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The relationships between somatic growth and otolith dimensions, otolith size to estimated age and growth parameters of the tigertooth croaker ( Otolithes ruber) were investigated in 100 specimens (size range: 19.1-52.0 cm, total length) from the Oman Sea area, September 2014. All 100 otoliths were sectioned and determined by age. The oldest specimen was a 4.5-year-old female with a total length of 40.6 cm; the youngest specimen was also a female estimated at 1 year of age with a total length of 19.1 cm. The von Bertalanffy growth equation was estimated as Lt = 54.70 (1 − exp (−0.37 ( t + 0.21))). Concluded was that there is a significant relationship between body size, otolith dimensions and estimated age of Otolithes ruber. [ABSTRACT FROM AUTHOR]

In this study, the reproductive biology of female freshwater crab Sodhiana iranica , oogenesis and ovarian development were described. An H-shaped ovary consisting of a pair of long ovarian sacs connected by a narrow bridge tube was located in the cephalothorax on the dorsal side of the stomach. Females at different stages of ovarian development were anesthetized and their ovaries were removed, photographed, fixed, and processed for histological examination. Based on the light microscopic observations of cells’ sizes, chromatin patterns, and amount of lipid vesicles, the female germ cells could be classified into seven different stages: (1) oogonia (Oog), (2) primary oocytes (pOc), (3) early previtellogenic oocyte (Oc1), (4) late previtellogenic oocyte(Oc2), (5) early vitellogenic oocyte (Oc3), (6) late vitellogenic oocyte (Oc4), and (7) mature oocyte (mOc). Oog are small oval-shaped cells with irregular-shaped nuclei. Oog undergo first meiotic division to become primary oocytes. The primary oocytes are small oval-shaped cells with large nuclei. The secondary oocytes derived from 2nd meiosis and comprise five steps. Four ovarian development stages were found for females based on the number and types of oocytes present in each stage: spent I (Spent), II (Proliferative) and III (Premature) and stage IV (Mature). The ovaries, macroscopically, varied in size and color during each developmental stage and, microscopically, the ovarian stages differed in proportion oogonia, and the secondary oocytes. During ovarian stage I, ovary contains primarily oogonia, primary oocytes and Oc1. In stage II, contains mainly Oc1, Oc2, and Oc3, while in stage III the predominant cells are Oc4. Mature oocytes appear synchronously in stage IV. [ABSTRACT FROM AUTHOR]

Summary This study presents some traits of the Aphanius ginaonis life history in the Geno hot spring and explains the potential risks of its extinction. Sampling was from March 2009 to February 2010. A total of 61 males and 71 females were measured (total length) and weighed, with data on reproductive biometry also taken. Growth parameters were determined in addition to weight-length relationships: W ( t) = 0.012TL3.42, R2 = 0.96 for females and W ( t) = 0.0101TL3.38, R2 = 0.94 for males. A. ginaonis females showed an asymptotic total length (TL∞) of 53.03 mm; the growth coefficient, K (year−1) 0.15, t0 (year) 1.01; and natural mortality coefficient M (year−1) 0.62. In males the value for TL∞ was 48.83 mm; for K (year−1) 0.2, t0 (year) 0.44; and M (year−1) 0.49. The relationship between absolute fecundity and fish size (total length, body weight or age) showed a strong correlation to body weight. The A. ginaonis population is threatened with extinction - and a co-management in cooperation with the local population for strong protection measures is urgently needed. [ABSTRACT FROM AUTHOR]

Length-weight relationships ( LWRs) for four little-known fish species collected in the northern Persian Gulf (south of Iran) are presented, namely, Leiognathus lineolatus, Grammoplites suppositus, Eupleurogrammus muticus and Acanthocepola abbreviate. Thus far, these are the first LWRs for these species in the international scientific literature. [ABSTRACT FROM AUTHOR]

Length–weight relationships, W = aL b, were calculated for three species of mudskippers: Scartelaos tenuis, Periophthalmus waltoni and Boleophthalmus dussumieri from the Iranian coast of the Persian Gulf. Values of b ranged from 2.10 to 2.86 for both sexes at seven sites for the three species. [ABSTRACT FROM AUTHOR]

Despite the increasing interest in mangroves as one of the most carbon-rich ecosystems, arid mangroves are still poorly investigated. We aimed to improve the knowledge of biomass and soil carbon sequestration for an arid mangrove forest located at the Azini creek, Sirik, Hormozgan Province (Iran). We investigated the biomass and organic carbon stored in the above and belowground biomass for three different regions selected based on the composition of the principal species: (1) Avicennia marina, (2) mixed forest of A. marina and Rhizophora mucronata, and (3) R. mucronata. Topsoil organic carbon storage to 30 cm depth was also estimated for each analyzed area. Biomass carbon storage, considering both aboveground (AGB) and belowground biomass (BGB), was significantly different between the cover areas. Overall, the mean forest biomass (MFB) was 283.1 ± 89 Mg C ha -1 with a mean C stored in the biomass of 128.9 ± 59 Mg C ha -1 . Although pure Rhizophora stand showed the lowest value of above and below tree carbon (AGC + BGC); 17.6 ± 1.9 Mg C ha -1 ), soil organic carbon stock in sites under Rhizophora spp. was significantly higher than in the site with pure stand of Avicennia spp. Overall, forest soil stored the highest proportion of Sirik mangrove ecosystem organic carbon (59%), with a mean value of 188.3 ± 27 Mg C ha -1 . These results will contribute to broaden the knowledge and the dataset available, reducing the uncertainties related to estimates and modeling of carbon pools in arid mangrove ecosystem, which also represent an important climatic threshold of mangrove worldwide distribution., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)