Pectoral girdle bones in eurypterygian fishes

Bones of the pectoral girdle skeleton in representatives of 48 genera in 41 families of eurypterygian fishes were studied. The structure and position of the pectoral girdle is relatively stable in eurypterygians. It consists of the extrascapula, posttemporal, supracleithrum, cleithrum, postcleithrum, scapula, coracoid, actinosts, and fin rays. An ectocoracoid is present in some Gasterosteiformes. Most eurypterygians have a posttemporal with distinct dorsal and ventromedial processes. The dorsal process ligamentously articulates with the epioccipital and the ventromedial process with the intercalary when present, and when absent, with the posteroventral margins of the pterotic and exoccipital. In most taxa, the supracleithrum bears a sensory canal and articulates with the posttemporal anteriorly and with the cleithrum posteriorly. The cleithrum is Y-shaped consisting of the anterodorsal, posterodorsal, and ventral rami. Dorsal and ventral postcleithra are present in some Eurypterygii. The scapula articulates with the cleithrum and bears a foramen which is complete or open anteriorly and bordered by the cleithral ventral ramus. Most taxa have four autogenous actinosts that increase in size gradually from the first to the fourth, but in some, the first actinost is fused. The dorsalmost ray is rudimentary in some taxa

Reproduction of an isolated Iranian cichlid, Iranocichla hormuzensis

The reproductive biology of the Iranian cichlid, Iranocichla hormuzensis Coad, 1988, was investigated for 13 consecutive months in lower Mehran River, from August 2008 through August 2009. Four hundred and eighty six individuals (252 males and 234 females) were captured using a seine net (5 mm mesh size). The observed sex ratio was 1M: 0.93F (χ², df = 1, P = 0.414). Mean ± SD of total length (TL) values in males and females were 70.34 ± 8.16 and 62.08 ± 6.51 mm, respectively. The frequency of 56-65 mm size class was higher in females and the 66-75 mm size class in males. A gonadosomatic index (GSI) analyses of females indicated that the reproductive period was during February-June, with a peak in March. Fecundity was best correlated with total body mass (M) (linear regression, r2 = 0.62) condition factor (linear regression, r2 = 0.62) and total length (TL) (linear regression, r2 = 0.56).The absolute fecundity ranged between 48-167 eggs with a Mean ± SD of 107 ± 35.2. Egg diameters ranged from 0.58 to 2.93 mm

UGROŽENE VRSTE RIBA U SVIJETU: Aphanius farsicus Teimori, Esmaeili i Reichenbacher, 2011 (Cyprinodontidae)

Tooth-carp Aphanius farsicus Teimori, Esmaeili and Reichenbacher, 2011 (Cyprinodontidae), or Farsi endemic tooth-carp, was once common in the Maharloo Lake Basin (Fars), but is disappearing now from its native region. This fish has not been listed in IUCN Red Data Book even though it should be due to criteria such as restricted distribution, destruction of spawning grounds and environmental pollution and drought. This vulnerable species has considerable ecological importance, but there are little data on its biology. The limited available data on its systematics, distribution, ecology, reproduction and threats are summarized and discussed.Vrsta šaranozupke Aphanius farsicus Teimori (Esmaeili i Reichenbacher, 2011) iz porodice Cyprinodontidae ili endemična farska vrsta nekoć je bila česta u slivu jezera Maharloo, a danas nestaje iz autohtonog staništa. Ova vrsta šaranozupke još se ne nalazi na popisu IUCN-ove Crvene knjige ugroženih vrsta, iako zadovoljava sve kriterije za svrstavanje na spomenuti popis – ograničena joj je distribucija, mrijestilišna područja se razaraju, zagađuje se okoliš i javlja se suša. Ova osjetljiva vrsta ima veliku ekološku važnost, ali postoji malo podataka o njezinoj biologiji. U ovom članku iznose se i analiziraju ograničeni dostupni podaci o njezinoj sistematici, distribuciji, ekologiji, reprodukciji i prijetnjama koje joj ugrožavaju stanište

A study on genetic differentiation in two species of Iranian bleaks, Alburnus mossulensis and Alburnus caeruleus (Teleostei, Cyprinidae) using simple sequence repeats

The genetic structure of the genus Alburnus is not well known and the phylogenetic relationships among its species are uncertain. In the present study, simple sequence repeats (SSRs or microsatellites) were used to evaluate genetic diversity and genetic differentiation between Alburnus mossulensis Heckel, 1843 from Kashgan River in Lorestan province and A. caeruleus Heckel, 1843 from Gamasiab River in Kermanshah province. Thirty specimens from each species were collected and their genomic DNA was extracted. Polymerase chain reaction was performed using four pairs of SSR markers, including CypG24, BL1-2b, BL1-98 and Rser10, from which a total of 480 bands were amplified. The average observed and expected heterozygosities for both species were similar. In both species, except for Rser10 locus, all loci deviated from the Hardy-Weinberg equilibrium (P <0.05). Average genetic distance and Fst values between the two species were 0.361 and 0.04, respectively. Analysis of molecular variance (AMOVA) revealed more interspecific (94%) than intraspecific (4%) genetic variation. Although four sets of SSR markers developed for other cyprinids showed high level of polymorphisms in the Iranian bleaks, they showed low genetic differentiation between them. Study on the possibility of genetic differentiation of the examined species by more microsatellite loci or other molecular markers such as amplified fragment length polymorphisms (AFLP) are recommended

UGROŽENE VRSTE RIBA U SVIJETU: Aphanius farsicus Teimori, Esmaeili i Reichenbacher, 2011 (Cyprinodontidae)

Tooth-carp Aphanius farsicus Teimori, Esmaeili and Reichenbacher, 2011 (Cyprinodontidae), or Farsi endemic tooth-carp, was once common in the Maharloo Lake Basin (Fars), but is disappearing now from its native region. This fish has not been listed in IUCN Red Data Book even though it should be due to criteria such as restricted distribution, destruction of spawning grounds and environmental pollution and drought. This vulnerable species has considerable ecological importance, but there are little data on its biology. The limited available data on its systematics, distribution, ecology, reproduction and threats are summarized and discussed.Vrsta šaranozupke Aphanius farsicus Teimori (Esmaeili i Reichenbacher, 2011) iz porodice Cyprinodontidae ili endemična farska vrsta nekoć je bila česta u slivu jezera Maharloo, a danas nestaje iz autohtonog staništa. Ova vrsta šaranozupke još se ne nalazi na popisu IUCN-ove Crvene knjige ugroženih vrsta, iako zadovoljava sve kriterije za svrstavanje na spomenuti popis – ograničena joj je distribucija, mrijestilišna područja se razaraju, zagađuje se okoliš i javlja se suša. Ova osjetljiva vrsta ima veliku ekološku važnost, ali postoji malo podataka o njezinoj biologiji. U ovom članku iznose se i analiziraju ograničeni dostupni podaci o njezinoj sistematici, distribuciji, ekologiji, reprodukciji i prijetnjama koje joj ugrožavaju stanište

Age and growth of Alburnus mossulensis (Cyprinidae) in Bibi-Sayyedan River of Isfahan Province

Population structure and growth of Mossul bleak, Alburnus mossulensis, a native species of cyprinids in Bibi-Sayyedan River of Semirom, Isfahan, were investigated by monthly sampling during December 2010 to December 2011. For this purpose, 543 specimens (353 females, 159 males and 31 immature) were caught using seine net (5 mm mesh size) and a cast net. Age groups of males and females were 0+ to 5+. The most frequent age group was 2+ in both sexes. The sex ratio was 1M:2.2F (p0.05). The largest female was 16.80 cm in total length and 49.12 g in weight, while the largest male was 14.10 cm in total length and 28.19 g in body weight. The length-weight relationship was calculated as W = 0.0169L^3.0355 (r^2=0.95) for males, W=0.0061L^3.1751 (r^2=0.98) for females and W=0.0066L^3.139 (r^2=0.99) for all fish (males, females and immature). Regression coefficient (b) based on Pauly test, was significantly different from 3 in females, but not in males (p<0.05), indicating an isometric growth pattern in males and a positive allometric growth pattern in females and all fish

Length-weight and length-length relationships for six fish species from Zohreh River, Iran

The present study reports Length-weight and length-length parameters for six fish species belonging to four families from the Zohreh River. The weight-length relationships were estimated using the equation W= ð›¼Lb. The values of the slope parameter (b) varied between 2.72 and 3.72, with a mean±SD of 3.015±0.18. The values b parameter in the length-weight relationship equations were calculated as 2.72 for Arabibarbus grypus (Heckel, 1843), 2.96 for Capoeta trutta (Heckel, 1843), 2.72 for Garra rufa (Heckel, 1843), 3.25 for Aphanius dispar (Rí¼ppell, 1829), 2.91 for Sillago sihama (Forsskí¥l, 1775) and 3.15 for Glyptothorax silviae Coad, 1981. This study presents the first reference on LWR and LLR for these species in Zohreh River

Age and growth of the Mesopotamian barb, Capoeta damascina, in central Iran

Age and growth of Mesopotamian barb, Capoeta damascina, were studied in the Zayandehrud River, in central Iran, from March 2007 to April 2008. Among the 689 specimens studied, age groups in males ranged from 1+ to 9+ and that in females ranged from 1+ to 10+. The sex ratio (1 M: 1.6 F) was not significantly different from 1:1 ratio. Maximum fork length and weight was 39 cm and 1.115 g for males and 54.2 cm and 2.340 g for females. In all age classes, females were larger than males. The most frequent age groups were 3+ in males and 4+ in females. The highest value for condition factor was observed in June. The growth of C. damascina was described by von Bertalanffy growth curve as k=0.01, L_∞=56.2 cm, t_0=-0.63 for males and k = 0.05, L_∞=117.1 cm and t_0= -0.43 years for females. The length-weigh relationship was described as W=0.0169L^2.95 (r^2 =0.98) for males and as W=0.0155L2.99 (r^2 =0.99) for females, indicating an isometric growth pattern in both sexes. Growth performance index φ` was estimated as 5.73 for males and 6.53 for females, indicating a faster growth rate in females

The effect of different diets on production and population specific growth rate of the freshwater Cladoceran Ceriodaphnia quadrangula (Muller, 1785)

In this study, effects of five different diets including green algae, Scenedesmus quadricauda, mixture of S. quadricauda and baker's yeast, cattle manure, poultry manure, mixture manure (cattle + poultry, 1:1 ratio in weight) were examined on density, specific growth rate and doubling time of freshwater Cladoceran, Ceriodaphnia quadrangula population, at two high and low levels of food density with three replications. The results showed that the maximum population density (184 individuals/50ml), maximum specific growth rate (SGR) (0.18/day) and minimum doubling time (Dt) (3.85 days) were obtained when C. quadrangula fed with S. quadricauda at high density (50×104 cell/ml). In addition, the minimum population density (7.3 ind/50 ml), minimum SGR (0.019 /day), and maximum Dt (36.2 days) resulted from C. quadrangula fed on cattle manure at low diet density (5mg). In this research, maximum (800±34.6µm) (Mean ±SE) and minimum (521±31.6µm) body length of C. quadrangula measured when fed with cattle manure at low diet density and S. quadricauda at high diet density, respectively. In conclusion, the results of current study illustrated that S. quadricauda as diet gave better performance for rearing of C. quadrangula compared to other diet treatments

Karyological analysis of Cyprinion macrostomum Heckel, 1843, from Godarkhosh River, Ilam Province, Iran

In this study, for the first time in Iran, the karyotype of bigmouth Lotak, Cyprinion macrostomum Heckel, 1843, was investigated through examining metaphase chromosomes of seven fish with mean weight 30±5g caught by electrofishing from Godarkhosh River in Ilam Province. To stimulate cell divisions, fish were injected intraperitoneally two times by phytohemagglutinin (PHA). The cell divisions were arrested in metaphase stage by intraperitoneal injection of colchicine. Well-separated cells were obtained from kidney and gill filament and chromosome spreads were prepared and stained with giemsa. Karyotype was obtained as 2n=50. The karyotype consisted of 5 metacentric, 12 submetacentric and 8 telocentric chromosome pairs. Centromeric index, arm ratio and Fundamental Number (FN) were determined as 0-50, 1-∞, and 84, respectively