Abstract
Some growth parameters and feeding aspects of the Lizardfish, Saurida tumbil, in Iranian coastal waters of the Persian Gulf (Bushehr Province), were studied by regular monthly collections during February 2006- February 2007. Among a total of 691 specimens, 538 were females, 114 males and 39 immature. ...
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Some growth parameters and feeding aspects of the Lizardfish, Saurida tumbil, in Iranian coastal waters of the Persian Gulf (Bushehr Province), were studied by regular monthly collections during February 2006- February 2007. Among a total of 691 specimens, 538 were females, 114 males and 39 immature. The total length for females ranged from 26.1 to 58 (38.9±6.7) and for males from 25.5 to 53.5 (34.20±6.7) cm. The total weight of females ranged from 136-1550 (486.7±281.9) and for males from 116 to 1125 (332±225) g. The length-weight relationship for all fish was W= 0.0064L3.042 suggesting an isometric growth for all the fish sample. Condition factor ranged from 0.43 to 0.94 in different months. The relative length of the gut (RLG) was 0.44 on average, suggesting a carnivorous feeding habit of this fish. The maximum and the minimum gasterosomatic index (GI) (gut weight/total weight) occurred in November and in June, respectively. Amongst the 691 studied fish, 187 fish had empty, 297 semifull and 207 full stomachs. On the basis of stomachs contents, Clupeidae, Trichiuridae, Synodonthidae, Carangidae and shrimp were the most important food items, respectively. Based on the results of this study, it could be concluded that the lizard fish is a voracious piscivore species with a positive allometric growth pattern in juveniles and an isometric growth pattern in adults.
Mohammad Hossein Khanjani; Omidvar Farhadian; Yazdan Keivany; Eisa Ebrahimi
Volume 12, Issue 1 , April 2013, , Pages 67-76
Abstract
The most important factors controlling cladocerans production, growth, and morphometric characters are temperature, food quantity and quality and photoperiod. Effects of temperature and photoperiod on production, and morphometric characters of cladoceran, Ceriodaphnia quadrangular, were examined by culturing ...
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The most important factors controlling cladocerans production, growth, and morphometric characters are temperature, food quantity and quality and photoperiod. Effects of temperature and photoperiod on production, and morphometric characters of cladoceran, Ceriodaphnia quadrangular, were examined by culturing on green algae Scenedesmus quadricauda in 250 ml conical flasks (150 ml water). Treatments used for temperature (˚C)and photoperiod (light hours:dark hours) were 20,25,30 (˚C) and 12:12,24:0 and 0:24, respectively. The maximum population density (5.51 ind./ml) obtained at 24:0 and 30 (˚C), while maximum body length (731 µm) and maximum body width (491 µm) obtained at 0:24 and 20 (˚C). Correspondingly, the maximum adult (61 %), maximum neonate (39 %) and young (9 %) in population under culture conditions of 0:24, 12:12,24:0 (L: D) and 20 (˚C) obtained, respectively. Overall, this research showed that growth and reproduction of Ceriodaphniaquadrangula gave better performance at 25 (˚C)and 24:0, light: dark photoperiod.