Copepoda

Fernandes, Veronica, Received, Nagappa Ramaiahb, Online, Published & Version, Final, 2019, Spatial structuring of zooplankton communities through partitioning of habitat and resources in the Bay of Bengal during spring intermonsoon, Turkish Journal of Zoology 43 (1), pp. 68-93 : 71-73

3.5. Vertical distribution of Copepoda

3.5.1. Orders

Copepods observed during this study were from four orders: Calanoida , Cyclopoida , Mormonilloida , and

Biovolume (mL 100 m-3)

-240 -120 0 120 240 -240 -120 0 120 240

-240 -120 0 120 240

ng

-240 -120 0 120 240 Harpacticoida , in decreasing order of abundance ( Figure 8 ). Copepods of the order Calanoida averaging 36%–64% of the total copepod abundance in the central bay and 45%–76% in the western bay were at a minimum in the 200–300 m stratum. This coincided with the increased abundances of mormonilloid copepods (31%) in this stratum. Cyclopoida abundance averaged 30% in the water column with relatively higher abundance in the thermocline in the western bay. Harpacticoid percentage was negligible.

3.5.2. Families

From the 34 families of copepods that were recorded during this study, individuals of only eight families ( Clausocalanidae , Eucalanidae , Lucicutiidae , Metridinidae , Paracalanidae , Oithonidae , Mormonillidae , and Oncaeidae ) were dominant during this study. Copepods from 25–30 families were found in the first two strata compared to just 20–24 in the last two strata ( Table 3). In general, Clausocalanidae , Paracalanidae , and Corycaeidae were abundant in the top 200 m and Oncaeidae in all three strata. Copepods from the families of Oithonidae , Metridinidae (in the central bay), and Sapphirinidae (in the western bay) peaked in the thermocline. Mormonillidae was dominant at 200–300 m and Eucalanidae (central bay) and Lucicutiidae (western bay) proportions increased with depth.

3.5.3. Genera and species

Copepods from 50 genera were identified in the central bay ( Table 3), of which 42 each were present in the mixed layer and the thermocline and just 28 in the 200–300 m stratum. The number of copepod species found in these strata was 72, 61, and 39, respectively. In the western bay, 59 genera were identified ( Table 3) with 48 genera each in the mixed layer and thermocline, 33 in the 200–300 m

Biovolume (mL 100 m-3)

-40 -20 0 20 40 -40 -20 0 20 40

)

m

(

strata -700 -350 0 350 700 -700 -350 0 350 700 Depth *

stratum, and 31 in the 300–500 m stratum. The number of species in each of these strata was 80, 84, 49, and 37, respectively.

Figures

Figure 8. Vertical distribution of the various types (orders) of copepods in the central (a) and western (b) Bay of Bengal during the spring intermonsoon. The percentages at every depth are averages from 5 stations in the central and 4 stations in the western bay. Data are unavailable at 300–500 m in the central bay due to negligible abundance.