Latest Articles from Zoosystematics and Evolution Latest 3 Articles from Zoosystematics and Evolution https://zse.pensoft.net/ Thu, 28 Mar 2024 16:17:25 +0200 Pensoft FeedCreator https://zse.pensoft.net/i/logo.jpg Latest Articles from Zoosystematics and Evolution https://zse.pensoft.net/ Two new Oxynoemacheilus species in western Anatolia (Teleostei, Nemacheilidae) https://zse.pensoft.net/article/102575/ Zoosystematics and Evolution 99(2): 439-455

DOI: 10.3897/zse.99.102575

Authors: Davut Turan, Sadi Aksu, Gökhan Kalayci

Abstract: Oxynoemacheilus sakaryaensis sp. nov., is restricted to the Sakarya River basin, and O. melenicus sp. nov., is distributed in both the Sakarya River and Büyükmelen Stream. Oxynoemacheilus sakaryaensis is distinguished by having a flank plain or with numerous irregularly shaped pale brownish bars and a caudal-peduncle depth 2.8–3.2 times in its length. Oxynoemacheilus melenicus is distinguished by having a flank with 10–13 irregular shaped brownish bars or blotches and the caudal peduncle depth 1.9–2.8 times in its length. Oxynoemacheilus banarescui, O. samanticus, O. simavicus, O. fatsaensis, O. sakaryaensis, and O. melenicus are valid, which belong to the O. bergianus species group. O. melenicus and O. sakaryaensis were differentiated from all other Oxynoemacheilus species in western Anatolia by two diagnostic and unique nucleotide substitution sites in the COI barcoding region. Also, species delineation tests (ABGD, GMYC, ASAP) and phylogenetic analyses support the validity of O. melenicus and O. sakaryaensis as distinct species.

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Research Article Wed, 4 Oct 2023 19:06:47 +0300
A new freshwater amphipod (Amphipoda, Gammaridae), Gammarus tumaf sp. nov. from the Gökgöl Cave, Türkiye https://zse.pensoft.net/article/89957/ Zoosystematics and Evolution 99(1): 15-27

DOI: 10.3897/zse.99.89957

Authors: Murat Özbek, İsmail Aksu, Hazel Baytaşoğlu

Abstract: A new amphipod species belonging to the genus Gammarus is described from the Gökgöl Cave, Zonguldak Province, Türkiye. The newly-identified species is relatively small (13 mm) and is a member of the Gammarus pulex-group by the presence of numerous long setae along the posterior margins of pereopods 3 and 4. The specimens were sampled from a shallow pond located in the dark zone (about 1 km inside the entrance) of the cave. Minute eyes, setose (both peduncle and flagellar segments) second antenna, slightly swollen flagellar segments of the second antenna, setose pereopods 3 and 4 and relatively short endopod/exopod ratio of the third uropod are the character combination of the newly-identified species in addition to lacking body pigmentation. The molecular phylogeny, based on the concatenated dataset (28S+COI, 1495 bp) indicated that the new species was resolved from the other Gammarus species by high bootstrap (NJ: 100, ML: 100). In addition to Gammarus tumaf sp. nov., mtDNA COI and nuclear DNA 28S gene data of Gammarus baysali Özbek et al., 2013 were recorded for the first time. The newly-identified species was well-differentiated from the genetically closest species, G. baysali, with genetic distance of 12.22% and 0.55% for the COI and 28S genes, respectively. Detailed descriptions and drawings of the extremities of the holotype male were given and the morphology of the newly-identified species is compared with its relatives.

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Research Article Fri, 6 Jan 2023 17:24:38 +0200
The discovery of a microbialite-associated freshwater fish in the world’s largest saline soda lake, Lake Van (Turkey) https://zse.pensoft.net/article/62120/ Zoosystematics and Evolution 97(1): 181-189

DOI: 10.3897/zse.97.62120

Authors: Mustafa Akkuş, Mustafa Sarı, F. Güler Ekmekçi, Baran Yoğurtçuoğlu

Abstract: Lake Van is the largest saline soda lake in the world and one of the world’s few endorheic lakes of greater than 3,000 km2 surface area. Despite its huge size, no fish species have so far been known to permanently occur in this lake due to its extreme environmental conditions. Here, we report the discovery of a fish population that permanently inhabits some of the unique microbialites of the lake, at a maximum depth of 13 m and about 500 m offshore. We tested whether this is an undescribed species or a new occurrence of a known species. A molecular and morphological examination showed that the newly discovered fish represents an isolated population of Oxynoemacheilus ercisianus, the only nemacheilid loach native to the freshwater tributaries of the Lake Van endorheic basin. Our further hypotheses on the prediction that (a) stream fishes would have a more anterior placement of fins than lake fishes were supported; but, that (b) stream fishes would be more slender bodied than their lake conspecifics was not supported. The lake dwelling population also shows very small sequence divergence (0.5% K2P distance) to its stream dwelling conspecific in the mtDNA-COI barcode region. The notable morphological difference with minute molecular divergence implies that the newly discovered population might have lost its link to freshwater during desiccation and transgressional phases of the Lake Van, and has adapted to a life on the microbialites.

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Research Article Tue, 16 Mar 2021 10:29:23 +0200