3.2. CAB Alpha diversity
From the bacterial diversity Shannon (’H’) indices for the five copepod genera, Calanus spp. showed the maximum (Median, (Q1-Q3): 5.85, 4.58-6.29) abundance and evenness of CAB, followed by Centropagessp. (5.13, 4.81-5.41) and, the least was observed in Temora spp. (2.62, 2.36-2.89) (Figure 1a).
The Kruskal-Wallis analysis revealed that the H index of the CAB within the Acartia spp. was significantly different from the CAB ofCalanus spp., Centropages sp., Temora spp. andPleuromamma spp. with a p-value ranging between 0.000002 to 0.023779 (Figure 1a). The H index of the CAB within the Temoraspp. was significantly different from the CAB of Centropages sp. (p=0.0012) and Pleuromamma spp. (p=0.000209). The H index of the CAB within the Calanus spp. was significantly different from the CAB of Centropages sp., Pleuromamma spp., andTemora spp. with a p-value ranging between 0.000008 to 0.05.
Evenness in the indices showed that CAB of the Calanus spp. (0.82, 0.67-0.86) have high evenness index followed byCentropages sp. (0.74, 0.71-0.77) Pleuromamma spp. (0.73, 0.57-0.82), and least in Temora spp. (0.65, 0.51-0.68) (Figure 1b).
The Kruskal-Wallis analysis of CAB evenness index was calculated for all the copepod genera (pairwise). There was a significant different evenness (with p-value ≤ 0.05) between the CAB within Calanusspp. and Acartia spp., Pleuromamma spp., and Temoraspp. Besides, Centropages sp. was significantly different fromTemora spp. (Figure 1b). The Faith’s Phylogenetic Diversity (Faith’s_PD) index of the CAB was maximum in the Pleuromammaspp. (50.75, 16.41-73.45) and the CAB of Temora spp. had less Faith’s_PD, (3.59, 2.45-7.26), respectively (Figure 1c).
The variation in the Faith’s_PD index of CAB was assessed by Kruskal-Wallis test, which revealed that different copepod genera had highly significant and phylogenetically distinct bacteriobiome (Figure 1c). Only the CAB within Acartia spp. was not significantly different from Centropages sp..