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International Journal of Aquatic Biology - Volume:5 Issue: 3, Jun 2017

International Journal of Aquatic Biology
Volume:5 Issue: 3, Jun 2017

  • تاریخ انتشار: 1396/04/05
  • تعداد عناوین: 6
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  • Brian W. Coad Pages 182-192
    The systematics, morphology, distribution, biology, economic importance and conservation of the herrings (kilkas and shads) of Iran are described, the species are illustrated, and a bibliography on these fishes in Iran is provided. There are 9 native species in the genera Clupeonella, Alosa and Tenualosa in the Caspian Sea and rivers of southern Iran.
    Keywords: Morphology, Biology, Alosa, Clupeonella, Tenualosa, Kilka, Shad
  • Shadi Aminaghaie, Hamid Reza Esmaeili Pages 193-200
    This study presents the first details on morphological and histological characteristics of gonads and gonadal development stages of an endemic tooth-carp, Aphanius sophiae (Heckel, 1847) from a spring-stream system (south of Iran). The sampling was done from March 2012 to March 2013 using dip net, and a total of 226 individuals were collected. The gonads of specimens were removed, and then fixed in 10% formalin solution after checking their morphology and measuring their weights, lengths and widths. Based on the size, shape and weight of the gonads, degree of occupation of the body cavity, presence or absence of ripe oocytes or milt, diameter of the oocytes in the ovary, and histological observations, five stages of sexual maturation in females and males were determined by macroscopic and microscopic criteria. The results of the gonadal stages indicated that A. sophiae spawns at the beginning of spring.
    Keywords: Reproduction, Gonad histology, Sexual maturation, Gonado-somatic index
  • Soheil Eagderi, Hadi Poorbagher, Fatemeh Moshayedi, Seyed Vali Hosseini Pages 201-207
    Morphological development and allometric growth patterns of reared Persian sturgeon, Acipenser persicus, were studied from hatching to 50 days post-hatching (dph). The larvae were sampled, their left sides photographed and seven morphometric characters, including total length, head length, tail length, trunk length, snout length, caudal peduncle and predorsal length were measured. Allometric growth patterns were calculated as a power function of total length and described using the growth coefficient to find important steps in early life history. The total length of the newly hatched larvae and fry were 10.59±0.8 and 38.8±2.9 mm at 1 and 50 dph, respectively. Morphogenesis and differentiation were the highest rates during the first 11 days of early development, i.e. endogenous feeding period. There were higher growth rate of head, snout and tail regions compared with those of other organs from the hatch up to yolk sac absorption, followed by positive or almost isometric patterns, after the begin of exogenous feeding, showing priority to enhance the feeding and swimming capabilities. This study confirmed that most of morphological changes of this species are occurred from hatching until the onset of exogenous feeding i.e. during the lecithotrophic phase.
    Keywords: Ontogeny, Morphogenesis, Morphometrics, Caspian Sea
  • Javd Sadeghinezhad, Hooman Rahmati-Holasoo, Ali Reza Mirzaei, Hosseinali Ebrahimzadeh Mousavi, Narges Zadsar Pages 208-217
    The present study describes the histological and mucin histochemical properties of the alimentary canal (AC) of the pangas catfish, Pangasius pangasius. The results revealed that the mucosa of the oesophagus was lined by a stratified epithelium containing chloride cells and taste buds which suggested mechanic, gustatory and physiologic roles of the oesophagus in this species. The stomach mucosa was lined by a simple columnar epithelium. The lamina propria-submucosa in cardiac and fundic stomach contained gastric glands. The pyloric stomach had the thickest muscularis layer among all the parts of the AC. The villi showed the maximum height and width in the middle intestine. The tunica muscularis and serosa showed the thinnest thickness among all parts of AC. The mucin histochemistry showed that the goblet cells of oesophagus and intestine contained both neutral and acidic with carboxylated and sulfated mucins and there was not acidic mucins in epithelial cells of the stomach.
    Keywords: Pangas catfish, Oesophagus, Stomach, Intestine, Morphology
  • Jandyr A. Rodrigues-Filho, Renato M. Honji, Paulo H. Mello, Maria I. Borella, Alexandre W.S. Hilsdorf, Renata G. Moreira Pages 218-227
    Pseudotocinclus tietensis is endemic to the Upper Tietê River basin and classified as vulnerable. The reproductive biology of this species is still unknown, therefore, we investigated its reproductive strategy and gonad development during its annual reproductive cycle. The fish were collected throughout one year, and histology of the gonads, fecundity and oocyte diameter was conducted. Three phases of gonad maturation were found in males and females (immature, developing, and spawning capable), and the development stages of the gametes were identified within each stage. In the testes, four stages of gamete development were distinguished: spermatogonia, spermatocytes, spermatids and spermatozoa. During spermiation, the spermatozoa were released into the tubular lumen and then continued through the efferent ducts. In the ovaries, five stages of gamete development were identified: chromatin nuclear, perinucleolar, yolk vesicle formation, vitellogenic and ripe. The minimum diameter of ovulating oocytes was 297 µm, and the absolute fecundity was 64 to 306 oocytes. Males with spermatozoa in the lobular lumen and females with vitellogenic and ripe oocytes were found throughout the year. Pseudotocinclus tietensis has asynchronous ovarian development and gametes with fertilization capacity can be eliminated throughout the annual cycle.
    Keywords: Reproductive cycle, Gonads, Pseudotocinclus tietensis, Fecundity, Cascudo
  • James Last Keyombe, Yasindi W. Andrew, Oyugi O. Dalmas Pages 228-235
    The study compared and assessed the diet and condition factors of two fish species, Oreochromis leucostictus and Cyprinus carpio, in Lake Naivasha. Fish samples were collected monthly using gill nets (35-70 mm mesh size) from July to December 2013. Stomach contents of all the specimens were analysed using the point method. Results indicated that detritus was the most abundant food item in the diet of both O. leucostictus and C. carpio accounting for 50% and 63%, respectively, while benthic macroinvertebrates contributed the least with each fish having 2%. Rooting and digging behaviour of the carp probably led to both C. carpio and O. leucostictus ingesting the suspended detritus as their main source of food with C. carpio outcompeting O. leucostictus due to its prolific nature and better adaptability to benthic conditions. Fulton’s condition factor of all the fish samples had values of >1. A comparison of the two fish species showed C. carpio had a condition factor of 1.51 while O. leucostictus had 1.32. The higher condition factor of C. carpio in Lake Naivasha is an indication that the fish have better tissue energy reserves, greater reproductive potential and higher survival rates compared to O. leucostictus with a lower condition factor.
    Keywords: Feeding, Detritus, Algae, Zooplankton, Phytoplankton, Plant materials