IRANIAN JOURNAL OF ICHTHYOLOGY
Year:2016 | Volume:3 | Issue:1 |Papers Count:7

The systematics, morphology, phylogeny, distribution, biology, economic importance and conservation of the Fars tooth-carp, Aphanius farsicus of Iran are described, the species is illustrated, and a bibliography on this endemic, critically endangered species is provided. Iran and central Anatolia show the highest diversity of Aphanius, and 14 extant (including Aphanius farsicus, an endemic species in the endorheic Lake Maharlu basin, South-western Iran) and one fossil species are known to occur in Iran based on data derived from fish morphometry and meristics, otoliths, scales and mtDNA sequences. Human-induced disturbance or anthropogenic activities, including hydrological alteration, introduction of exotic species, intensive aquaculture industry, water pollution, rapid sedimentation, natural disturbance (climate change and drought) and also limited distribution, have forced Aphanius farsicus populations to the edge of extinction. Aphanius farsicus can benefit from a combination of reintroduction, assisted colonization and capture release which potentially increase success rate of a conservation management plan. Encouraging the local communities, NGOs and media to involve voluntarily in longterm conservation programs is highly recommended.

The blue tilapia, Oreochromis aureus (Steindachner, 1864) is recorded for the first time from the Arvand and Karun River drainages in Khuzestan province, Iran. This species is the second tilapia fish, recorded and confirmed by specimens from natural water bodies of Iran. The relative abundance and location records of the observed blue tilapia are presented. As tilapia species have high resistance for different environmental conditions and can easily propagate in new habitats, thus its monitoring is highly recommended.

The convict cichlid, Amatitlania nigrofasciata (Gü nther, 1867) is recorded for the first time from Soleymaniyeh spring, Namak Lake basin in central Iran, the second record of this species from the country. Amatitlania nigrofasciata has been probably released into the spring, as an aquarium fish by local people, but has been now possibly established in this water body. The monitoring of this exotic fish is highly recommended.

The present study investigates and reports the effects of sudden salinity changes on short-term hematological and biochemical responses in Walton's mudskipper, Periophthalmus waltoni. For this purpose, mudskippers caught from coastal area of Persian Gulf (Bandar Khamir, Hormozgan Province, Iran) were acclimated and fed with frozen blood worms (Chironomus) for one month prior to the start of experiments. After acclimation, groups of 15 individuals were fully submerged in either dechlorinated tap water (fresh water; Group A), 50% seawater (SW) (17‰ salinity; Group B), or 100% SW (35‰ salinity; Group C) during a period of 24 hours. Fish which were free to be in or out of 50% SW served as controls. Statistical analysis showed a significant influence of salinity levels on erythrocyte, haemoglobin, haematocrit, leucocytes, lymphocytes, neutrophils, monocytes and on all biochemical parameters tested during the study. It seems that the changes recorded in haematological and biochemical parameters were the best strategy that the Walton's mudskipper has to adapt itself to an environment with different salinity levels.

We examined 272 specimens of Paracobitis malapterura throughout the spawning season (February to July, 2014) from Qom River (Central Iran) to describe their age, growth, and reproduction. Sex ratio was 1: 6. 1 in favor of females. Among the examined specimens, the maximum age was 3+ years. The specimens ranged 35-120mm in total length and 0. 38-9. 58g in total weight. Length-weight relationship was estimated as W=1E-05TL2. 94, W=2E-05TL2. 73, and W=1E-05TL2. 92 for females, males and combined sexes, respectively. The growth type was isometric for females and sexes combined and negative allometric for males. Based on the gonado-somatic index values, spawning occurs between late February and late April. The highest mean GSI was 1. 9, and 13. 85 for males and females, respectively in April. The absolute fecundity ranged from 164 to 793 with a mean of 353. 3 eggs. Fecundity was positively correlated with fish size (length and weight).

An 8-week feeding trial was conducted using a flow-through system to determine the effect of different levels of dietary vitamin premix on growth, carcass, hematological and biochemical indices of juvenile rainbow trout. Practical diets with six levels (0. 00, 0. 25, 0. 50, 0. 75, 1. 00 and 1. 25%) of dietary vitamin premix were fed to rainbow trout juveniles (mean initial weight 26. 3± 2. 9g) at 3 replicates. Growth indices containing final weight, weight gain, body weight increase, feed conversion ratio, specific growth rate, condition factor and hepatosomatic index were not affected by dietary treatments. No mortality or deficiency signs were observed during the experiment. There was no significant difference in carcass proximate compositions. Hematological indices, including hematocrit, hemoglobin and the number of red blood cells were affected by dietary treatments, but the number of white blood cells was not affected. Biochemical indices containing cholesterol, total protein, and peroxidase did not differ significantly in fish fed the different diets, but significant difference was observed in triglyceride and alkaline phosphatase levels. Stress indices including cortisol, glucose and lactate levels showed significant difference among the treatments. Regarding to the obtained results, both nonsupplementation and excess supplementation of vitamin premix in the diet have some negative effects on rainbow trout. Thus, the appropriate level of vitamin premix should be used in the diets of this species.

The systematics, morphology, distribution, biology, economic importance and conservation of the snakehead (Channa gachua) of Iran are described, the species is illustrated, and a bibliography on this fish is provided. The single species is distributed in southeastern Iran.