Digital light microscopy to characterize the scales of two goatfishes (Perciformes; Mullidae).

The normal and lateral line scales from above the head and four flank regions were investigated in two goatfishes by using light microscopy to evaluate the microscopic characteristics of scale surface ornamentation from different body parts of these fishes and to add new morphological data for their discrimination. The body scales were removed and digital images captured with a Dino-Lite digital camera connected to a Leica compound microscope. The presence of both transverse and longitudinal radii was a distinctive characteristic for the scales of studied goatfishes. The most distinctive features of the key scales discriminating the two goatfishes were the scale shape, the presence of irregular grooves in scale surface, the presence of transverse radii in the lateral fields, and the availability of lepidont at the anterior field. The lateral line scale ornamentations were almost similar in two species; however, the lateral line canal was branching in Parupeneus heptacanthus. Scale extension index indicated that in both species, the dimension of normal key scales tends to the right, while the dimension of lateral line scales tends to the left. This study accentuated that scales from different body regions may exhibit variation in surface ornamentations, that scale morphology could successfully be used to discriminate the examined goatfishes, and that the use of fish scale microscopy is an easy and relatively rapid method and does not require fish sacrifice. Since fish identification is essential for the conservation and management of species, the use of scale morphology to this purpose appears particularly promising.

Microanalysis of scale morphology in killifish, Aphaniops hormuzensis inhabiting ecologically diverse environments (Cyprinodontiformes; Aphaniidae).

Ecologically, Aphaniops hormuzensis populations occupying diverse environments in southern Iran and showed substantial morphological variation across its range. In this study, three different habitats were chosen and identified as group A (sulfur rich spring), group B (salty River), and group C (urban canal), and scale microstructures and scale shape was inspected among three groups. The SEM imaging indicated that lepidonts were more developed on the scale of larger (group C, SL > 30 mm) than younger fish (group A, SL < 30 mm). We tentatively concluded that lepidonts are formed during scale development so that in the earlier stages of fish development, scales probably do not have lepidont. Also, the size and shape of lepidonts vary between the populations, and their shape and orientation within a given species affected by the fish size rather than the local ecological conditions of habitats. The number of radii was relatively higher in group C (12.58 ± 0.66 in males and 13.00 ± 1.89 in females). Similar to what is mentioned before in the case of lepidont, the inter-population variation in the number of radii seems to be influenced by fish size. Group A (SL < 30 mm) had a relatively large focus diameter (0.14 ± 0.02 in males and 0.36 ± 0.44 in females). It is assumed that the focus size is large at the earlier stage of fish development, but later during the fish growth, and by increasing the scale size, the focus diameter is reduced. In conclusion and agreement with previous studies, scale surface morphology and microstructure could be employed to discriminate certain populations, while scale size and J-indices could not help in distinguishing the populations. It is also proposed that the characteristics of scale morphology in the population-level are influenced by the combination of genetic, and environmental factors, as well as fish development.

Characterization of age-dependent variability in the flank scales of two scorpaeniformes fishes by applying light and scanning electron microscopy imaging.

The morphology of scales from four flank regions in two species of Scorpaeniforme fishes of the family Platycephalidae was studied by applying light and scanning electron microscopy, and the age-dependent variability of scale structures was discussed. The scales of four flank regions from three size classes in both species were ctenoid. The posterior margin of all the ctenoid scales was formed by two rows of cteni, while the three complete rows of cteni were not observed in the examined scales. The cteni of both rows were similar in morphology. Some scale characteristics showed alteration during the fish growth, including the shape of the anterior region of scale in Platycephalus indicus, the presence of lepidonts in Grammoplites suppositus, and the general shape of scale as well as the indices SCL.SCW and JSW.SL in both species. Also, the number of cteni in posterior margin of scales was increased during fish development, while their general morphology did not change significantly. The number of cteni in the scales of small and large fishes in G. suppositus was found to be obviously lower than P. indicus. By considering the function of lepidonts in improving the hydrodynamic efficiency of swimming, it can be assumed that G. suppositus is not probably very active in swimming as P. indicus. As a conclusion, modification in the ornamentations of the posterior region are subject to alteration during the growth of the fish. Besides its developmental changes, some scale characters in the adult forms have taxonomic significance, including the square-shaped scales in P. indicus vs. the oval-shaped scale in G. suppositus; a total of 26-31 radii in the anterior field in P. indicus vs. 11-12 radii in G. suppositus; the presence of many (54-58) cteni in the posterior part in P. indicus vs. a moderate (19-23) cteni in G. suppositus. These characters could be used as additional morphological data to be used for studying systematics and even phylogeny of the flathead fishes.

Histomicroscopy and normal anatomy of the adult killifish Aphanius hormuzensis (Teleostei; Aphaniidae) from the Persian Gulf coastal environment.

The histomicroscopy and normal anatomy of the major body organ systems were investigated in the adult killifish, Aphanius hormuzensis using histological examination, X-ray imaging, double staining, light microscopy and scanning electron microscopy (SEM). Based on the histomicroscopic observations, the kidney, liver and swim bladder in the studied species were comparable to other fish models. The anterior portion of the kidney is bulbous, while the posterior portion is narrow and elongated; the liver has a single lobe and the swim bladder is a single-chambered organ with no connection to the digestive tract (physoclistous). X-ray imaging and double staining examination showed 12 abdominal and 15 caudal vertebrae and a single hypural plate in the caudal skeleton. According to light microscopy, the scales were rounded to pentagonal in shape with three types of radii (primary, secondary and tertiary), and the urohyal bone was elongated. SEM microscopy showed a single row of tricuspid teeth on the upper and lower jaw, respectively, each tooth has two lateral cusps that are shorter than the middle one. The number of teeth was 17-18 in the upper jaw and 19-20 in the lower jaw. The saccular otoliths were rounded-trapezoid in shape with a moderately incised and V-shaped excisura. The members of killifishes are an important group for biologists because of their evolutionary properties, regeneration capacity and usefulness as biological control and also for the ecotoxicological assessment of environmental pollution. The outcomes of this study may provide a useful basis for future research on the genus Aphanius.

Faunal data and envenomation emergency first aid of cone snails (Conus spp.) in Qeshm Island, the Persian Gulf.

OBJECTIVE: To investigate the fauna of a highly venomous marine species group, the cone snails (Family Conidae), in the shores of Qeshm Island, of evaluating the possibility of envenomation in the area and summarize recommendations for emergency first aid. METHODS: Shores surrounding Qeshm Island were surveyed to collect cone snails during cold (February and March) and warm (May and June) seasons of 2017. Collected snails were identified to the species level. Abundance and species richness were estimated in shores of different structures, including muddy and sandy-rocky shores. Also, the most updated medical literature was reviewed to summarize related emergency first aid. RESULTS: Three cone snail species were recorded from southern sandy-rocky shores of the Island, in decreasing order of abundance, included crowned cone (Conus coronatus) (65%), feathered cone (Conus pennaceus) (28%), and frigid cone (Conus frigidus) (7%). Abundance of these species were significantly higher in cold season compared to the warm season (P < 0.05). No cone snails were recorded along the northern muddy shores of the Island. CONCLUSIONS: Envenomation can cause various symptoms ranging from minor local pain to systemic paralysis and death due to respiratory failure. We recommend an awareness programme for the seashore visiting public.

Study the symbiotic crude oil-degrading bacteria in the mussel Mactra stultorum collected from the Persian Gulf.

Symbiotic associations are complex partnerships that can lead to new metabolic capabilities and the establishment of novel organisms. The diversity of these associations is very broad and there are still many mysteries about the origin and the exact relationship between the organisms that are involved in a symbiosis. The aim of the present study is to find symbiotic crude-oil degrading bacteria in the mussels that collected from the Persian Gulf. Fifteen crude-oil degrading bacteria were isolated from Mactra stultorum mussel that collected from oil contaminated area at Persian Gulf. According to high growth rate on crude oil five strains were selected from 15 isolated strains for more study. Determination of the nucleotide sequence of the gene encoding 16S rRNA show that these isolated strains belong to: Alcanivorax dieselolei strain BHA25, Idiomarina baltica strain BHA28, A. dieselolei strain BHA30, Alcanivorax sp. strain BHA32 and Vibrio azureus strain BHA36. Analysis of remaining of crude oil by Gas Chromatography (GC) confirmed that these strains can degrade: 64%, 63%, 71%, 58% and 75% of crude oil respectively.

Sea snakes (Elapidae, Hydrophiinae) in their westernmost extent: an updated and illustrated checklist and key to the species in the Persian Gulf and Gulf of Oman.

The Persian Gulf is known as the westernmost distribution limit for sea snakes, except for Hydrophis platurus (Linnaeus, 1766) that reaches southeastern Africa. Previous identification guides for sea snakes of the Persian Gulf and its adjacent waters in the Gulf of Oman were based on old data and confined mostly to written descriptions. Therefore, a series of field surveys were carried out in 2013 and 2014 through Iranian coastal waters of both gulfs to provide a comprehensive sampling of sea snakes in the area. This paper presents an illustrated and updated checklist and identification tool for sea snakes in the Persian Gulf and Gulf of Oman, which are based on new material and a review of the literature. This checklist includes ten species of marine hydrophiines, of which one, Microcephalophis cantoris (Günther, 1864), is a new record for the area. All specimens examined herein are deposited and available at the Zoological Museum of Shahid Bahonar University of Kerman, Kerman province, Iran.

Enrichment and isolation of crude oil degrading bacteria from some mussels collected from the Persian Gulf.

To date, little is known about existing relationships between mussels and bacteria in hydrocarbon-contaminated marine environments. The aim of this study is to find crude oil degrading bacteria in some mussels at the Persian Gulf. Twenty eight crude oil degrading bacteria were isolated from three mussels species collected from oil contaminated area at Persian Gulf. According to high growth and degradation of crude oil four strains were selected between 28 isolated strains for more study. Determination the nucleotide sequence of the gene encoding for 16S rRNA show that these isolated strains belong to: Shewanella algae isolate BHA1, Micrococcus luteus isolate BHA7, Pseudoalteromonas sp. isolate BHA8 and Shewanella haliotis isolate BHA35. The residual crude oil in culture medium was analysis by Gas Chromatography (GC). The results confirmed that these strains can degrade: 47.24%, 66.08%, 27.13% and 69.17% of crude oil respectively. These strains had high emulsification activity and biosurfactant production. Also, the effects of some factors on crude oil degradation by isolated strains were studied. The results show that the optimum concentration of crude oil was 2.5% and the best degradation take place at 12% of salinity. This research is the first reports on characterization of crude oil degrading bacteria from mussels at Persian Gulf and by using of these bacteria in the field the effect of oil pollution can be reduce on this marine environment.