UPV Digital RepositoryUPV-DRUniversity of the Philippines Visayas
 

UPV Theses and Dissertations

Permanent URI for this communityhttps://hdl.handle.net/20.500.14583/10

Browse

Filters

1989 - 198912000 - 20032

Settings

AGROVOC Keyword: search.filters.agrovoc.seawater

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    The effect of common table salt added in different levels of water salinity as culture medium on growth and survival of prawn larvae Peneus monodon Fabricius
    Abeto, Mario N. (College of Fisheries, University of the Philippines in the Visayas, 1989-09)
    A study was conducted on the effect of common table salt added in waters of different salinity levels used to determine the survival rate, developmental stage, and carapace length of Penaeus monodon larvae from zoea one to post larva one. The following treatments which were adjusted to 33 ppt by adding varying amount of common table salt were: treatment I (8 ppt + 29 g/l) , treatment II (13 ppt + 23 g/l) , treatment III (18 ppt + 17 g/1), treatment IV (23 ppt + 11 g/1), and treatment V (28 ppt + 5/g) . Natural seawater with salinity of 33 ppt was used as control. Certain key ions like Na+, CL-, Ca2+, and Mg2+ were analyzed in each treatment. A sharp drop of. population in all treatments was recorded in the first 5 days of the zoeal stage. Treatment V gave the highest survival rate (25%) , but not significantly higher than treatment IV (20.5%) and control (18%); however, significantly higher than treatment III (10.5%) and treatment II (6.5%) at P<0.05. None of the larvae survived in treatment I after 5 days. Larvae exposed to treatment V had completed post larva one in 11 days (growth index 7). This was not significantly different, however, from those obtained from the control (growth index 6.6) and treatment IV (growth index 6.3). The lowest growth index value which was significantly lower than treatment V was obtained from treatment II and treatment III (growth index 6.0). During the first sampling, carapace length in treatment I reached 0.47 mm, succeeded by the following treatments: III (0.43 mm) , II (0.42 mm) , and V (0.40 mm). Treatment IV and control gave similar results (0.30 mm). After 2 days, rate of increase of CL had shifted from lower to high ionic concentrations culture media. At the end of the study the following carapace lengths were obtained: 1.2 mm for treatment V, 1.15 mm for control, and 1.08 mm for treatment IV. Values obtained from treatment II (0.94 mm) and treatment III (0.98 mm) were significantly lower than treatment V (1.15 mm) . Rearing waters with higher concentrations of K+ and Mg2+ (control, treatments I, and II)showed better growth rate and percent survival than those media with relatively lower concentrations (treatments I, II, and III) . The addition of common table salt to low saline waters, however, did not compensate for the loss of physiologically important ions needed for growth and survival of prawn larvae.
  • Thumbnail Image
    Item
    Ingestion rate of Charybdis feriatus zoea on Brachionus and Artemia nauplii
    Abarca, Jinky G. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-04)
    A study was conducted to determine if presence of Brachionus will affect ingestion of Charybdis feriatus larvae on the Artemia and to find out the rate of ingestion with increasing density of Artemia. The experiment was conducted using 10-ml capacity vials filled with 6 ml of seawater (26-30 ppt). Increasing densities of Artemia were prepared (0.5, 2.5, 5.0, 10.0, and 20 ind/ml). In one set-up, Brachionus (15 ind/ml) was added. In another set, Brachionus was absent. Another set-up for Artemia with and without Brachionus was prepared but without Charybdis feriatus larvae which served as the control. There were five replicates per treatment. The amount of food prey (Brachionus and Artemia) ingested is determined after 24 hours of feeding on the first day of every zoeal stage (Zl, Z2, Z3, Z4, and Z5). The number of prey ingested by the crab larvae was then calculated. The prey organisms left in containers were then examined under the microscope for missing body parts. The results showed a trend of increasing ingestion rate with increasing Artemia density. This is observed both in treatments with and without Brachionus. The ingestion rate of C. feriatus larvae on the rotifer Brachionus plicatilis showed no trend. However, in zoea 1, there was a trend of increasing ingestion on Brachionus as the feeding density increases. And in zoea 5, it was seen that there is decreasing ingestion on Brachionus as the feeding density increases. There is a trend of increasing ingestion rate on Artemia nauplii as the Charybdis feriatus larvae grow from zoea 1 to zoea 5. There is also a trend of increasing number of observed Artemia with missing body parts as the Charybdis feriatus larvae grow from zoea 1 to number of zoea 5. In addition, there is an increasing number of observed Artemia naupliii with body parts partially ingested as feeding density increases. The presence or absence of Brachionus shows no significant effect on the ingestion on Artemia at low feeding densities (0.5, 2.5, 5 and 10 ind/ml) in all zoeal stages. However, at high feeding densities (20 ind/ml) the ingestion on Artemia is significantly different as seen is zoeal stage 1, 3 and 4.
  • Thumbnail Image
    Item
    Bacteriological analysis of seawater from San Salvador to Belen bay areas in Banate Bay, Banate, Iloilo
    Abancio, Celyn Ann L. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines in Visayas, 2000-04)
    This study was conducted at Banate bay, Banate, Iloilo from a point from Belen to San Salvador. Two samplings were taken one week apart and was analyzed for the Most Probable Number (MPN) per ml coliform count The Multiple fermentation tube technique showed that in Poblacion approximately 100 meters from the shore had the lowest MPN values for both samplings which was >3 MPN per ml. The highest count of greater than or equal to 2400 MPN per ml was obtained in sites Belen-10, Belen-50, and Bularan-10 meters away from the shore. As the distance from the shore increases, the MPN values usually decreases, showing that the area near the shore would exhibit high coliform counts than the are further away from the shore. The tide and the weather may have affected the coliform counts because of the differences of MPN values.