Preliminary Study on Fish Larvae at Selected Coastal Waters of Sarawak

Abstract

A survey were carried out from April to November 2012 at five study sites namely Teluk Pandan beach, Rambungan beach, Puteri beach, Sampadi Island and Satang Besar Island, Sarawak. This survey was carried out in order to obtain early documentation of fish larvae at selected coastal waters of Sarawak. Seine net (1 mm mesh size) which was pulled by two persons at intertidal zone; and bridle net (0.5 mm mesh size) that was towed by boat at subtidal zone (Sampadi Island only) were used to collect the samples. A total of 2,562 fish larvae which comprise 25 families were obtained from both sampling methods. A total of 16 families of fish larvae were caught by seine net from the intertidal zone. The same number of families was collected at the subtidal zone of Sampadi Island by bridle net. Ambassidae, Clupeidae, Engraulidae and Gerreidae found to be dominant families in the study sites. Clupeidae and Gerreidae shown a wide larval dispersal area because they were collected at all study sites. These findings seem to indicate that the subtidal zone of Sampadi support more species of fish larvae.

Temporal Variations in Abundance and Species Richness of Zooplankton with Emphasis on Ichthyoplankton in the Subtidal Waters of Umm Al-Namil Island, Northwestern Arabian Gulf of the ROPME Sea Area

“…The results of this study showed that the end of the intertidal zone and the start of the subtidal zone is rich in various forms of zooplankton and ichthyoplankton. Therefore, a temporal monitoring is required in order to observe any changes in either physicochemical or biological factors with time (Muhamad and Rahim, 2014;Souza and Junior, 2019). Further elaborated studies are needed along with other subtidal waters of northwestern Arabian Gulf (including Kuwait), considering ichthyoplankton ecology and species composition, feeding ecology of larval fish, zooplankton abundance and species composition, including benthic copepods and pollution.…”

“…These findings could confirm what has been reported about low abundance of ichthyoplankton predators in such coastal areas (Frank and Leggett 1982;1983) as well as food availability (Taggart and Leggett, 1987;Doyle and Ryan, 1989;Souza and Junior, 2019). As for water current and circulation, this study was not concerned about this aspect but coastal waters of bays and islands as in this study, generally do exhibit circulation patterns which enhance retention of the ichthyoplankton stages, as well as affecting the distribution of zooplankton in general (Harden Jones, 1969;Sinclair, 1988;Laprise and Peppin, 1995;Freitas and Muelbert, 2004;Muhamad and Rahim, 2014;Kodama et al, 2018).…”

“…4a). Though statistically significant (Table 4), it seems to be that species richness and total abundance had no clear relationship and that most probably due to our sampling method, relatively small number of samples collected, as well as the limited area of sampling since these organisms drift with water current and can be moved to different places (Harden Jones, 1969;Sinclair, 1988;Laprise and Peppin, 1995;Freitas and Muelbert, 2004;Muhamad and Rahim, 2014;Kodama et al, 2018). These factors would also explain the non-significant relationship between species-richness and abundance (Table 4 and Fig.…”

“…Therefore, this indicates that the planktonic food web is strongly supported by both primary producers and primary consumers. However, ichthyoplankton were absent at events 1, 10 and 12 and that could be attributed to the aforementioned factors by Muhamad and Rahim (2014), Souza and Junior (2019) and Zhang et al (2019). In addition, this also depends on the type of adults present around the study area and their spawning season.…”

“…Other factors affecting larval fish abundance and distribution are water turbidity, tidal cycles and spawning time, as well as food availability and feeding habits (Muhamad and Rahim, 2014;Souza and Junior, 2019;Zhang et al, 2019). This is because meteorological and oceanographic features are often associated with seasonal patterns of abundance of larval fish (Hernández-Miranda et al, 2003;Ndour et al, 2018;Souza and Junior, 2019;Zhang et al, 2019) and it can affect transportation and feeding of larvae by currents (Harden Jones, 1969;Sinclair, 1988;Freitas and Muelbert, 2004).…”