An overview of the rotifers of the family Notommatidae (Rotifera: Monogononta: Ploima) from Iran

The diversity and distribution of the rotifers family Notommatidae was studied in the northwest, the south and the southwest of Iran. In total, 29 species were identified, of which, 25 are new records for the country. New records include the following species: Cephalodella forficata, C. cf. mus, C. vittata, C. ventripes, C. lepida, C. inquilina, C. gibboides, C. tincaformis, C. obvia, C. sterea, C. physalis, C. gracilis, Eosphora najas, E. Ehrenberg, E. therina, E. anthadis, Eothina elongate, Monommata actices, Notommata pygma, N. glyphura, N. diasema, N.brachyota, Resticula nyssa, R. melandocusa and Pleurotrocha atlantica. Spatial and temporal patterns of the species diversity were evaluated. Descriptions are provided for all the identified species in detail. Biogeography and environmental conditions favorable for identified species were referred. A great richness of rotifers in aquatic environments is generally found in regions where vegetation predominates, either in aquatic or in the ecotone zone between aquatic and terrestrial environments

Comparing sex hormones levels in Acipenser persicus at the onset of autumnal migration

Levels of two main steroid hormones in gonads, 17-B Stradiol (E2) and testosterone (T) were compared in males and females of Persian sturgeon at the start of autumnal migration to spawning rivers. Hormone levels were also studied for likely relationship with different stages of sexual maturity. The results showed that levels of T and E2 in females at the stage four of sexual maturity is significantly higher than the individuals with immature gonads (ovary in stages 2 and 3). We measured 11.81±2.86Omg/ml and 7±1.15mg/ml of T and E2 in mature females compared to 0.2±0.09mg/ml and 0.736±0.161mg/ml of T and E2 in immature females. Levels of the two hormones in males at different stages of sexual maturity showed that only testosterone was significantly different in mature and immature sturgeons (0.50±0.144 mg/ml and al 4.3 I 25±3.121mg/ml in mature and immature males, respectively) (P=0.04). In males and females with higher sexual maturity, differences between the two hormones were significant (T and E2 levels in females and males were 11.81±2.860mg/ml, 7±1.15mg/ml and 0.50±0.144mg/ml, 0.7023±0/212ng/ml, respectively). However, in immature fish of both sexes, only males showed significantly higher T levels (14.312513.121mg/ml in comparison with 0.2±0.09mg/ml). Disregarding the sexual maturity stages, we found significantly different levels of E2 in both sexes (4.779±1.827mg/ml in females and 0.709±0.121mg/ml in males) (P=0.00). Statistical analyses indicated no correlation between fish age and levels of steroid hormones of the fish (at 90% confidence level)

Caspian whitefish, Rutilus frisii kutum Kamensky, 1901 a potential aquaculture candidate: study on the cumulative effects of salinity and temperature on culture performance

In this study, growth and survival of the Caspian whitefish, Rutilus frisii kutum, (mean weight 0.59±0.06g) have been estimated at different rearing salinities (0, 5 and 10‰) and temperatures (24 and 28˚C). Maximum fish weight gain (493.65±14.07%) and specific growth rate (SGR) (2.74±0.15%), and minimum feed conversion ratio (FCR) (1.66±0.06) were obtained at salinity of 5‰ and temperature of 24˚C. There were significant differences in fish weight and length gain between the two rearing temperatures at salinity of 10‰ and between salinities of 0 and 5‰ at 24˚C (p<0.05). However, salinity and temperature did not significantly affect fish survival. Factorial analysis of variance showed significant cumulative effects of salinity and temperature on fish weight and length gain, final weight and SGR (p<0.05). This study confirmed that optimization of salinity and temperature is crucial in rearing a new fish species. Caspian whitefish fingerlings can be grown well at 5‰ and 24˚C; although, it is recommended that the effects of a broader range of environmental variables as well as feed items must also be examined

An overview of the rotifers of the family Notommatidae (Rotifera: Monogononta: Ploima) from Iran

The diversity and distribution of the rotifers family Notommatidae was studied in the northwest, the south and the southwest of Iran. In total, 29 species were identified, of which, 25 are new records for the country. New records include the following species: Cephalodella forficata, C. cf. mus, C. vittata, C. ventripes, C. lepida, C. inquilina, C. gibboides, C. tincaformis , C. obvia, C. sterea, C. physalis, C. gracilis, Eosphora najas, E. Ehrenberg, E. therina, E. anthadis, Eothina elongate, Monommata actices, Notommata pygma, N. glyphura, N. diasema, N. brachyota, Resticula nyssa, R. melandocusa and Pleurotrocha atlantica. Spatial and temporal patterns of the species diversity were evaluated. Descriptions are provided for all the identified species in detail. Biogeography and environmental conditions favorable for identified species were referred. A great richness of rotifers in aquatic environments is generally found in regions where vegetation predominates, either in aquatic or in the ecotone zone between aquatic and terrestrial environments

Fifteen species in one: deciphering the Brachionus plicatilis species complex (Rotifera, Monogononta) through DNA taxonomy

Understanding patterns and processes in biological diversity is a critical task given current and rapid environmental change. Such knowledge is even more essential when the taxa under consideration are important ecological and evolutionary models. One of these cases is the monogonont rotifer cryptic species complex Brachionus plicatilis, which is by far the most extensively studied group of rotifers, is widely used in aquaculture, and is known to host a large amount of unresolved diversity. Here we collate a dataset of previously available and newly generated sequences of COI and ITS1 for 1273 isolates of the B. plicatilis complex and apply three approaches in DNA taxonomy (i.e. ABGD, PTP, and GMYC) to identify and provide support for the existence of 15 species within the complex. We used these results to explore phylogenetic signal in morphometric and ecological traits, and to understand correlation among the traits using phylogenetic comparative models. Our results support niche conservatism for some traits (e.g. body length) and phylogenetic plasticity for others (e.g. genome size)

Molecular detection of the infection with Fasciola hepatica in field-collected snails of Galba truncatula and Lymnaea stagnalis from West Azarbaijan, Iran

The liver fluke, Fasciola hepatica, is considered as the most common cause of fasciolosis in both domestic livestock and human. This study was carried out to detect the prevalence of the larval stages of F. hepatica in the snails Galba truncatula and Lymnaea stagnalis in West Azarbaijan, Iran. Snail collection was performed through searching 28 freshwater habitats from May to December 2010. Following the identification of the two snail species, polymerase chain reaction (PCR) was utilized to amplify the 28SrRNA gene of F. hepatica in the snails’ tissues. The amplified DNA fragment was subjected to restriction fragment length polymorphism (RFLP) analysis. According to the RFLP patterns, 16.6% of the examined G. truncatula and 1.1% of L. stagnalis were infected by F. hepatica. While there was not detected infection with larval stages of F. gigantica in any examined snails. The RFLP analysis of 28SrRNA gene was proven to be a useful tool for detection of the infection and its transmission by the intermediate hosts, and can help with the establishment of suitable control programs against fasciolosis in livestock and human in any region of interest