The First Data on the Biology of Anatolichthys meridionalis (Actinopterygii, Aphaniidae): an Endemic and Endangered Fish of Turkey (Dalaman River Basin)

Species belonging to the Aphaniidae, extant as well as fossil, are widel distributed along the late-period Tethys Sea coast lines. Among the mentioned genera, Anatolichthys is the genus that includes the 13 species. Anatolia has been a center in the diversity of Anatolichthys. The study is one of the first studies on the growth of the species. On this occasion, in study, it was aimed to examine the growth parameters of the Anatolichthys meridionalis Akşiray, 1948 population, which is an endemic and endangered species in Anatolia. The population structure of endemic species Anatolichthys meridionalis in Gökpınar Spring (Dalaman River basin-Turkey) (37.34° N, 29.44° E) was studied, using 108 fish in October 2019 and September 2020. The growth and reproductive characteristics of A. meridionalis were examined in the study. Males made up 42.59%, females 57.41% of the population. The length-weight relationship and Von Bertalanffy growth equation were W = 0.0112L ^3.4638, R ² = 0.9793, L _t = 22.97 (1 - e^{-0.0304 (t+2.834)}), respectively. Average growth performance and condition factor are calculated as 1.21 and 1.84, respectively. The gonadosomatic index was found in a maximum value (12.742%) in July and a minimum value (0.545%) in January. Reproduction time was found to be in between of July and September. The mean fecundity and mean egg diameter were found as 147.94 ± 28.03 number/individual/year and 1.35 ± 0.04 mm, respectively. The first maturation was found to be at age I. First maturity length (L _m) was estimated at 23.95 mm for females and 22.04 mm for males. Although the study shows that the species has no problem in finding food and is a population with a wide age range, the presence of invasive species in the habitat, the habitat is directly affected by pollution from agricultural activities, water is drawn by pumps for agricultural activities, and it is narrowly distributed and endangered species, A. meridionalis and its habitat Gökpınar Spring should be protected.

Turcichondrostoma, a new genus for the Leuciscidae (Teleostei: Cypriniformes) from Southwestern Anatolia

Turcichondrostoma, a new genus, from the Southwestern Anatolia is distinguished by having fewer gill rakers on first gill arch and morphologies of premaxilla and dentary bones. In addition, as a result of the phylogenetic analyses based on combine data set (mtDNA COI + Cytb) sequences (1706 bp.), Turcichondrostoma genus was recovered with high posterior probability value (BI PP:1.0) and strong-supported bootstrap value (ML BP: 100%) among the former Chondrostoma groups. Also, high K2P mean genetic distance values (more than 7.84%) differentiated genus Turcichondrostoma from the other genera of former Chondrostoma group. The results of both morphological-osteological and molecular analyses are congruent with each other. The results of this study revealed that the genus Turcichondrostoma is easily distinguished from the genera in Chondrostoma group.

Chondrostoma smyrnae, a new nase from the Tahtalı reservoir drainage in the Aegean Sea basin (Teleostei, Leuciscidae)

Chondrostoma smyrnae, a new species, from the Tahtalı reservoir drainage is distinguished by having a slightly arched lower jaw with a well-developed keratinised edge, a deep and cylindric body, a complete lateral line with 47–52+1 total scales, 8–9 scale rows between the lateral line and the dorsal-fin origin, 4 scale rows between the lateral line and the pelvic fin-origin, and 19–23 gill rakers on the first gill arch. Moreover, molecular analyses using full cyt b (1141 bp) and partial coI (652 bp) sequences of the mitochondrial genome from specimens of the new species, C. smyrnae and specimens belonging to other Chondrostoma species from central and western Anatolia demonstrated that the C. smyrnae is easily differentiated by their high pairwise genetic distances of cyt b and coI data set (>2.20 and 1.03%, respectively) and by their position in the phylogenetic trees obtained through Maximum Likelihood (ML) methodology.

Barbus xanthos, a new barbel from the Southern Aegean basin (Teleostei: Cyprinidae)

Barbus xanthos, a new species, is described from the Eşen, Dalaman, Tersakan and Büyük Menderes rivers in south-western Anatolia. It differs from other Barbus species in the adjacent basins by having 53-60 lateral line scales, a weakly ossified last unbranched dorsal-fin ray (about 33-50%), numerous small irregular-shaped black or dark-brown spots smaller than scales, often forming large, black or dark-brown blotches on back and flank in juveniles and adults, and a straight or slightly convex posterior dorsal-fin margin. B. xanthos differs from its most closely related congener, B. pergamonensis, by nine nucleotide substitution sites in the mitochondrial DNA cytochrome oxidase I barcode region.

Description of a new species of Hemigrammocapoeta (Teleostei: Cyprinidae) from Lake Işıklı, Turkey

Hemigrammocapoeta menderesensis is distinguished from all other species of Hemigrammocapoeta in Anatolia by the following combination of characters (none unique to the species): lateral line incomplete; 6-17 perforated scales and 36-41 +1-2 scales in lateral series; 7½-8½ scale rows between lateral line and dorsal-fin origin, 3-4 scale rows between lateral series and anal-fin origin; dorsal fin commonly with 7½ branched rays; anal fin with 5½ branched rays; 15-17 gill rakers on the first brachial arch; pharyngeal teeth 2.4.5-5.3.3; mouth small, subterminal, horseshoe shaped and without barbel; lips developed and somewhat fleshy; upper lip not covering nostril gape; lower lip with two lateral lobes and median pad; lateral lobes smaller and shorter than half width of median pad; numerous papillae on lower and upper lips.