Between 05.08.2013 and 12.08.13, C.E. Fish Essentials owner Chris Englezou and Christodoulos Parmatzias visited various sites within the district of Lemesos, Cyprus in search of the Cypriot Killifish, (Aphanius cf fasciatus). The purpose of our trip was to conduct ichthyological type research on one of just three endemic freshwater fish species native to Cyprus.
After some days exploring the the biodiversity of the rivers which flow into the Kouris Dam, we drove on the 12.08.13 to the wetlands bordering the world reknown Akrotiri Salt Lake in Lemesos, which is a famous pit stop for thousands of African migratory bird species which spend much of the winter months there prior to their annual journey to Europe. We arrived at the reed beds and it was clear that we were looking in the right place, the habitat was perfect for Aphanius. The first problem? It was over-run by millions and millions of introduced Mosquito fish (Gambusia holbrooki). The estimated ratio must have been at least 10,000:1 in favour of the Gambusia in this area, this represents an immense degree of trophic competition; in many areas there were no Aphanius at all.
We observed Gambusia holbrooki show dominant aggression towards the Aphanius during the Aphanius courting behaviour. When the male fish adopted their particular display posture to females (usually more than one female in the vicinity), the Gambusia would respond aggressively by attacking and chasing the Aphanius males. We observed this multiple times and always in the same sequence. I liken this to a complete misinterpretation of the Aphanius behaviour by the foreign Gambusia (perhaps appearing as an aggressive posture or other threat?). After a discussion with Dr Eleni Kalogianni, a leading research associate from the Hellenic Centre for Marine Research in Greece, who has led the conservation program for the Corfu Killifish (now extinct in several locations in Greece) and a species which also coexists alongside Gambusia holbrooki in many places, I understand that this aggressive behaviour by the Gambusia is one of the principle contributing pressures interrupting and inevitably influencing the frequency of reproductive success of Aphanius.
We were able to capture and examine approximately twenty Aphanius here and one noticeable issue was the presence of developmental deformations in several individuals.
The male fish to the left of this photo (and female to the right) was also collected at the same location as the fish in the previous photo and displayed a very unusual morphology. The male was not only very small, but its morphology resembled that of a Gambusia (male Gambusia are also considerably smaller than females). It could be a juvenile male with a morphological deformation, but could this be an example of an adaptation to the competition from the Gambusia? an induced beneficial mutation? Has this fish benefited from this congenital defect? I’m possibly over-thinking things and the suggestion is of course not substantiated with evidence, but it is a very interesting idea.
Ultimately, the combination of environmental pressures being placed on the Aphanius at this location are obvious and extremely concerning; a serious indication to consider the future of this native species which is being out-competed for it’s own habitat here.
The introduced Gambusia / Mosquito fish (here a female). These viviparous fish multiply at a much faster rate than the native oviparous Aphanius; Both eggs and fry of Aphanius are consumed by the Gambusia.
The water specifications at two locations we sampled here were as follows: Temperature – 29.4°C & 26.4°C, TDS 229 ppt & 321 ppt, pH 9 & 8.7, gH ~20 & 21, kH 15 & 10.
Aphanius cf fasciatus are known at only two other locations on the island of Cyprus, one at the Glapsides lagoon, Ammochostos, Famagusta where S. Zogaris & S. Gucel re-discovered a living population in July 2012 and the second at the Silver Beach Lagoon near to Ancient Salamis where S. Zogaris & S. Gucel reported a mass death of over 20,000 Aphanius in 2012 due to the water completely drying up – the result of water removal for human use with no sustainable management program.
Mass death of 20,000 Aphanius in 2012 at Silver Beach Lagoon.
A small group of 20 fish from Akrotiri shortly after capture
Female Aphanius and Gambusia together
It seems as though the plight of the Mediterranean Toothcarp is both going largely unnoticed and its presence taken for granted in Cyprus. With such intense environmental and multiple anthropogenic pressures threatening the future of Aphanius cf fasciatus on the island of Cyprus, I hope to enlighten organisations such as the IUCN, who are (without trying to offend) failing this species (a potential unique subspecies) by classifying it as “Least Concern” on their RedList despite different populations experiencing varying degrees of pressure (such as those in Cyprus). There is an urgent need for the IUCN redlist to upgrade to a more meticulous approach of measuring the conservation status of individual populations instead of only the existence of a species on Earth. If the IUCN would measure conservation status by population, I suspect that the Cypriot Killifish would move somewhere in the region of Vulnerable / Endangered. This classification would help generate far more support for the Cypriot Killifish and give an accurate depiction of its true conservation requirements.
One of the questions raised by S. Zogaris & S. Gucel in their blog report was the taxonomy of the Cypriot Aphanius, in particular the fish they found at the Glapsides Lagoon and whether they are an evolutionary relic worthy of their own taxonomic identity. The specimens myself and Christodoulos Parmatzias found at the Akrotiri site certainly display some unique phenotypical traits. This was also confirmed by ichthyologist Heiko Bleher who agrees that they are not only unique but “very different from other ‘fasciatus‘ populations”. I have sent preserved specimens away for DNA sequencing and will receive further information in due time but sooner to arrive I suspect, will be the DNA analysis results conducted by the Hellenic Centre for Marine Research. Hopefully we will get some results which can help this species not only survive, but thrive on the island of Cyprus and not become another red blotch on a distribution map.
Male Aphanius cf fasciatus (Akrotiri)
Female Aphanius cf fasciatus (Akrotiri)
In 2014 Myself and Christodoulos returned to Akrotiri to sample some other sites.
Read more about our second trip here
Images: C. Englezou © C. Parma © S. Zogaris © IUCN Redlist ©