Zooplankton distribution in coastal water of the North-Western Bay of Bengal, off Rushikulya estuary, east coast of India

546-561<span style="font-size:9.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="" lang="EN-US">In total, 186 species of holoplankton and 23 different types of meroplankton were encountered during this study. Zooplankton community was dominated by copepods represented by 112 species, belonging to 4 orders and 26 families. Calanoida emerged as the most dominant order among the copepods being comprised of 68 species. It was followed by poicilostomatoids with 26 species, cyclopoids with 10 species and harpacticoida with 8 species. Paracalanus aculeatus emerged as the most dominant species during pre-monsoon season while, Acrocalanus<span style="mso-bidi-font-style: italic"> longicornis was dominant in monsoon and A. gibber in the post-monsoon season. Other dominant copepods were <i style="mso-bidi-font-style: normal">Oithona sp., Miracia efferata, Acartia southwelli, Centropages tenuiremis, Paracalanus parvus, <i style="mso-bidi-font-style: normal">Acrocalanus gracilis and Acartia erythraea<span style="font-size:9.0pt;line-height:115%; font-family:" times="" new="" roman";mso-fareast-font-family:calibri;mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="" lang="EN-US">. Average zooplankton density ranged from 2387<span style="font-size:9.0pt; line-height:115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="" lang="EN-US"> org./10m3  to 11659 org./10m3. Zooplankton volume ranged from 0.65<span style="font-size:9.0pt; line-height:115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="" lang="EN-US"> ml/10m3 in monsoon to 1.51 ml/10m3 in post-monsoon season<span style="font-size:9.0pt; line-height:115%;font-family:" times="" new="" roman";mso-fareast-font-family:calibri;="" mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="" lang="EN-US">.<span style="font-size:9.0pt; line-height:115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="" lang="EN-US"> <span style="font-size:9.0pt; line-height:115%;font-family:" times="" new="" roman";mso-fareast-font-family:calibri;="" mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa;mso-bidi-font-style:italic"="" lang="EN-US">Despite high species abundance during premonsoon period,<span style="font-size: 9.0pt;line-height:115%;font-family:" times="" new="" roman";mso-fareast-font-family:="" calibri;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-US"> species diversity was maximum in monsoon. Species richness and dominance indices remained higher during post-monsoon whereas Pielou’s evenness (J’) was more in monsoon. Non-metric multidimensional scaling (MDS) ordinations based on Bray-Curtis similarities indicated <span style="font-size:9.0pt; line-height:115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="" lang="EN-US">that species composition was unequal during different months as there was no similarity above 40% level.</span

Seasonal variation of phytoplankton community in Gopalpur Creek: a tropical t idal backwater ecosystem, East Coast of India

622-634Present study consists of phytoplankton community of Gopalpur creek in pre-monsoon, monsoon and post-monsoon season There was a significant seasonal variation in water temperature (<i style="mso-bidi-font-style: normal">p pH varied significantly (p < 0.05) among the stations. Chlorophyll a and phytoplankton density found to vary significantly (p < 0.01) among seasons rather than the stations. A total of 99 phytoplankton species were identified. Diatoms formed 77, dinoflagellates 14, green algae five, blue green algae two and cocolithophore one species. Phytoplankton species composition was found dissimilar in the three seasons. In pre-monsoon Noctiluca scintillans, Thalassiothrix longissima, Odontella sinensis, Thalassionema nitzschioides, Coscinodiscus gigas, Rhizosolenia alata formed the dominant species. In monsoon, Rhizosolenia alata, Pleurosigma elongatum, Melosira sulcata, Amphora coastatum, Rhizosolenia setigera dominated the phytoplankton population. In post-monsoon Odontella sinensis, Rhizosolenia setigera, Coscinodiscus gigas, Thalassiothrix longissima, Noctiluca scintillans, Oscillatoria spp. dominated. Univariate diversity indices showed maximum diversity during post-monsoon. Pielou’s evenness (J’) and Simpson’s dominance have shown little variation among the seasons. </span

Zooplankton community distribution along offshore transects of some Indian estuaries of east coast: A taxonomic investigation during a summer cruise

1781-1791<span style="font-size:9.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="" lang="EN-US">Zooplankton abundance and composition were studied by selecting offshore transects of seven estuaries <i style="mso-bidi-font-style: normal">viz. Pennar, Krishna, Godavari, Gosthani, Rushikulya, Devi and Mahanadi along east coast of India during April, 2011. During the study period, sea surface temperature (SST) varied from 27.9°C to 28.3°C with an average of 28.1°C. Salinity varied from 33.0 to 35.0 PSU with an average of 34.5 PSU.  Different zooplankton groups belonging to 13 phyla were recorded from seven transects. Copepods dominated the community with 50.5 to 96.8%. Calanoids, namely Paracalanus parvus, P. aculeatus, Temora turbinata were common in all the transects studied. <span style="font-size:9.0pt;line-height:115%; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:"times="" roman";mso-ansi-language:en-gb;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa;mso-bidi-font-weight:bold"="" lang="EN-GB">The Shannon’s diversity index (H´) was found highest in Pennar (2.666) and lowest in Godavari transect (1.785). From cluster analysis and non-parametric multidimensional scaling (nMDS), it is observed that the species composition was changing from north to south of the study area. </span