Iranian Journal of Ichthyology
Volume:5 Issue: 3, Sep 2018

This study was conducted to determine some biological aspects of the tiger tooth croaker Otolithes ruber in the coastal waters of the northern Makran/Oman Sea. Monthly total length frequency data of O. ruber were collected by bottom gill-net and bottom trawl from August 2016 to August 2017. ELEFAN-I method in the software package FISAT-II was used to analyze of the length frequency data. The total length and weight relationship demonstrated that growth in this species is negative allometric. The asymptotic total length (TL∞) was estimated as 60 and 65cm for males and females, respectively. The growth parameter K was calculated as 0.43 y-1 for males and 0.40 y-1 for females. The total mortality, natural mortality and fishing mortality rates were estimated as 1.85, 0.83 and 1.02 for males and 1.37, 0.77 and 0.60 for females. The exploitation rates were estimated at 0.44 for males and 0.55 for females. The sex ratio revealed that it was not a constant 1:1 throughout the year, with 58 % for females. The Gonado-Somatic Index (GSI) showed upswing trend from January to June, and the maximum GSI was 7.1±0.6 in April. The recorded result showed that the tiger tooth croaker can spawn all year round and have a spawning peak from April to June (spring season). The Lm50% was estimated at 43.3cm of total length.

The feeding characteristics of Aphanius isfahanensis in the Zayandeh River of Isfahan Province were studied by collecting 440 specimens (220 males and 220 females) from July 2016 to May 2017. The specimens were anesthetized in 1% clove oil, fixed in 10% buffered formalin and transferred to the laboratory. The average condition factor for males was 1.7, for female 1.26 and showed significant difference between different months in both sexes (P<0.05). The average length and weight for all specimens were 38.57±5.24mm and 1.00±0.41g, respectively. The average length of gut (RLG) for all fish was 0.54±0.17 during the year. The mean RLG in different length classes showed significant differences (P<0.05). The highest Gastrosomatic Index value was in July (0.05) and the lowest in August (0.03) and showed significant differences in different months (P<0.05). A total of 181 empty stomachs were observed amongst the 440 fish and there were significant differences in different months (P<0.05). Therefore, it can be concluded that this is a carnivorous fish (mainly aquatic insect larvae) with a modest feeding throughout the year

The present study provides a checklist of the family Blenniidae from intertidal habitats along the Iranian coasts of Persian Gulf and Makran Sea. This research carried out during the years 2013-2018 at nine stations (Dayyer, Haale, Bostanou, Bandar Lenge, Qeshm, Gataan, Jask, Gugsar and Chabahar) with almost rocky profile covering whole distribution range of the family. A total of 15 species including 11 species from collection sites and four species from previous works are listed here: Alticus kirkii, Antennablennius adenensis, A. bifilum, A. variopunctatus, Istiblennius edentulus, I. lineatus, I. pox, I. spilotus, Parablennius cornutus, P. opercularis, P. pilicornis and Scartella emarginata (subfamily Salariinae); Omobranchus fasciolatus, O. mekranensis and O. punctatus (subfamily Blenniinae). The most diverse genus is Istiblennius (four species, 26.6%) followed by Antennablennius, Parablennius and Omobranchus (each with three species, 20%), Alticus and Scartella (each with one species, 6.6%). All reported species, except the endemic Makran comb-tooth blenny, Omobranchus mekranensis, Vulnerable) are considered as Least Concern (LC).

The Dalmatian barbelgudgeon, Aulopyge huegelii is a stenoendemic fish species restricted to the area of west Bosnia and part of Dalmatia. Its global IUCN species status is “endangered (EN)” according to the “B1ab (iii, v)” criterion. There are not enough reliable sources containing data on this species, particularly in the recent period. As primarily a groundwater fish, it was exceptionally well adapted to environmental conditions in the Buško Blato reservoir. Based on the recent findings, the status of this species has changed over the past several years. The main objective of this study was to characterise and determine the current status of the monotype species A. huegelii from the Buško Blato reservoir, through the analysis of its selected morphological and ecological features. During field research, we have gathered 88 individuals of A. huegelii, at just four neighbouring sites. A significant decrease in its population number is evident in comparison to previous studies. The results have shown its retreat into a small part of the reservoir which is connected with the groundwater system as its primary habitat, in order to escape from predators: the four new allochthone species in this ecosystem. Comparing the results with previous studies, it could be concluded that the Dalmatian barbelgudgeon is “returning” to its original morphological form i.e. groundwater fish form. All this could in perspective have significant consequences on the survival of the population of this species in the Buško Blato reservoir.

A new species of nemacheilid fish, Oxynoemacheilus veyseli sp. n., is described from the upper Aras River drainage, Kars Province, Turkey. The species differs from its congeners in the Caspian Sea basin in the combination of the following characters: flank with a set of mid-lateral elongated, irregular-shaped dark brown blotches, sometimes fused, interrupted by lateral line; dorsum with three or four separated dark-brown roundish to elongated blotches predorsally and postdorsally; a deep and marked suborbital groove and many small unculi on rays of pectoral and dorsal-fin in male; small eye diameter (9.6-13.7 %HL); a short dorsal-fin base (10.1-13.3 %SL); 3-4 lateral and 3 central pores in supratemporal canal; deep body and caudal peduncle (17.3-19.4 and 10.2-11.4 %SL, respectively) and slightly emarginated caudal fin

The freshwater Prussian carp, Carassius gibelio (Bloch, 1782) is a cyprinid, known as a hazardous species for native fish communities. In the present study, some population parameters, including length-weight relationship (LWR), condition factor (KF), relation condition factor (Kn), age and growth of C. gibelio in the Azad dam, Kordestan Province, Iran were estimated. The LWR indicating a positive allometric growth pattern. The von Bertalanffy growth parameters were estimated as L∞=337mm, K=0.255 yr-1, t0=-0.21 yr. There was a significantly positive correlation between TL and KF (r2=0.89). The average of Kn was lower than 1 which suggested that the well-being of the fish was not good in the Azad dam region.

Introduction of alien parasitic nematodes to the wild fish species might result in a severe threat to native species biodiversity including native fish species and native parasitic fauna. In the present study, the invasive Asian nematode, Camallanus cotti (Nematoda: Camallanidae), has been reported for the first time in Giant Danio (Devario aequipinnatus) in the Cauvery river systems of Southern part of Western Ghats, India. The occurrence of this parasite in both aquarium-cultured fish as well as from the natural aquatic bodies dwelling fish is evident of the introduction of the alien organisms due to insufficient prophylactic measures during the transmission of non-native hosts between countries and also the spread of them by the anthropogenic introduction to natural systems.