4.2. ANCOM analysis
In an early report, bacterial members belonging to the
Gammaproteobacteria followed by members of Alphaproteobacteria were
observed to be dominant in Calanus finmarchicus[10]. But, in the present ANCOM analysis, the high
percentile of Gamma and Alphaproteobacteria were equal in number (three
genera each) in Calanus spp. (Figure 3). Similar to our results,
the unclassified genus of Rhodobacteraceae was reported to be abundant
in Acartia longiremis [10]. Colwelliaceae
was reported to be abundant in Calanus finmarchicus[10], but, in the present analysis, order
Colwelliaceae was found to be in high percentile inCentropages sp. An abundance of Flavobacteriaceae was observed
along with phytoplankton and diatoms in the gut ofCalanus finmarchicus with
food [2] whereasSedinimicola sp.
(Flavobacteriaceae) was observed to be dominant in Acartia
longiremis ., Calanus finmarchicus and Centropageshamatus [10]. Also, Dorosz et al.[48] reported that Flavobacterium was more
dominant in Temora longicornis than Acartia tonsa ,
whereas, in our case, Flavobacteriaceae was found to be in high
percentile in Calanus spp.. On comparing, the present ANCOM
analysis and previous reports, Pseudoalteromonas sp. appeared in
high percentile not only within Centropages sp. and inCentropages sp. [10] but also consistent
and abundant bacteria in Acartia sp., and Calanus sp.[10]. As for as, the prevalence ofPseudomonas has been observed in Pleuromamma spp.[11], whereas this was not the case in our
analysis (Figure 3). Similarly, Cregeen [11]analysed the bacteriobiome of Pleuromamma sp. and observed the
dominance of Alteromonas , but, from our meta-analysis, a high
abundance of Alteromonas was observed in Centropages sp.
when compared to five other genera including Pleuromamma spp.
(Figure 3).
From our analysis, Nitrosopumilus was observed to be high inTemora spp., but the Nitrosopumilus abundance was reported
to have no difference between the particle-associated in the water
column and within Temora spp. [38], so the
high percentile observed in our analysis may be due to the exchange ofNitrosopumilus from seawater. The Vibrionales was identified as a
core member in the gut of Pleuromamma spp.[1], which is similar to the present analysis,
i.e. Vibiro percentile was found to be high in the CAB ofPleuromamma spp. The copepods were reported to have a selective
niche of Vibrio that had capability of degrading chitin[1, 49]. In the present analysis, seven bacterial
taxa were found to be in high percentile in Centropages sp. and,
among those seven, four taxa belong to the Gammaproteobacteria. A high
proportion of Gammaproteobacteria in Centropages sp. was also
reported earlier [10].