Fish milt quality and major factors influencing the milt quality parameters: A review

In commercial fish production, the evaluation of milt quality is essential in order to increase the efficiency of artificial fertilization. Numerous studies have demonstrated that qualitative parameters of milt (i.e. seminal fluid composition, spermatozoa motility and sperm production) could be influence by several factors including biological characteristics of brooders (age, weight and length), rearing conditions of brooders (temperature, photoperiod, nourishment, undesirable components and animal welfare and health), artificial induction of spawning, spawning season (repeated milt collection and spermiation time) and post stripping factors (chemical properties of diluents and short-term and long-term storage of milt). In the present paper, we review the roles of these factors on quality of milt fish. On the whole understanding of the factors that affect milt quality could be useful for adjustment and efficient management of these factors in order to obtain good milt for fertilization.Keywords: Fish production, milt quality, artificial fertilizatio

Acute toxicity and behavioral changes of Caspian kutum (Rutilus frisii Kutum Kamensky, 1991) and Caspian roach (Rutilus rutilus caspicus Jakowlew, 1870) exposed to the fungicide hinosan

Pesticides are used in agriculture to control pest and protect human health and animals. Excessive use of pesticides caused risk for human health and threated non-target organisms, polluted water, soil and air. Hinosan is a component of organophosphate pesticide which is used as a fungicide in agricultural fields. In the study, lethal concentration (LC50) of Hinosan was calculated for Rutilus frisii kutum and Rutilus rutilus caspicus with a mean weight of 3 ± 1 g [mean ± SD]. The experiment were carried out in static condition and based on instructions of O.E.C.D in four days under controlled water physicochemical factors with pH = 7 to 8.5, dissolved oxygen = 200 mg L-1 (CaCO3) and temperature = 20 ± 1°C. Fishes were acclimatized in 70x40x30 cm aquarium for 10 days. Five treated aquariums with concentration ranges 1, 2, 4, 8, 16 ppm of hinosan (Technical 95 Edifenphos) with one control group (no toxic concentration), were performed. Data were analysed using the probit analysis. LC1, LC10, LC30, LC50, LC70, LC90 and LC99 were calculated in 24, 48, 72 and 96 h. Our results indicate that LC50 96 h hinosan for R. frisii Kutum and R. rutilus caspicus were obtained 3.61 and 2.88 ppm, respectively. These findings suggest that hinosan is medium toxicity for these two species. Clinical symptoms including irregular protrusion of the eyes and irregular swimming were observed.Key words: Organophosphore, hinosan, Rutilus frisii kutum, Rutilus rutilus caspicus, LC50, pollution

Effects of letrozole, non-steroidal aromatase inhibitor, on serum sex steroid levels, oocyte diameter and gonadosomatic index (GSI) in rainbow trout (Oncorhynchus mykiss)

The objective of this study was to contribute to investigate the efficacy of letrozole, a potent non-steroidal aromatase inhibitor, on serum sex steroid levels and oocyte growth in rainbow trout females. Serum steroid levels were measured using an indirect enzyme-linked immunosorbent assay (ELISA) before and 22 days after an initial injection with 1, 2.5 mg kg^-1 and subsequent weekly injection with 2.5 mg kg^-1 letrozole. After the last blood collection, gonad tissues were removed and oocyte diameter and GSI were determined. In all groups treated with letrozole, serum 17β-esteradiol levels (E2) decreased significantly and inversely serum 17α-20ß dihydroxy-4 pregnen-3-one (17α-20ß-P), testosterone (T) levels increased significantly from 6 to 96 h after injection (p<0.05). The lowest E2 levels, oocyte diameter and GSI were measured in the group treated weekly with 2.5 mg kg^-1 letrozole (p<0.05). This study demonstrates that letrozole has the potential to interfere in the synthesis of endogenous estrogens from androgens and delay gonadal development

Effect of different salinity on ions, osmolarity, water concentration of body tissue, gill chloride cells and mortality percentage of juveniles of Caspian roach (Rutilus frisii kutum Kamensky 1901)

Changes of ions (Na+, Ca, K+), osmolarity and water concentration of body tissue, size and number of gill chloride cells as well as mortality percentage of the juveniles Caspian roaches in weight groups of 0.2, 0.5 & 1g water satiny stress were studied. The salinities tested were 0 (fresh water), 7, 12.5 & 16 g/lit and the assessments were completed 0, 12, 24, 48 & 72 hours after exposure. Results showed that ions and osmolarity of juveniles weighting 0.2 & 0.5g in salinities of 0 up to 12.5g/lit increased significantly during the first 12 hours (P'<0.05). These values then showed down were trend to the values recorded for fresh water. Water concentration of body tissue reached the minimum mean value in 12 hours (P<0.05) in salinity of 12.5 g/lit and then showed upward trend to the value obtained for freshwater. Ions and osmolarity of body tissue of the juveniles increased and water concentration of body tissue decreased significant after the first 12 hours of transferring into salinity of 16g/lit (P<0.05). Weight changes in juveniles of 1g in salinities of 0 up to 16g/lit was similar to juveniles of 0.2 & 0.5g in salinities of 0 up to 12.5gllit and the maximum mean values of ions and osmolarity and the minimum value of water concentration body tissue in 16g/lit salinity in hour 12 (P<0.05). Size and number of gill chloride cells of juveniles weighting 0.2 & 0.5g in salinities of 0 up to 12.5g/lit increased significantly during the first 12 hours of exposure (P<0.05) and reached the maximum mean values in 12.5g/lit salinity 12 & 24 hours after exposure, respectively (P<0.05) and showed invisible changes up to the end of the test. Size and number of chloride cells of the juveniles increased after the first 12 hours of transferring into salinity of 16g/lit (P<0.05). Changes of the indices in juveniles weighting 1gin salinities of 0 up to 16g/lit was similar to juveniles of 0.2 & 0.5g kept in salinities of 0 up to 12.5gtlit and the maximum values was in 12 and 24 hours after exposure, respectively (P<0.05). Ions and osmolarity of body tissue and size and number of chloride cells increased significantly with increase of salinity and weight and water salinity and water concentration of body tissue decreased significantly with increase in water salinity and increased in fish weight (P<0.05). Juveniles weighting 0.2 up to 1g showed no mortality in salinities of 0 & 7g/lit during t- test. Mortality of the juveniles weighting 0.2, 0.5 and 1g/1it increased during the first 12 hours and became constant to the end of the test. Mortality of juveniles weighting 0.2 & 0.5g in salinity of 16g/lit was similar to that of the juveniles weighting 0.2 & 0.5g in salinity of 12.5g/lit. Mortality of the juveniles increased significantly with increase of salinity and decreased with increase of weight (P<0.05)

Effects of cadmium on spermatogonia, spermatocytes and sperm motility of Caspian kutum, Rutilus frisii kutum

Cadmium is one the common heavy metals that usually enters the Caspian Sea and the riverine ecosystems. Effect of Cadmium on spermatogenesis in Caspian kutum and motility of spermatozoa were studied. At first, kutum testis was exposed to Cadmium using in vitro testis culture in 10-5, 10-6 and 10-7 M concentration of CdCl2 solution for 3 and 6 days and in the second experiment, spermatozoa motility was evaluated after exposure to 0, 0.01, 0.1, 1, 10, 100 and 1000 mg/l of CdCl2 solutions. With the increase in Cadmium concentration, due to the reclining effect of Cadmium on spermatogenesis, the number of spermatocytes and size of germ cells decreased significantly. Motility of spermatozoa decreased significantly with increasing Cadmium concentration and its motility stopped in 1000 mg/l. Reduction in quality and quantity of germ cells could impair offspring production and recline their viability and thus posing threats on valuable kutums stocks

Preparation and anatomical distribution study of 67Ga-alginic acid nanoparticles for SPECT purposes in rainbow trout (Oncorhynchus mykiss)

Ergosan contains 1% alginic acid extracted from two brown sea weeds. Little is known about the target organs and anatomical distribution of Ergosan (alginic acid) in fi sh. Therefore, feasibility of developing alginic acid nanoparticles to detect target organ in rainbow trout is interesting. To make nanoparticles, Ergosan extract (alginic acid) was irradiated at 30 kGy in a cobalt-60 irradiator and characterized by transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). Results from TEM images showed that particle sizes of irradiated alginic acid ranged from 30 to 70 nm. The FTIR results indicated that gamma irradiation had no signifi cant infl uence on the basic structure of alginic acid. Later, alginic acid nanoparticles were successively labelled with 67Ga-gallium chloride. The biodistribution of irradiated Ergosan in normal rainbow trout showed highest uptake in intestine and kidney and then in liver and kidney at 4- and 24-h post injection, respectively. Single-photon emission computed tomography (SPECT) images also demonstrated target specifi c binding of the tracer at 4- and 24-h post injection. In conclusion, the feed supplemented with alginic acid nanoparticles enhanced SPECT images of gastrointestinal morphology and immunity system in normal rainbow trout