Fishes in the desert: mitochondrial variation and phylogeography of Danakilia (Actinopterygii: Cichlidae) and Aphanius (Actinopterygii: Cyprinodontidae) in the Danakil Depression of northeastern Africa

Abstract

The Danakil Depression in northeastern Africa represents one of the harshest arid environments on Earth, yet two genera of fishes, Danakilia (Cichlidae) and Aphanius (Cyprinodontidae), share its sparse aquatic habitats. The evolutionary history of these fishes is investigated here in the context of genetic, geological and paleoenvironmental information. We collected samples from seven sites and assessed phylogeographic relationships using concatenated COI and cytb mtDNA genes. Danakilia morphospecies show low differentiation at mitochondrial markers, but variation is partitioned between a northern cluster containing D. dinicolai plus three undescribed riverine populations, and a southern cluster including two creek populations of D. franchettii separated by the hypersaline waters of Lake Afrera. Aphanius displayed four genetically distinct clades (A. stiassnyae in Lake Afrera; one distributed across the entire area; one in Lake Abaeded; and one in the Shukoray River), but without clear large-scale geographic structure. However, Danakil Aphanius are clearly differentiated from A. dispar sensu stricto from the Sinai Peninsula. Geological evidence suggests that after the Late Pleistocene closure of the Danakil-Red Sea connection, increased post-glacial groundwater availability caused the formation of a brackish paleo-lake flooding the entire region below the -50 m contour. Fish populations previously isolated in coastal oases during glaciation were able to mix in the paleo-lake. Subsequently, in a more arid phase starting ∼7300 BP, paleo-lake regression isolated fishes in separate drainages, triggering their still ongoing diversification.

Diversity and structure of fragmented populations of a threatened endemic cyprinodontid (Aphanius sophiae) inferred from genetics and otolith morphology: Implications for conservation and management

“…The Cyt b gene (mtDNA) showed low level of genetic variation, and only 4.12% of the identified sites were variable and 2.42% were parsimony informative. Such degree of genetic variability and nucleotide diversity (π = 0.0061) are lower or similar than those reported, using the same molecular genetic marker, for other threatened freshwater fish species with larger geographic ranges (e.g., Buonerba et al, 2015), cyprinodontid (e.g., Marchio & Piller, 2013), and Aphanius (e.g., Chiozzi et al, 2018;González et al, 2017…”

DNA barcoding and species delimitation of the Old World tooth-carps, family Aphaniidae Hoedeman, 1949 (Teleostei: Cyprinodontiformes)

“…For obtaining a reliable outcome, a total of 211 COI sequences [10,67,[85][86][87][88] from 28 Aphanius species were retrieved from GenBank and included in the phylogenetic analyses ( Table 2). The goby killifish, Aphyosemion franzwerneri (Accession number: EF417044) was used as an outgroup.…”

“…The Near East, especially Iran and Turkey host the largest number of species [11,16,40,44,66]. As mentioned above, numerous authors have so far studied different aspects of these fishes, including the phenotypic variation, embryology, allopatric distribution, species diversity, historical zoogeography, evolutionary history and phylogenetic relationships [11,23,28,[67][68][69][70][71][72][73][74][75][76][77][78][79]. Particularly, significant progress has been made during the past decade to reconstruct the phylogenetic relationships of Aphanius species in the Near East [10, 15, 19-22, 40, 44, 46-48, 50, 51, 80-82].…”

Systematics and historical biogeography of theAphanius disparspecies group (Teleostei: Aphaniidae) and description of a new species from Southern Iran

“…Species of Aphanius are well known for their remarkable capacity to adapt to adverse ecological conditions and evolve into new species when populations become isolated. This has made them particularly attractive as model species for biologists, and many researchers have studied their phenotypic variation, diversity, zoogeography, and phylogenetic relationships (e.g., Chiozzi et al., ; Ferrito, Mannino, Pappalardo, & Tigano, ; Ferrito et al., ; Hrbek & Meyer, ; Parenti, ; Tigano, Ferrito, & Nicosia, 1999; Tigano et al, ; Villwock, ; Wildekamp et al., ). Over the past decade, significant progress has also been made in elucidating the phylogeny of Aphanius in the Near East, with a strong focus on populations in Iran (Coad, ; Esmaeili, Teimori, Gholami, & Reichenbacher, ; Esmaeili et al., ; Esmaeili, Teimori, Sayyadzadeh, Masoudi, & Reichenbacher, ; Gholami et al., ; Gholami, Esmaeili, Erpenbeck, & Reichenbacher, ; Gholami, Esmaeili, & Reichenbacher, ; Gholami, Teimori, Esmaeili, Schulz‐Mirbach, & Reichenbacher, ; Hrbek et al., ; Masoudi et al., ; Teimori, Esmaeili, et al., ; Teimori, Schulz‐Mirbach, et al., ; Teimori, Jawad, Al‐Kharusi, Al‐Mamry, & Reichenbacher, 2012; Teimori et al, ).…”

“…However, the only studies that have yet considered “ A. dispar ” based on molecular genetic analyses are those of Hrbek and Meyer (), Chiozzi et al. (), and Freyhof et al. ().…”