Identification of different species of squids in Oman Sea (Iranian waters)

Identification of different species of oceanic and neritic squids in Iranian waters of Oman Sea was carried out from December 1996 to February 1997. The trawl surveys were conducted during a 12-months period. Fishing was also undertaken by Mid-water and bottom trawl for species confirmation purposes in deep (200-350m) and shallow (0-100m) waters to collect enough specimens that could be used for later species identification. The RN Ferdows-I was used for sampling with an approximate hauling speed of 3.0 knots. Three oegopsid species including Ancistrocheirus lesueuri, Liocranchia reinhardti, Sthenoteuthis oualaniensis and neritic squid, Loligo duvauceli were identified. Another loliginid squid different from Loligo duvauceli was also observed. A. lesueuri (Enoploteuthidae Family) and Liocranchia reinhardti (Cranchiidae Family) are here reported from this area for the first time. Neither was any report about these two families of oegopsid squids in Oman Sea nor Persian Gulf

Commercial catch management of spiny lobster, Panulirus homarus in the coastal waters of Sistan and Baluchestan Province

Management of commercial catch of the spiny lobster, Panulirus homarus Linnaeus, 1758; was studied in fishing season, from September to November 2001. P. homarus specimens were captured from different fishing sites of Ramin, Chabahar, Konarak, Puzm and west of Puzm. Carapace length and sex of specimens and presence of eggs and pleopods of females were considered. The latter factor was noticed to check of the eggs removed from pleopods. Fishing season takes about one and the half months. The maximum and minimum carapace length were observed in west of Puzm (80.04 + 9.02 mm) and puzm (76.46 6.66 mm), respectively. Minimum size limit specimens at different fishing sites were not significantly different, but frequency of them were more than years of 1999 and 2000, although fewer ovigerous females were caught. A better management of the lobster resources needs the collaboration on fishing, fisheries and research within the Iranian authorities, and also fisheries cooperation of the two neighboring countries

An exploration on the responsibility to social adequacy in adolescent learning environments affected by the type of design experience based on the biophilic attitude

What is considered as a serious concern in the contemporary urban system is the widening gap between man and natural systems. The extreme density of buildings has brought about interaction with technology instead of interaction with nature, and lack of interest in environmental concerns for the urbanite adolescents, which can lead to a serious crisis in the mental health of an adolescent due to being on the path of maturity. Many studies in the field of learning environments indicate the effectiveness of interaction with natural processes on the promotion of adolescents' social identity; therefore, creating a suitable environment for reducing social harm and acquiring social skills can be effective in reducing mental pressures. Background and Objectives: Researches have shown that adolescents' interaction with nature is effective in improving stress and promoting effective mental health, and also nature-based learning environments play an important role in improving adolescents' social identity. This study tries to improve the level of adolescents’ mental health by recognizing and analyzing biophilic approach patterns as a nature-based approach, along with acquiring related capabilities and skills in educational environments. In addition to the explanation of the patterns corresponding to the experiences of biophilic (bio-oriented) attitudes, the present study prioritizes the related environmental indicators to acquire the abilities (cognitive, behavioral, emotional, and motivational) of the adolescence period in the context of learning. Materials and Methods: The used method is applied in terms of purpose, and the study method is descriptive-analytical and survey in terms of nature. Data collection is based on the study of library resources, and in the field stage, it is based on the distribution of questionnaires and interviews; also, the SPSS software was used to analyze the data. The Chi-square test is used to examine the significance of the relationship between variables in the research hypotheses, and the Pearson test is used to examine the correlation of independent and dependent variables that indicates the establishment of a correlation between research variables, which shows that the accuracy between all variables is less than 0.05 and the correlation coefficient of all relations is positive. The correlation coefficient between all variables is above 0.6 that indicates the establishment of a positive and strong relationship between all of the variables. The Friedman test was used in order to prioritize the relationships and strategies, and the content validity method was used to determine the reliability of the measurement of the questionnaire’s validity; also, the Cronbach's alpha test was used to examine the reliability of the questionnaire in SPSS software. Results: There is a significant difference between the types of environmental experiences (direct experience of nature, the indirect experience of nature, and the experience of space and place) in order to establish a compatible interaction between adolescents and nature. Also, the experience of direct interaction between adolescents and cognitive competence acquisition has the greatest impact on the promotion of adolescents' mental health; subsequently, the indirect experience of nature with cognitive competence acquisition and experience of space and place with behavioral competence acquisition have the greatest impact on the promotion of adolescents' mental health. According to the obtained information, social competencies are prioritized through biophilic design experiences. Conclusion: The results indicate that design experiences in the context of learning according to the biophilic approach can meet the psychological needs of the adolescent period, because of the deep multifaceted relationship with nature. Providing solutions following the patterns of this approach in nature-based learning environments can provide the conditions for achieving social adequacy and promoting adolescents’ mental health.   ===================================================================================== COPYRIGHTS  ©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

Study on nutrition requirements and effect of different diets on gonadic and somatic growth of beluga (Huso huso) in new condition such as inland brackish water

Taking into consideration culture of beluga (Huso huso) in new condition such as inland brackish water, it is very important to study nutrition requirements and effect of different diets on gonadic and somatic growth as well as physiological condition. In this research 74 beluga (4 years old) cultured in brackish water earth ponds in Bafgh fisheries research station, were selected and distributed in 8 circular cement ponds. Feeding was done in 4 formulated diets with fixed protein level and 4 energy levels (400,425,450,475 kcal/100gr). Samples were biopsied in the first and the end of experiment to determine sexuality and stage of maturation. To study gonad tissues, the hematoxylin-eosin method was used. Results indicated that somatic and gonadic growth index was affected by diets. Growth somatic overlapped in both sexes. Sexual maturation stages were not the same in both males and females and transition from stage II in males was more rapid than females. Considering the results in this study, diet treatments influenced on somatic growth in both sexes and gonadic growth in females. It seems to state of somatic and especially gonadic growth in brackish water is suitable. Therefore, inland brackish water environment can be introduced as a suitable environment cultivation of beluga

Investigation of Litopenaeus vannamei culture in brackish waters of Bafgh, Yazd Province

This survey is part of the investigation on feasibility of introduction of Litopenaeus vannamei Boone, 1931 in shrimp culture industry of Iran. The objective was evaluation of the adaptation of the white leg shrimp, L. vannamei to brackish groundwaters of the Bafgh area in Yazd province. Around 120000 shrimp postlarvae (PL7 and 15) were stocked in four 0.15ha earthen ponds (17 and 23 ind/m ^(2)) in July 2005 and the culture period took about four months. Physicochemical and biological factors were studied during the culture. Shrimps were fed with commercial feed of the L. vannamei. Results showed low survival (19.2%) and growth (2-2.5g mean body weight). Based on the assessments, the limnological factors were most unfavorable elements causing the low growth in the shrimp. Concentration of K, Ca, Mg and Na Fe (II and III), different heavy metals, nitrogenous compounds, water hardness and the season and thermal periods are probably the most essential factors affecting production yield of the shrimp because of underground origin of the water. Also, the structure of ponds and drainages, presence of invasive water plants and insects may have affected the survival and growth of the shrimp as well

Production yield of the white-leg shrimp, Litopenaeus vannamei (Boone, 1931) culture in brackish water of Yazd Province

This survey is one of the researches of Investigation on feasibility of introduction of Litopenaeus vannamei in shrimp culture industry of Iran project. The aim of this survey was study about probability of adaptation of the white-leg shrimp, L. vannamei with brackish groundwater for culture at central Iran. 120/000 postlarvae (PL7&15) were stocked in four 0.15ha earthponds (17 & 23 N/m^2), in July 2005. Culture continued for about four months. Physicochemical and biological factors were studied. Shrimps were fed with L. vannamei commercial food. Results showed low survival (19.2%) and growth (2-2.5gr mean body weight while capture). Limnological factors may be the most important agent for unfavorable culture efficiency at based on the results of measurements. Concentration of K^+ (40mg/l), Ca^+2 (370- 472mg/l), Mg^+2 (340-407mg/l), Na^+ (3450mg/l), and their proportions; Fe^+2&+3 (0.18-1.17mg/l), Zn^+2 (0.072mg/l), nitrogenous compounds especially NH_3 (3.22mg/l), water hardness (2350-2870mg/l), different heavy metals; season of stocking and daily thermal periods (2.5-12°C with 8°C mode) are probably the most essential factors effecting production yield of L. vannamei, mainly because of underground origin of the water. Also, the structure of ponds and drainages, presence of invasive water plants and insects may affect survival and growth, as well

An investigation on possibility of nile tilapia (Oreochromis niloticus) feminization under the condition of brackish water in Bafgh

This study was aimed to investigate the effect of different doses of oral diethylstilbestrol (DES) on feminization of Nile tilapia (Oreochromis niloticus) larvae under the condition of brackish water in Bafgh fisheries research center. This Experiment was comprised of two control groups in two replicates and two experimental ones in three replicates. At the beginning of the trial, a number of 2150 larvae were randomly distributed among 10 replicates that were under treatment for 45 days. The diets in two control groups, i.e. non-treated, C1, and ethanol treated feed, C2, and the ones in two experimental groups, i.e. 200 and 400 mg DES/k of feed, E1 and E2, were administrated to 7 day post fertilization (dpf) larvae for a period of 35 days and then until day 45, the larvae were fed with ordinary feed. At the end of the trial, the gender ratio of larvae in different groups was determined by squash test in 50 randomly selected individuals from each replicate. The results showed no significant differences for gender ratios within control groups (respective male to female ratio in C1 and C2 was 47:53 and 57:43). However, the corresponding ratios within experimental ones, fed with 200 and 400 mg DES/k of feed respectively, was significantly different (P<0.05). Noteworthy that the percent of females between two experimental groups (E1 and E2) was not significantly different (70.0 and 64.7 respectively) but it was significantly different with ratios in experimental groups (P<0.05). The total body length and live body weight were determined at the begging and then at day 30 and 45, it was randomly measured in 20 larvae from each replicate. At the beginning of the experiment, the mean body weight and total length of larvae was 0.012 gram and 1.03 centimeter respectively. The respective averages at day 30 and 45 were significantly different among groups (P<0.05). Survival rate was significantly different among groups (P<0.05), being highest in E1 and E2 respectively whereas lowest in control ones (56.51 and 58.84 in C1 and C2 respectively)

An investigation on all male production of nile tilapia (Oreochromis niloticus) under the condition of brackish water in Bafgh

This study was aimed to investigate the effects of different doses of two hormones and an anti-aromatase, i.e. 17a methyl testosterone (MT), methyl di hydrotestosterone (MDHT) or mestanolone and letozole in masculinization of Nile tilapia (Oreochromis niloticus) under the condition of brackish water in Bafgh station situated in Yazd province in center of Iran. Each experiment in this study was consisted of 5 treaments with 3 replicates each. A number of 1725 larvaes was distributed randomly among 15 replicates at the beginning of each experiment. Each experiment lasted 45 days and the larvaes were reared in aerated flow-through pots and fiberglass tanks filled with brackish water. The averages for temperature, salinity, pH and dissolved oxygen of water were 26.9 ê, 8 g/l, 7.6 and 5.78% respectively during this study. In experiment 1, three different doses of 40, 60 and 100 mg MT/k of feed were fed to different groups of 7 day post fertilization (dpf) larvaes for 45 days from the beginning of the experiment. The results showed that the larvaes in 40 mg group were 100 percent masculinized based on squash test performed at the end of the experiment but masculinization rates of those in 60 and 100 mg groups were 99.7 and 96.2 perecent respectively. Based on Dunkan test, total body length and weight averages measured in biometry 3 (at the end of the experiment) were not significantly different among groups but in biometry 2 (30 days after the beginning of experiment), they were significantly lesser only in 40 mg group (P<0.05). There was significant differences in survival rate of different groups of larvaes in this experiment based on chi-square test (χ=31.166, P<0.05) and the values in 40 and 100 mg groups (74.5 and 82.9% respectively) were lesser than those in 60 mg, control 1 and control 2 groups (84.3, 89.0 and 87.0 respectively). In experiment 2, masculinization rates of two different groups of larvaes immersed in 1800 µg MDHT/liter once in 10dpf and twice in 10 and 14dpf were 80.0 and 91.9 percent respectively. There were no significant differences in total body length and weight averages measured in biometry 2 between different groups but significant differences were observed in total body length only in biometry 3 (P<0.05) where the highest values occurred in experiment 1 and control 1 groups and the lowest one in experiment 2. Significant differences observed in survival rate of different groups of larvaes in this experiment based on chi-square test (χ=15.165, P<0.05) and the rates in experiment 1, control 2 and 3 groups (89.9, 86.4 and 89.9% respectively) were higher than those in experiment 2 and control 1 groups (82.0 and 82.3 respectively). In experiment 3, three different doses of anti-aromatse letrozole (200, 300 and 400 mg/k feed) were fed to different groups of 7 day post fertilization (dpf) larvaes for 45 days from the beginning of the experiment. The larvaes in 400 group .were all masculinized whereas the masculinization rates in 200 and 300 mg groups were 99.0 and 99.6% respectively. There were significant differences in total body length and weight averages measured in biometry 2 and 3 among groups in this experiment (P<0.05) where the highest and the lowest values occurred in control 2 and experime2 groups respectively. Based on chi-square, the survival rate of different groups was significantly different (χ=41.119, P<0.05) and the lowest rate occurred in experiment 2 group. No significant differences observed in gender ratios within all control groups in this study based on chi-square test. According to the findings acquired under the condition of brackish water at the present study, it would be potentially recommended to use MT and letrozole for the production of all male populations of Nile tilapia fish in order to provide fish farmers with no harmful environmental impacts on water sources in rivers and seas which occured due to the uncontroled breeding of tilapia. However, more research is needed to draw firm conclusions to use hormones and in especial anti-aromase letrozole because of the shortage of sufficient data in current references

Evaluation of different levels of feeding and their effects on growth and FCR in grower rainbow trout in fiberglass tanks under the condition of brackish water in Bafgh station

The objective of this study was to evaluate 4 levels of feeding defined as 1.ad libitum to satiation, 2.Standard feeding (based on fish size and water temperature), 3.10% less than that of standard feeding and 4.10% more than that of standard feeding on growth, feed conversion rate (FCR) and carcass quality of rainbow trout (Oncorhynchus mykiss) reared in 12 aerated flow-through fiber glass tanks (2500l rearing volume, n=150 fish per tank, body weight average 45 g) comprised of 3 replicates under the condition of brackish water (salinity 8.4 g/l) in Bafgh Fisheries Research Station in center of Iran. The increase in average body weight (BW) and size of fish in different feeding groups was significantly different (P<0.01) during the experiment (101 days) and the highest average BW and size increase occurred in the group fed ad libitum to satiation. On the contrary, FCR (average ±SE: 1.27±0.09) in this group was statistically lower than that of the other groups (P<0.01). The chemical composition of carcass was significantly influenced by the level of feeding (P<0.01) and the percent of moisture, crude protein and ash was the lowest in the group fed ad libitum to satiation while the crude fat percent in this group was the highest of all. According to the results obtained in this study, an ad libitum feeding regime is suggested for rainbow trout production in fish culture systems of central desert regions in Iran under the condition of brackish water. However, further investigations are needed to draw firm conclusions, especially in earth pond cultures with different conditions, enriched in live food

An investigation on feasibility of introduction of tilapia to aquaculture industry of inland brackish waters at desert areas of Iran

Tilapia is the third most cultured fish in the world. Studies about tilapia were started in Iran from November 2008 for the first time. Immature black Nile tilapia, Oreochromis niloticus, and red hybrids were stocked in 6 cylindrical 3m3 fiberglass tanks from September 2009, for breeding. Samples were stocked in 27±0.5ºC water temperature, 11.5±0.5ppt salinity, 2500lux light/day (18h L: 6h D), sex ratio of 1:3 (male: female) at 5/m^3 density. Body weight and total length of spawned females were measured. Eggs were incubated in conical glass jars, after counting. Length of the large diameter and weight of 25 eggs were measured in the laboratory. Absolute and relative fecundity, spawning frequency of both black and red broodstocks, incubation period and hatching percent of the eggs were acquired. Power regression between body weight and total length of spawners, Pearson correlation coefficients of body weight and total length against absolute and relative fecundity, weight of egg clutch, length and weight of egg were obtained. Black and red spawners were compared for fecundity and egg quality, by t-student test (p<0.05). Spawning frequencies and optimum ranges of length, weight and age of spawning in black and red female tilapias were defined