Ultrastructure of the chorion and the micropyle of an endemic cyprinid fish, Cyprinion tenuiradius Heckel, 1849 (Teleostei: Cyprinidae) from southern Iran (original) (raw)

Ultrastructural features of the egg envelope of silver carp, Hypophthalmichthys molitrix (Osteichthyes, Cyprinidae

Environmental Biology of Fishes, 2005

We investigated the ultrastructure of the egg membrane surface (unfertilized egg) of Hypophthalmichthys molitrix using scanning electron microscopy. The eggs of silver carp like most other teleosts are surrounded by a relatively thick egg membrane, and have a type III micropyle at the animal pole. The micropyle is almost circular in shape and the micropyle canal is located in its center. The micropyle region is not flat. Round or oval accessory pores are also observed in the canal. The surface of zona radiata is wavy and uneven with a uniform distribution of almost round pores with lips. Microvilli like structure are found in the pore opening region.

Observations on reproductive organs and tissues of two freshwater cyprinid fishes

2012

Two freshwater fish models were selected caught in river Tigris passing through Neinava province, to investigate their reproductive systems. A total of 45 of Hemri Barbus luteus and 32 of Ethri, Varicorhinuus trutta were examined during the period between January 2008 and November 2009 to study their female and male reproductive systems, from gross morphological and histological aspects .Females shown to possess a pair of elongated ovaries situated at the ventral side of the swim bladder, connected with it and other viscera by thin mesenteries. It revealed from histological studies that ovaries are coated with tunica albuginea, from which folds are protruded towards the cavity of the ovary known as oogerous lamella .Six main stages were distinguished in oogenesis, these are: 1. oogonia. 2. chromatin-nucleolus. 3. peri- nucleolar stage which is further divided into: pre-perinuclear stage, early peri-nuclear stage, later peri- nuclear stage. 4. Yolk vesicles stage. 5. Yolk granules st...

Scanning electron microscopy of the operculum of Garra lamta (Hamilton) (Cyprinidae�:�Cypriniformes), an Indian hill stream fish

Australian Journal of Zoology, 2010

The surface architecture of the epidermis on the outer surface of the operculum (OE) and the epithelium on the inner surface of the operculum (EISO) of Garra lamta was examined by scanning electron microscopy. The surface appeared smooth on the OE and wavy on the EISO. A wavy epithelium is considered to facilitate an increase in its stretchability, during the expansion of the branchial chamber. The OE and the EISO were covered by a mosaic pavement of epithelial cells with characteristic patterns of microridges and microbridges. Interspersed between the epithelial cells were mucous goblet cell pores, which were not significantly different in number in the OE and the EISO. Nevertheless, their surface area in the EISO was significantly higher than in the OE. This could be an adaptation to secrete higher amounts of mucus on the EISO for keeping the branchial chamber lining clean, avoiding clogging, the increased slipperiness reducing friction from water flow and increased efficiency in ...

Scale structure of a cyprinid fish, Garra Rossica (Nikol'skii, 1900) using scanning electron microscope (SEM)

2012

The normal and lateral line cycloid scales of the native species Garra rossica (Nikol’skii, 1900), one of the most common and poorly known cyprinid fish in south-eastern Iran have been subjected to the scanning electron microscopy technique in order to study their detailed structure. Normal scale below the dorsal fin showed a clearcut demonstration between the anterior and posterior region with the focus lying towards the anterior region that is covered by reticulate or honeycomb form structures with few mucous pores. There is a wedge shaped circuli only in the anterior and lateral fields which are partitioned by deep and narrow grooves called radii and run radially towards the focus. On the dorsal side, the anterior circuli bear numerous pointed lepidonts. In the posterior section, the scale has several rows of pigmented granules (tubercles) with different shapes from round to oval, semi-oval and even oblong structure. The lateral line scale has a canal which characteristically lie...