بررسی میزان تخم گشایی و ریخت سنجی ناپلیوس های آرتمیا (artemia ranciscana) در آب های نامتعارف منطقه سیستان، جنوب شرقی ایران

در این مطالعه میزان تخم گشایی و ریخت سنجی ناپلیوس های آرتمیا (artemia franciscana) در آب های ژرف منطقه سیستان در شرایط آزمایشگاهی بررسی شد. به این منظور، سیست ها در چهار تیمار (با سه تکرار) شامل 1- آب مقطر + نمک دریا (شاهد؛ شوری ppt 35.37، t1)، 2- پساب آب شیرین کن (شوری ppt 42.88، t2)، 3- آب چاه ژرف (شوری ppt 17.35، t3) و 4- آب چاه کشاورزی (شوری ppt 28.46، t4) کشت شدند. تیمارها در طی دوره آزمایش (24 و 48 ساعت) در شرایط استاندارد شامل دمای 27 درجه سانتی گراد، نور 37 میکرومول بر متر مربع بر ثانیه و 12 ساعت روشنایی/12 ساعت تاریکی نگهداری شدند. نتایج نشان داد که بین تیمارها از نظر میزان تخم گشایی (بین همه تیمارها، (p<0.05 و درازای آرتمیا (بین برخی تیمارها، p<0.05) تفاوت معنی دار وجود داشت. بیشترین میزان تخم گشایی بعد از 48 ساعت برای تیمار 1 (%5.41 ± 71.32) و سپس به ترتیب برای تیمار 3 (%4.28 ± 67.19)، تیمار 4 (%2.33 ± 51.19) و تیمار 2 (%2.78 ± 47.81) ثبت شد. طول آرتمیا در تیمار 3 (0.06 ± 0.64 mm) بیش از تیمارهای 1 (0.62 ± 0.05 mm)، 4 (0.04 ± 0.59 mm) و 2 (0.05 ± 0.56 mm) بود. در بین جمعیت هر یک از تیمارها شکل رایج آرتمیا در تیمارهای 3 و 4 بعد از گذشت 48 ساعت از زمان انکوباسیون instar 2 بود، در حالی که در دو تیمار دیگر instar 1 غالب بود. خصوصیات ریختی آرتمیا بین تمام تیمارها مشابه و طبیعی بود. بر این اساس تخم گشایی و نگهداری لارو a. franciscana تا مدت 48 ساعت پس از انکوباسیون به ویژه در پساب آّب شیرین کن از کارایی خوبی برخوردار بود. داده های ارائه شده در این مطالعه برای اولین بار اطلاعات مفیدی در باره تخم گشایی سیست آرتمیا و نگهداری نوزاد در منابع آب نامتعارف در منطقه سیستان فراهم می کند.

investigating the hatchability and nauplii biometry of artemia franciscana in unconventional waters of sistan region, southeast iran

introduction: nowadays, using unconventional water, especially in arid and semi-arid areas, has increased as a result of global population increase, urbanization and climate change. using these water sources for aquaculture is suggested for optimal utilization and reduction of their adverse effects on the environment. artemia is an aquatic crustacean that is distributed all over the world. it plays an important role in the aquatic food chain due to containing a variety of high nutrients such as proteins, amino acids, fatty acids, vitamins and antioxidants. these organisms are the most common live-food item in the aquaculture industry to feed the larval stages of fish and crustaceans in different parts of the world. artemia can grow in various saltwater environments. the water sources suitable for them do vary considerably in terms of ionic composition, climatic conditions, seasonality, productivity, altitude, and other characteristics. among the species of the genus artemia, a. franciscana is the most important one for aquaculture use, and it has been introduced in salt-waters for integrated artemia–salt production. this species is characterized by the standard features of the short-life cycles: highly adaptable to adverse environmental conditions, easy cultivation and easy availability. the aim of this study was to investigate the feasibility of hatching and growth performances of artemia (a. franciscana) in the unconventional water conditions in sistan region, southeast iran under laboratory conditions.materials and methods: the present study was carried out in the laboratory of reproduction and breeding aquatic animals, hamoun international wetland research institute located in zabol research institute in february 2024. hatching rate, growth performance (comparison of body length and width), abundance of each biological form and health (comparison of morphological characteristics) of a. franciscana under breeding conditions of unconventional waters in sistan region were investigated in this study. for this purpose, artemia cysts were hatched in plastic jars using three replicated treatments, i.e., control (t1; distilled water + sea salt; 35.37 ppt), desalination wastewater (t2; 48.88 ppt), deep aquifer well water (t3; 16.35 ppt), and well water (t4; 28.46 ppt). all treatments were kept under standard conditions including temperature 27 °c, light 37 μmol/m2/s as well as 12 hours light and 12 hours darkness (12l:12d) during the experimental period. after 48 h of incubation, the hatching rate of artemia cysts was analyzed. in order to evaluate growth performance and health status, at least 30 specimens from each treatment were randomly selected and photographed, then body length and width were measured using digimizer software. water quality parameters including temperature, ph, salinity, ammonia, nitrate, nitrite, sulfate, hardness, cl, mg and cu were recorded using standard methods during the experiment. all data obtained in this study were analyzed using one-way anova, followed by tukey's test for any significant differences among the treatments. pearson's correlation coefficient (r) was calculated for the statistical interpretation of the influence of the physicochemical variables on hatching rate and body length.results and discussion: the results showed that hatchability of cysts and body length of artemia were significantly different among treatments (p<0.05). the highest value of 71.32 ± 5.41% was recorded in t1 followed by 67.19 ± 4.28% in t3, 51.19 ± 2.33% in t4 and 47.81 ± 2.78% in t2 on the 48 h after cyst incubation. the length (mm) of artemia was higher (0.64 ± 0.06) in t3 than in t1 (0.62 ± 0.05), t4 (0.59 ± 0.04) and t2 (0.56 ± 0.05). instar 2 was the dominant form in t3 and t4, while instar 2 was the dominant form in the other two treatments. the morphological characteristics of artemia were similar and normal between all treatments.