Following the Mangroves: diversification in the banded lampeye Aplocheilichthys spilauchen (Duméril, 1861) (Cyprinodontiformes: Procatopodidae) along the Atlantic coast of Africa

Abstract

Available ecological information, an extensive distributional range, conflicting osteological data, and a proposed early Miocene origin provide the impetus for the present study which investigates genetic structuring, biogeographic, and phylogenetic relationships within the Aplocheilichthys spilauchen lineage. Through the analysis of the mitochondrial gene COI, species delimitation methods (ABGD, GB, GMYC, bPTP) were applied, recognizing 6-7 OTUs with absolute pairwise genetic distances ranging between 8 and 22%. The onset of diversification is estimated to be within the middle Miocene and both dispersal and vicariance-shaped A. spilauchen diversity and distribution, as suggested by time-calibrated and ancestral range reconstruction (S-DIVA) analyses. We report for the first time, a pattern of diversification within a lineage of brackish water fish that is concordant with the historical distribution of coastal mangroves forests, shaped by a series of historical events that likely affected forest cover since the middle Miocene (e.g. major climate shifts and sealevel fluctuations, onset of the modern Congo River outlet, increased volcanism in the Cameroon Volcanic Line).

Spawning habits and embryonic development of the banded lampeye killifish Aplocheilichthys spilauchen (Duméril 1861) in ex situ fresh and brackish water environments

“…Aside from biocontrol, the work also opens a new discussion on the prospects of breeding the lampeye as baitfish for the Tuna Fishing Industry in Ghana given that the declined small pelagic stocks in country have rendered anchovies, Engraulis encrasicolus (Linnaeus 1758), the traditional baitfish for the industry, unavailable and alternatives are currently being sought. Finally, our research complements the work of others such as Bragança and Costa (2019) and Bragança et al (2021) in promoting research on African lampeyes.…”

“…It is important to emphasize that for future breeding programs and introduction of A. spilauchen , local populations should be used since reports indicate there are large genetic distances between different populations. Populations from Ghana to the west split from eastern and southern populations about 15 million years ago and are genetically deeply separated from all other populations along the African coast, where also several deeply separated metapopulations occur with genetic differences that are four to 11 times higher than the heuristic threshold of 2%–3% for teleostean conspecifics (Bragança et al ., 2021). Aside from biocontrol, the work also opens a new discussion on the prospects of breeding the lampeye as baitfish for the Tuna Fishing Industry in Ghana given that the declined small pelagic stocks in country have rendered anchovies, Engraulis encrasicolus (Linnaeus 1758), the traditional baitfish for the industry, unavailable and alternatives are currently being sought.…”

“…Finally, our research complements the work of others such as Bragança and Costa (2019) and Bragança et al . (2021) in promoting research on African lampeyes.…”

“…One such killifish species with wide geographical distribution along the West Coast of Africa (Wildekamp, 1995) that is being explored in Ghana for its mosquito biocontrol prospects is the banded lampeye, Aplocheilichthys spilauchen (Duméril 1861), the first described killifish from Africa (Wildekamp et al ., 1986). A recent study on the populations of A. spilauchen along the West African coast showed a high genetic divergence, suggesting that the populations probably correspond to different subspecies (Bragança et al ., 2021), which reinforces the need to use native killifishes for biocontrol rather than non‐native species. A previous study by Okyere (2012) on the food habits of a A. spilauchen population from coastal wetland pools in Ghana indicated that the fish could be a potential candidate for mosquito control due to its predatory habits on insects such as chironomid (midge) larvae.…”

Phylogenomics and Morphology of the African Fish Genus Brycinus with Revalidation of Brachyalestes and Description of a New Species from the Congo Basin (Teleostei: Alestidae)

“…10). Following the climatic optimum warm/ humid phase of the Middle Miocene, the second half of the Miocene experienced a global cooling trend accompanied by the expansion of arid biomes, including the formation of the Sahara Desert, followed by an extended period of climatic instability (Zachos et al, 2001;Brennan and Keogh, 2018;Braganc ¸a et al, 2021). While the geo-hydrological history of the central Congo basin is poorly understood, dynamic climatic and hydrological landscapes during the Late Miocene to Early Pliocene likely facilitated widespread allopatric speciation throughout the region.…”