The taxonomy and aspects of the ecology of the Ephemeroidea (Insecta: Ephemeroptera) of the Mooi River, KwaZulu-Natal Province, Republic of South Africa.
Thesis (M.Sc.)-University of KwaZulu- Natal, Pietermaritzburg, 2004.The Ephemeroidea or burrowing mayflies are a superfamily of the Ephemeroptera
(mayflies) with a worldwide distribution. Recent decades have seen a sharp decline
in their abundance globally. Literature reviews of the past 20 years have shown this
superfamily to be well represented on the Mooi River, KwaZulu-Natal- five species
(Eatonica schoutedeni, Ephemera mooiana, Afromera natalensis, Afroplocia sampsoni
and Ephoron savignyi) were recorded during the 20th century. However recent
fieldwork failed to confirm this professed diversity, recording only two species
(Afromera natalensis and Ephoron savignyi).
This work critically re-examined all of the literature relating to the
Ephemeroidea of Africa (in the context of the five species recorded from KwaZuluNatal)
published in Africa and Europe (as well as many publications from the rest of
the world) during the 19th and 20th century. It was found that a number of oversights
were made in much of this literature that have become assimilated into the
understanding of the taxonomy and ecology of this group. Amongst these, it was
found that the synonymisation of three species of Ephoron
( = Polymitarcys-Polymitarcys savignyi, P. capensis and P. temerata) in the 1920s was
weakly justified.
To clarify problems in the published record relating to the five species
recorded from KwaZulu-Natal, some of the most important museum holdings in
Europe and South Africa were re-examined. Two previously unknown collections of
Ephemera sp. were found in European museums. One of these collections was made
in West Africa, undermining theories that Ephemera sp. are only found in cold
waters. This research confirmed that the records for Eatonica schoutedeni in
KwaZulu-Natal are probably spurious, the result of misidentification. This work
presents a review of the publications relating to each of the species of the
Ephemeroidea recorded from KwaZulu-Natal. Lists of synonyms are provided.
Descriptions from literature and museum specimens are given. The known
distribution and biology of each is presented. The current status of the Ephemeroidea
of KwaZulu-Natal are discussed and a new key to the species of Kwazulu-Natal is
presented.
In order to assess the purported diversity of Ephemeroidea in the rivers of the
KwaZulu-Natal midlands, extensive fieldwork was carried out the Mooi River and on
other tributaries of the Tugela and Mgeni rivers from 1998 to 2000. This investigation
failed to reveal four of the five species indicated in the literature. The sole species that
was found, Ephoron savignyi was abundant in some areas of the Mooi and Karkloof
Rivers. This apparent drop in diversity may be because the sampling effort carried out
from 1998 to 2000 was too limited in time and space to gather specimens of all the
species resident in the river, or because environmental changes in the region in the
last 50 years have resulted in the extirpation of any or all of the remaining four
species.
It is concluded that the records of Eatonica schoutedeni from KwaZulu-Natal
are spurious; Ephemera mooiana is either not the only species in the genus Ephemera
on the continent of Africa, or has a substantially wider distribution than previously
thought; Afromera natalensis and Afroplocia sampsoni may be present on the rivers
of KwaZulu-Natal but have not been found during this research; Ephoron spp. are
abundant in KwaZulu-Natal, but further research is required to confirm that the
species in South Africa are the same as those originally recorded from the type
locality, Egypt
