*3.3.3 Effect of aerial temperature on the total assemblage of gastropods*

Gastropods are adapted to various environmental factors [6, 13], including changes in diurnal temperature [1, 7, 8, 15]. Tolerant species are identified based on the highest annual individual species count and total count (**Table 1**). Top


#### **Table 3.**

*Result of analysis of variance (ANOVA).*


**175**

*Assemblage of Gastropods in the Rocky Intertidal Zone of Asry Beach, Kingdom...*

tolerant species include *C. selectum* with increasing annual population of 1025 in 2016, 1221 in 2017, and 2231 in 2018 (total of 3481); *L. attenuatum* (2016 = 156; 2017 = 148; and 2018 = 167; total = 471); *Turbonilla* sp. 1 (2016 = 68; 2017 = 71; and 2018 = 81; total of 226). Results imply that these species have higher level of tolerance to temperature changes. The mean temperatures vary annually. In 2016, the mean monthly temperature ranged from 18 to 36°C; 17 to 37°C in 2017; and 18 to 36°C in 2018. Hence, the mean temperature in **Table 4** shows fluctuating monthly temperatures with annual mean temperature of 27.75°C in 2016 and

5543 461.917 11776022.917

**Variables Sum Mean SS n r** *p***-valuens** Aerial temperature (°C) 333.99 27.832 508.163 12 −0.0231 **.**943438

Statistically, result of Pearson r coefficient of correlation in **Table 5** shows a negative correlation (r = −0.0231). It means that temperature changes exert no effect on the total count of gastropod assemblage. The *p*-value of .943438 means not significant at *p* < .05. The identified assemblage of gastropods in the rocky zone of Asry Beach constitutes a stable community structure which means that aerial temperature has insignificant effect (*p*-value = .943438, not significant at *p* < .05) on the population of gastropods although the rocky habitat is exposed to diurnal sun lit. In some related studies however [16], correlation analysis revealed a significant positive correlation between the physical factors such as temperature, salinity, pH and DO in diversity of gastropods in the coastal waters of Ambon Island, Indonesia. Temperature as a factor in the related study refers to water temperature considering the type of substrate where the gastropods were sampled. Hence different from the emergent rocky habitat where the gastropods abound on

Asry Beach in the Kingdom of Bahrain is typically an intertidal ecosystem characterized by both sandy and rocky substrate. As a public beach, visitors and other beach goers prefer the sandy portion rather than the rocky part. The rocky zone remains undisturbed where macroflora/fauna community contributes in the coastal food chain and in other ecological interactions. The emergent wet rock surfaces and crevices promote massive algal growth which serves as the feeding ground for many macrofaunal communities. Marine gastropods as natural inhabitants in the rocky biota are tolerable to changes in aerial temperature, thus maintains the dynamics in the rocky shores and ecological balance in beaches. The over-all status of diversity and individual species distribution determine the impact of both the biotic and abiotic factors on gastropod assemblage. Periodic biodiversity assessment and monitoring are initiatives for the protection, preservation and conservation of the

*DOI: http://dx.doi.org/10.5772/intechopen.87772*

28.25°C in 2017 and 2018.

Total species of gastropod assemblage

**Table 5.**

*ns, not significant @ p < .05.*

*Result of Pearson r coefficient of correlation.*

rock surfaces and crevices (**Figure 2**).

natural habitat of gastropods.

**4. Conclusions**

#### **Table 4.**

*Summary of mean aerial temperature (in °C), January 2016–January 2018.*

*Assemblage of Gastropods in the Rocky Intertidal Zone of Asry Beach, Kingdom... DOI: http://dx.doi.org/10.5772/intechopen.87772*


#### **Table 5.**

*Invertebrates - Ecophysiology and Management*

*3.3.2 Statistical analysis on the annual species assemblage*

*3.3.3 Effect of aerial temperature on the total assemblage of gastropods*

Within treatments 3912380.7097 90 43470.8968

Total 3915034.2796 92

*ns = means not significant at p < 0.05.*

*Result of analysis of variance (ANOVA).*

**Table 3.**

**Month Mean annual aerial temperature (in °C)**

*Summary of mean aerial temperature (in °C), January 2016–January 2018.*

**2016 2017 2018**

January 18 19 18 **18.33** February 19 17 20 **18.67** March 23 21 25 **23** April 26 28 27 **27** May 32 33 32 **32.33** June 34 35 36 **35** July 36 37 36 **36.33** August 36 37 36 **36.33** September 34 35 35 **34.67** October 29 31 31 **30.33** November 25 26 25 **25.33** December 21 20 18 **19.67** Mean **27.75 28.25 28.25 28.08**

**Year Mean**

Although the total annual assemblage is high (**Table 1**) statistical analysis using one-way analysis of variance (ANOVA) revealed insignificant differences in the total annual population of gastropod species (**Table 3**). Results imply stability of gastropod species assemblage due to availability of food resources to support community structure [9]. Wet rocky biota promotes massive algal growth which serves as feeding ground for gastropod species [5]. Individual gastropod species only compete for space [6], be it on the rock surface or crevices. Although gastropods are motile, they tend to move slowly thus preventing them from moving in and out of the intertidal ecosystem as a consequence of short period of tidal change [12]. These attributes explain the stability of gastropod assemblage in this particular biota.

Gastropods are adapted to various environmental factors [6, 13], including changes in diurnal temperature [1, 7, 8, 15]. Tolerant species are identified based on the highest annual individual species count and total count (**Table 1**). Top

**Source SS df MS** *F***-value** *p***-value** Between treatments 2653.5699 2 1326.7849 0.03052 **.**96995ns

**174**

**Table 4.**

*Result of Pearson r coefficient of correlation.*

tolerant species include *C. selectum* with increasing annual population of 1025 in 2016, 1221 in 2017, and 2231 in 2018 (total of 3481); *L. attenuatum* (2016 = 156; 2017 = 148; and 2018 = 167; total = 471); *Turbonilla* sp. 1 (2016 = 68; 2017 = 71; and 2018 = 81; total of 226). Results imply that these species have higher level of tolerance to temperature changes. The mean temperatures vary annually. In 2016, the mean monthly temperature ranged from 18 to 36°C; 17 to 37°C in 2017; and 18 to 36°C in 2018. Hence, the mean temperature in **Table 4** shows fluctuating monthly temperatures with annual mean temperature of 27.75°C in 2016 and 28.25°C in 2017 and 2018.

Statistically, result of Pearson r coefficient of correlation in **Table 5** shows a negative correlation (r = −0.0231). It means that temperature changes exert no effect on the total count of gastropod assemblage. The *p*-value of .943438 means not significant at *p* < .05. The identified assemblage of gastropods in the rocky zone of Asry Beach constitutes a stable community structure which means that aerial temperature has insignificant effect (*p*-value = .943438, not significant at *p* < .05) on the population of gastropods although the rocky habitat is exposed to diurnal sun lit. In some related studies however [16], correlation analysis revealed a significant positive correlation between the physical factors such as temperature, salinity, pH and DO in diversity of gastropods in the coastal waters of Ambon Island, Indonesia. Temperature as a factor in the related study refers to water temperature considering the type of substrate where the gastropods were sampled. Hence different from the emergent rocky habitat where the gastropods abound on rock surfaces and crevices (**Figure 2**).
