Copepod feeding study in the upper layer of the tropical South China Sea

Abstract

The South China Sea (SCS) is the world's largest marginal sea being notable for vertical mixing at various scales resulting in a sequence of chemical and biological dynamics in surface waters. We investigated the ingestion, gut content, evacuation and clearance rates of copepods collected from six stations (including a South East Asia Time Series station) along a transect line in the tropical of a SCS cruise during September 27, 1999 to October 2, 1999. The goal of the present study was to understand the feeding ecology of copepods in the upper water layers (0-5 m) of the northern SCS during autumn. We measured the gut pigment contents of 33 copepod species by the gut fluorescence method. The gut chlorophyll a values of most small size copepods (\1 mm) were lower than 1.00 ng Chl a individual -1 . The highest gut pigment content was recorded in Scolecithrix danae (7.07 ng Chl a individual -1 ). The gut pigment contents of 33 copepod species (including 70 samples and 1,290 individuals) estimated is negatively correlated with seawater temperature (Pearson correlation r = -0.292, P = 0.014) and is positively correlated with the chlorophyll a concentration of ambient waters (Pearson correlation r = 0.243, P = 0.043). Mean gut pigment content, ingestion and clearance rates (from 80 samples and 1,468 individuals) show that larger copepods ([2 mm) had significantly higher values than medium sized copepods (1-2 mm) and smaller sized copepods. The present study shows that the performance of feeding on phytoplankton was variable in different sized copepod groups, suggesting that copepods obtained in the tropical area of the southeastern Taiwan Strait might be opportunistic feeders.

Autumn community structure in the shallow mixed layer of the subtropical South China Sea reveals a peculiar copepod and zooplankton assemblage

“…Compared with previous studies in the northern South China Sea, the number of identified species is close to that recorded by Tseng et al (2009) who found 33 species from their feeding studies, being lower than that recorded by Tseng et al (2008a) who found 78 species in December and Hwang et al (2007) who found 101 species in October. A higher number of copepod species is recorded with respect to extended sampling area and sampling depth.…”

“…Zooplankton has a great impact on the transfer of energy and nutrients throughout the food web (Turner 2004;Tseng et al 2008dTseng et al , 2009Hwang and Martens 2011). Different zooplankton taxa play different roles with different impacts.…”

Assessment of the fecundity, population growth and fatty acid composition of Apocyclops royi (Cyclopoida, Copepoda) fed on different microalgal diets

“…Before the start of the experiment, the copepods were transferred from the stock culture to the new culture water for a 24‐hr gut evacuation to avoid the effects of resident algal diet (Tseng, Dahms, Chen, & Hwang, ). At the beginning of the experiment, eight ovigerous females were cultured in each replicate beaker with 400 ml of diluted seawater (20 gL −1 ).…”

Ichthyotoxic Cochlodinium polykrikoides red tides offshore in the South Sea, Korea in 2014: III. Metazooplankton and their grazing impacts on red-tide organisms and heterotrophic protists

“…Metazooplankton including copepods, cladocerans, chaetognaths, larvae of invertebrates, and hydrozoans are a major component of the marine ecosystem (Fulton 1984, Kang et al 1996, Uye and Liang 1998, Calbet 2001, Gallienne and Robins 2001, Puelles et al 2003, Kimmel and Roman 2004, Turner 2004, Tseng et al 2009. They are consumers of phytoplankton and heterotrophic protists and are in turn prey for larval fish and other metazoans (Porter et al 1985, Houde and Roman 1987, Turner et al 1988, Stoecker and Capuzzo 1990, Sanders and Wickham 1993, Carlsson et al 1995, Croll et al 2005, Jeong et al 2007, Waggett et al 2008, Lazareva and Kopylov 2011.…”