UPV Digital RepositoryUPV-DRUniversity of the Philippines Visayas
 

Undergraduate Special Problem

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/30

Browse

Filters

2003 - 200932010 - 20163

Settings

Adviser: search.filters.advisor.Baylon, Juliana C.SDG: search.filters.sdg.SDG 14 - Life below water

Search Results

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    Gonadal maturation Stages of Pinkfingered Vinegar Crab Episesarma chengtongense (Serene and Soh 1967) from Capiz, Philippines
    Barredo, Elilyn Farrah Belle B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2015-06)
    The pink-fingered vinegar crab Episesarma chengtongense is a growing fishery resource in the mangrove areas of the Philippines and may have potential for aquaculture and stock enhancement. To determine the gonadal maturation stages for both male and female for this species, a study was conducted from February to May 2015 of the pink-fingered crab from Capiz, Philippines. The determination of the gonadal maturation stages was based on the gross morphology and histological characteristics of the male and female gonads. In both sexes, gonad activity occurred throughout the study duration but for females, the peak egg bearing month was in May (87%). Body sizes of ovierous females were from 31.9 - 42.3 mm (CW). The greatest prevalence of ovigerous females was in the size range of 35-39 mm CW; the lowest percentage at 40-44 mm CW. Male crabs with mature testes were consistently high (70- 100%) in the four months duration of the study. The smallest female carrying eggs was 31.9 mm CW. Four stages of ovarian maturation were identified namely: developing (Stage II) with a yellow colored gonad, ripe (Stage III) with orange colored gonad, mature (Stage IV) with brown colored gonad and spent (Stage V) with light brown colored gonad. Two stages of male gondal maturation were identified namely immature (Stage I) with translucent to off white testes and mature.(Stage II) with creamy white testes.
  • Thumbnail Image
    Item
    Gonadal maturation stages of pink-fingered vinegar crab, Episesarma chengtongense (Serene and SOH 1967), from Capiz, Philippines
    Ballon, Shaira B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2016-06)
    Pink-fingered vinegar crab is a nocturnal, burrow-dwelling, and tree-climbing crab that feed on mangrove leaf litters and foliage. This crab is a growing fishery resource in the Philippines and plays an important role in the nutrient cycling in mangrove areas. To determine the reproductive biology of this species, a one-year study was conducted to monitor the gonadal maturation stages of the pink fingered crab from President Roxas, Capiz. Collection of samples was done every first week of the month from February 2015 to January 2016. The determination of the gonadal maturation stages was done through the visual examination of the gross morphology and microscopic examination of the histological characteristics of the male and female gonads. A total of 425 (263 females, 162 males) crabs were dissected. Five stages of ovarian maturation were identified based on visual examination of ovaries, namely Immature (Stage I) with translucent to white colored gonad; Developing (Stage II) with a yellow colored gonad; Ripe (Stage III) with orange colored gonad; Mature (Stage IV) with two substages, the Early mature (Substage A) with brown colored gonad and Late mature (Substage B) with dark brown colored gonad and; Spent (Stage V) with light brown colored gonad. Microscopic examination of the ovaries revealed that ovary in Stage I is characterized by the presence of germinative zone composed of oogonia and maturation zone composed of previtellogenic oocyte, surrounded by randomly distributed follicle cells. Ovary in Stage II is composed of few oogonia, previtellogenic cells, and few endogenous vitellogenic oocyte on the periphery of the ovarian lobe. Ovary in Stage III is composed of dominant exogenous vitellogenic oocyte located outer the few endogenous vitellogenic oocyte. Ovary in Stage IV-A is composed of nearly mature oocyte while in Stage IV-B is composed of mature oocyte. Ovary in Stage V is composed of all cell types, disarrayed in the entire ovarian lobe. Two stages of male gonadal maturation were identified namely Immature (Stage I) with translucent testes that is composed of spermatogonia and spermatocyte when histologically examined and Mature (Stage II) with white testes that is composed of small, darkly staining spermatids. Size of female crab samples ranged from 26 to 48.1 mm carapace width (CW) while male crabs ranges from 26 to 47 mm CW. The smallest ovigerous female has 29 mm CW and the smallest male with mature gonad has 26 mm CW. Body sizes of ovigerous females were from 29 to 42.3 mm CW. The greatest prevalence of ovigerous females was in the size range of 30 to 34 mm CW. The highest percentage of the mature stage (Stage II) in male was in the size range of 45 to 49 mm. For females, the peak egg bearing season was May (87%) and September (92%). On the other hand, male crabs with mature testes were consistently high (70 to 100%) in all months of the year. The results indicated that the months of May and September should be declared off season in the capture of female crabs ranging in size from 25 to 44 mm CW. Only big females in the size range of 44 to 49 mm CW could be harvested. Likewise, also male crabs in bigger size range of 45 to 49 mm CW could be harvested. This is necessary to protect and conserve the existing population of this crab.
  • Thumbnail Image
    Item
    Comparison of the length-weight relationship between starved and fed Scylla tranquebarica crablets
    Arroyo. Ritchel B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-04)
    This study aimed to determine the length-weight as well as the width-weight relationships of the Scylla tranquebarica crablets when starved and fed during the intermolt and premolt stages. Molt stages were identified and then the crablets were subjected to feeding or starvation for 36 days. Regression analysis showed the length-weight relationship of the Scylla tranquebarica crablets, including carapace length, carapace width, and body weight when fed and starved. Regression lines for each category differed from one another. Results showed that the fed crablets in intermolt and premolt stages showed greater body weight gain per unit carapace length and carapace width. The intermolt fed gave the highest weight gain per unit length and unit width among the treatments. Equations for interconversions of length and weight and for length and width are reported for the premolt and intermolt stages when fed and starved.
  • Thumbnail Image
    Item
    Reproductive biology of coconut crab Birgus latro (LINNAEUS 1767) from Antique, Western Visayas, Philippines
    Alberca, Pavi Jewime O. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2016-06)
    The coconut crabs Birgus latro continue to decline globally and are now considered as an endangered species. In order to prevent further depletion of the species, much effort must be placed on implementing municipal ordinances such as seasonal closures and minimum legal size limits. This study aimed to monitor the breeding cycle of the Birgus latro from the islands of Sibolon and Maniquin. Antique. Philippines using macroscopic and microscopic techniques. A minimum of ten crabs were collected every month for six months (Aug. 2015 - Jan. 2016). The crab samples were examined based on the morphological and histological appearance of the gonads. The body weight, thoracic length (TL). cephalothoracic length, carapace width, pleonal expansion, gonad weight and hepatopancreas weight were measured. The gonadosomatic index (GSI), hepatosomatic index (HSI). pleonal expansion index (PEI) and gonad index (GI) were calculated. The results revealed two stages of development for both the male and female B. latro. The testicular stages were a) maturing stage - creamy white with the presence of spermatogonia, spermatids and spermatozoa; b) mature stage - creamy white and larger with the presence of the spermatozoa only. The ovarian stages were a) maturing stage - light yellow with the presence of oogonia, endogenous and exogenous vitellogenic oocytes and follicle cells: b) mature stage - reddish brown and larger with the presence of the fully mature oocytes. The smallest sexually mature crab for the male was 28 mm TL and for the female was 32 mm TL. The mature testes were observed all throughout sampling period, while the mature ovaries were only in August, September and October. The occurrence of the male B. latro was higher than the females. In males, the GSI and GI were directly proportional to the developmental stages. The HSI was inversely proportional. while the PEI showed no relationship. In females, the GSI. HSI. PEI and GI showed a direct relationship with the stages of development.
  • Thumbnail Image
    Item
    Effect of salinity on the embryonic development of Portunus pelagicus and Charybdis feriatus eggs
    Alba, Kristine Margaret A. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2003-03)
    The effect of salinity on the embryonic development of Portunus pelagicus and Charybdis feriatus was studied. The five different salinity levels used were 15 ppt, 25 ppt, 35 ppt, 45 ppt, and control (33-35 ppt) to compare their effect on the embryonic development of both species. One thousand newly spawned crab eggs were incubated in vitro in 4-L Nalgene fiberglass containers with 3-L of water at different salinity levels. Mild aeration that allows movement of eggs within the water column was provided. There were three replicates per treatment. Embryonic development of eggs (30 eggs were taken in every salinity level) was monitored daily up to hatching. The newly hatched larvae were then collected and counted. Results showed that during the incubation period, the most advanced stage of embryonic development for Portunus pelagicus was at 33-35 ppt and for Charybdis feriatus was at 35 ppt. There was normal embryonic development and hatching at 35 ppt, 45 ppt, and control (33-35 ppt) for Portunus pelagicus and at 15 ppt, 25 ppt, 35 ppt, 45 ppt, and control (33-35 ppt) for Charybdis feriatus. Eggs that were incubated at 15 ppt and 25 ppt for Portunus pelagicus died. There was normal embryonic development in both species when incubated at 45 ppt. Hatching rate for Portunus pelagicus at control (33-35 ppt) was 34.1 %, at 35 ppt was 16.1 %, and at 45 ppt was 5.8 %. Hatching rate for Charybdis feriatus at 35 ppt was 52.5 %, at control (33-35 ppt) was 21.2 %, at 45 ppt was 12.8 %, at 25 ppt was 6.7 %, and at 15 ppt was 0.3 %. To summarize, embryo of Charybdis feriatus eggs can withstand a wider range of salinity: from a low salinity of 15 ppt to a high salinity of 45 ppt, that makes them a euryhaline species. On the other hand, Portunus pelagicus cannot support embryonic development at lower salinities of 15 and 25 ppt that makes them a stenohaline species.
  • 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.