The HERMIT CRABS fauna of the Gulf of Oman are not well known. Material of the present study was collected from 14 intertidal localities along the Iranian coast of the Gulf of Oman. The eight HERMIT crab species belong to three families Coenobitidae (Coenobita scaevola ), Diogenidae (Diogenesavarus, D. planimanus, D. custos, Clibanarius signatus, C. virescens and C. longitarsus) and Paguridae (Pagurus kulkamil). Amongst HERMIT CRABS of the present study, Diogenes customs and Pagurus kulkamii are new records for the area. Notes on habitat preferences, most common host shells and geographical distributions for all species are provided.

This study was conducted to determine shell selection behavior in five rare HERMIT CRABS in 6 selected stations located in the intertidal zones of Hormuz Island. Seasonal sampling was conducted during the summer 2010 to spring 2011. The samples of HERMIT CRABS from the stations were separately fixed in 70% ethanol and were transported to the laboratory. HERMIT CRABS were identified with valid key identification at the species level. This identification was verified by comparing the samples with the metatypical HERMIT CRABS samples in the Zoological Museum, University of Tehran. Shells occupied by each of the HERMIT CRABS were identified at the species level. Comparing the samples with the metatypical shells samples in the Conchology Museum, Tokyo University of Science, verified the species. According to our results five HERMIT crab species (Diogenes planimanus, D. tirmiziae, Coenobita scaevola, Dardanus tinctor and Clibanarius longitarsus) with low abundance were identified in Hormuz Island. These HERMIT crab species respectively occupied 5, 4, 3, 4, and 2 species of gastropods for protecting their abdominal section. In general, the shell selection behaviors showed that these HERMIT CRABS use the shells of 11 gastropod species and Thais lacera with 19 occurrences (35.8% of all the shells) was the highest frequent occupied shell. Also, the results showed that station 1 (coast of Hormuz Marine Research Center) had the highest abundance of the HERMIT CRABS. 

This study was conducted to survey species diversity, dominance, and richness indices and determines relationship among some sea water and sea bed characteristics with abundance of the HERMIT CRABS in the coastal zones of Hormuz Island. Six stations were selected in intertidal zones during the four seasons (in Summer 2010 to Summer 2011), and sampling was done by hurling random quadrate) 9 quadrates 0.5´0.5 m). Physicochemical factors such as pH, salinity, temperature, dissolved oxygen, slope, and the sediment grain size were measured and the correlation between the measurements and abundance of the HERMIT CRABS was calculated by the Spearman rank correlation )Significance for all tests was set at 0.05). PAST software was utilized for calculating species biodiversity indexes (Simpson dominance index, Shannon-Wiener species diversity index, and Margalef richness index). Results indicated that station 4 (western coast of Hormuz Quay) contained the most amount of the biodiversity indices and station 6 (Red soil mine) contained the lowest amount of the biodiversity indices. According to biodiversity indices, station 6 is a difficult and inappropriate habitat for the HERMIT CRABS. Shannon-Wiener species diversity index and Margalef richness index showed negative correlation by slope (in bed) and Simpson dominance index showed positive correlation by percent of sand in bed.

This study was conducted to identification and abundance of shell occupied by HERMIT CRABS in 8 selected stations located in the intertidal zones of southern Qeshm Island. Sampling was conducted during the Dec.2013. Some of samples of each station were separately fixed in 70% ethanol and were transported to the laboratory. In this study 605 samples of HERMIT CRABS was surveyed. According to our results eight HERMIT crab species (Clibanarius signatus, Clibanarius virescens, Diogenes avarus, Diogenes planimanus, Dardanus tinctor, Areopaguristes perspicax, Pagurus kulkarniii and Coenobita scaevola) were identified in the intertidal zones of southern Qeshm Island. Our results showed these HERMIT CRABS were occupied with 28, 17, 24, 10, 4, 18, 4 and 3 species of gastropods respectively for protecting their abdominal section. In general 50 gastropod shell species occupied by 8 HERMIT CRABS species. Highest shell occupied by Clibanarius signatus with 28 gastropod shell species. Thais lacera with 13.89% occupations of all the shells was the highest frequent occupied shells. Station 5 (Mangrove forest) had the highest abundance of the HERMIT CRABS and shell occupation.

Study of behavior of aquatic animals is a sensitive indicator to toxicant stress and ecologically can using it to measure the effect of pollutants on aquatic organisms. In this study, were investigated orientation behavior of two groups of infected to lead and Healthy (uninfected) HERMIT CRABS toward target was studied upon exposure to background seawater containing chemical cues in concentrations predatory odor (1, 2, 4 g/l/24h) and Food odor (1, 2, 4 g/l/24h). Also, the assumption was that the HERMIT crab Diogenes avarus ability to understand the chemical and based on orienting to the target and contaminant of Lead can affected the orientation behavior of this species. The results showed that uninfected samples 1) in the control treatment exhibited uniform orientation, 2) In the treatment of food odor, orientation significantly increased towered the bait and 3) in the treatment of predator odor, HERMIT CRABS oriented significantly toward the opposite direction of the target side. Also the result indicated that the Lead affected the orientation behavior of HERMIT crab because of, all of the treatments showed uniform orientation. This observation is probably due to the neurotoxins nature of Lead or animal energy reduction due to removal of contaminant from its body. Generally, HERMIT crab has ability of understanding the chemicals and orientation diagnostic power based on visual and chemical information and contaminant of Lead impacted on this its abilities.

The Neotropical HERMIT CRABS’ behaviour is rarely studied, although it is an important toolfor the conservation of these invertebrates. In this context, the present study aimed to describe theHERMIT crab ethogram on its behaviour in the choice and dispute by shells.60 specimens of HERMITCRABS were collected that were occupying mollusc shells Cerithium atratum, in sandstone reefs. Inthe laboratory, 30 HERMIT CRABS were removed from their host shells by heating, the rest remained intheir shells. The specimens were submitted to five experimental tests: (I) behaviour, (II) shell dispute, (III) shell preference, (IV) specimen behaviour with and without shell, and (V) shell contentionbetween individuals with and without shell. The ethogram was built and evaluated by the Ad Libitumtype of observational sampling methods and by the scanning type, for 30 uninterrupted minutes, records every two minutes, in total 15 observations per each observer. There were eight behaviouralacts divided into 4 categories: immobility, interaction between specimen, environment exploration, and shell occupation. The most frequent behaviour was "walking", for both HERMIT CRABS (54.2%) andthose without shell (59.3%), followed by the rest of the individuals with and without shell, 16.9%and 12.4%, respectively. All HERMITs preferred mollusc shell Bulla striata, when offered inconjunction with the shell of Astrea tecta. However, all specimens returned to C. atratum shells whenit was experimentally offered with all shells. Studies with HERMITs have shown that the species haspreferences of gastropods shell C. atratum.

This study was conducted to determine effective factors on shell selection behavior of HERMIT crab Clibanarius signatus in 6 selected stations which were located in the intertidal zones of Hormuz Island. Seasonal sampling was conducted during the summer 2010 to spring 2011. Samples of each station were fixed in 70% ethanol separately and transported to the laboratory. Shells occupied by each of the samples were identified at the species level. 5 biometric factors in HERMIT crab (cephalothorax length, shield length, cheliped length, cheliped height and HERMIT weight) and 5 biometric factors (shell length, shell width, aperture length, aperture width and shell weight) in occupied shells in each of the seasons and the correlation between the measurements was assessed by the Pearsonʼ s test. The HERMIT CRABS shell utilization in the spring, summer, autumn and winter, were respectively 20, 17, 25 and 22 species. The number of occupied shells in different seasons showed that shell selection in this HERMIT crab species is not based on species-specific gastropods. The highest correlation was found between shell width and cephalothorax length in the HERMIT crab. Results showed a significant correlation between all factors measured that confirmed the shell selection behavior in C. signatus is fully optimized and appropriate shells are available (P<0. 01).

Background and Objective: The presence of HERMIT CRABS in aquatic species and coastal bird’ s food chain and their significant role in environmental remediation highlight the importance of studying these species as biological indicators. Hence, this study assessed the concentration of Lead and Cadmium in sediments of and hard tissue of HERMIT CRABS in KISH Island and compared the results against international standards. Methods: To determine the concentration of Lead and Cadmium, 30 sediment samples and 60 CRABS were randomly collected from the south and southeast of KISH Island. By preparation and analysis of specimens, the concentration of heavy metals was determined using atomic absorption spectrophotometer. Findings: The mean concentration of lead and cadmium in the sediments of the south and southeast coasts of Kish Island were 63. 20 and 2. 94 mg/kg, respectively, both of which are higher than the sediment quality standards of Canada and NOAA. The mean concentration of lead and cadmium in the hard tissue of Coenobita scaevola were 20. 92 and 2. 09 mg/kg, respectively, which is much higher than the average obtained in similar studies on Persian Gulf aquatic animals. Discussion and Conclusion: The mean concentration of lead and cadmium in the hard tissue of Coenobita Scaevola is much higher than the similar studies on Persian Gulf aquatics. The interaction of lead and cadmium in disrupting growth physiology has been proven. Cadmium has a negative effect on nutrition, growth, survival, and reproductive activities of Coenobita Scaevola.

Introduction: Marine ecosystems are impacted by a large amount of pollutants from different sources. The Persian Gulf is a semi-enclosed tropical sea with limited water exchange with the Indian Ocean through the Hormuz Strait. In recent decades, the Gulf countries have grown increasingly in terms of industrial and demographic trends, and one of the consequences of this growth has been the significant increase in oil, urban, agricultural and industrial pollution such as heavy metals with both short and long-term impacts. Heavy metals as major contaminants have been drastically increased in marine ecosystems with anthropogenic activity. This causes increasing extinction rate or complete extinction of some sensitive marine organisms, and biochemical and physiological damage to the organisms, subsequently be transferred to human through the food chain. Lead and cadmium are considered as important toxic pollutants for aquatic animals and the adverse effect of them multiply as they move up the food chain. Evaluating the flexibility of the morphological properties of species populations inhabiting areas with different habitat characteristics and pollution levels would enhance our knowledge the effects of environmental changes on species characteristics (Kuliev, 1988). Like other organism, CRABS adopt a species adjustment mechanism to develop similar morphological characteristics under similar environmental conditions. CRABS’ morphological characteristics are highly sensitive to changes in major environmental factors such as habitat type, environmental pollution, water flow, vegetation, competition, predation, and availability of food resources. Morphometric studies generally use traditional or geometric approaches (Eigdari and Nasri, 2012). Traditional morphometries apply multivariate statistical methods to examine morphological variations within or between groups (Webster et al., 2010). Traditional morphometric studies usually use multivariate statistical tools to assess a set of distance measures. HERMIT CRABS (Coenobita scaevola) are more noteworthy in recent years because of the following: they are included in aquatic and shore birds’ food chain, they have an important role in cleaning the environment and also they are one of the most important animal communities in tidal zones. The purpose of this study is to investigating the effects of heavy metal pollutions on the morphological specifications of HERMIT CRABS in two different pollution contexts by using traditional morphological method. Material and Method: In June 2016, sixty HERMIT CRABS were collected from two different stations in south and southeast of Kish Island (30 sample from each station) and then transferred to the lab. At first, the morphological variables of each sample have been measured by the traditional morphological techniques. Morphological variables Total Length TL Abdomen Length AbL Hard Length HL Carapace Length CL Anterior Shield Length ASL Eyestalk Length El Antennal Length AL 1st Walking Leg Length 1WLL 2st Walking Leg Length 2WLL Cheliped Length CHL Carapace Width CW Eyestalk Width EW Cheliped Propodus Width CPW Total Width TW Sex Sex Table 1: Morphological Variables. c b a Figure 1. (a) Eyestalk Length (b) Carapace Length (C) Total Length Due to the fact that in crustaceans, heavy metals accumulate more in hard tissues, the hard tissue was removed by cutter from the soft tissue. Then, after extraction wet digestion technique according to AOAC, 1980, lead and cadmium concentration were measured by atomic absorption spectrometry. The recovery rates ranged from 96% to 101% for both investigated elements. Finally, in order to compare the lead and cadmium concentrations at each station with global standards, data normality and comparison of lead and cadmium concentrations between two stations, SPSS Software and for the Principle Component Analysis (PCA), the CANOCO software were used. Results and Discussion: According to the results, the mean lead concentration in hard tissue in the southeast station is 2. 38 ppm and in the south station is 22. 49 ppm. As a result, the lead concentration in both stations is more than the world health organization(WHO) standard and in the south station the lead concentration is significantly more than the southeast station. The mean of cadmium concentration in the south station is 2. 38 ppm and it is more than the southeast station which is 1. 8 ppm and in both cases it is more than WHO standard (0. 2 ppm). On the other hand, despite the higher mean concentration of cadmium in the south station, but based on Mann Whitney U test, this difference, is not significant. In the southeast station the carapace length, the eyes stem length, the antenna length, the upper moving legs and the total weight variables are significantly more than the south station. According to the fact that the length of the moving legs in HERMIT CRABS is very important for escaping from the enemies, finding the perfect pair, finding an appropriate oyster and finding food, the effects of lead concentration on this parameter can decrease the survival rate and making intercross, movement and nutrition disorders in these species in south station. On the other hand, results show that the south station samples have less flexibility and we predict less abundance for them in the future. Also, according to the PCA results and with regard to the focus of 57% of the important and effective components correlation in first axis, we can link the average low of the morphological variables of the samples in south station is due to high lead and cadmium concentration in hard tissue in this station. Total Length(TL), Hard Length(HL), Abdomen Length(AL), the Anterior Shield Length(ASL) and the 1st and 2st Walking Leg Length (1, 2 WLL), there is a positive correlation with the cadmium concentration in the hard tissue of the HERMIT crab. Cadmium has a direct impact on the 1st and 2st walking leg in HERMIT CRABS and HERMIT do activities such as finding food, pairs and oysters (to protect the abdomen) and escape from the enemies with walking leg. So the cadmium has a negative effect on nutrition, growth, survival and reproductive activity. Thus, due to the presence of HERMIT crab in the aquatic and shorebirds' food chain as well as its significant role in environmental purification (Seiffabadi et al., 2014), it is also possible to use it as a bio indicator of contaminated water. Also habitats and populations monitoring of this species are proposed on the southern coasts of Iran.