abdominal segments (referred to as spines of the hind corners of the abdominal segments in MAL-ZACHER 1992).…”

“…In the material examined, only C. antoniae and C. parabrevipes were discovered. According to MALZACHER (1992), these two species are related to Afrotropical species. This species, described and only known from a tributary of the Dead Sea, is quite common and widely distributed in Jordan.…”

“…Shortly after this, the Heptageniidae were studied in detail with the description of six new species belonging to five different genera (DEMOULIN 1973). Subsequently, Caenidae, Ephemerellidae, Leptophlebiidae and Palingeniidae were subject to complete taxonomic and faunistic studies, with the description of four new species that are so far only known from Israel (MALZACHER 1992, SARTORI 1992. The fauna of Israel presently encompasses 15 species, but the study of the Baetidae, which is probably the most common and diversified family of mayflies, is still in progress.…”