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Articles by A. Christianus
Total Records ( 21 ) for A. Christianus
  F.A.H. Nur and A. Christianus
  Neocaridina denticulata sinensis (Kemp, 1918) or also known as red cherry shrimp (RCS) became popular in aquarium industry since its first introduction in 2003 until now. Little is known of this particular species since documented report is very scarce. Thus, this study was conducted to gather some information on its breeding behavior and life cycle until first maturity in laboratory condition. Fertilized eggs were found to be oval in shape with color varies from greenish to yellowish. The egg size was comparatively large, with an average diameter of 1.19 mm. Embryonic development of N. d. sinensis lasted for 15 days at 27°C. Newly hatched larvae look like a miniature version of the adult with an average total length of 2.3 mm. A female can produced about 21-51 larvae per hatching. Larger females produced more larvae. It takes 60 days for larvae to reach juvenile stage, where male and female were still undifferentiated. Juveniles become adults 15 days later. Females were obvious with the presence of orange colored ovary at the cephalothorax region. Within one to three days, these males and females are ready to spawn. During this study, N. d. sinensis cultured in freshwater were found to be susceptible to clitellate annelid (Holtodrilus sp.). Culture of this species in slightly saline condition between 5-10 ppt was an effective treatment for this annelid.
  Sh. Shakibazadeh , A. Christianus and P. Hajeb
  Amoebocytes are the main carrier of innate immune system in horseshoe crabs. Cytoplasm of these cells are packed with granules which consist of all coagulation factors and anti-bacterial compounds. Light microscopy (using May-Grunwald and Giemsa staining technique) of 46 blood specimen for both sexes of Tachypleus gigas and observation under Transmission Electron Microscopy (TEM) were performed. Light microscopy revealed that these are ovoid cells containing blue nucleus surrounded by a cytoplasm packed with pink granules. Large and small axes measured 18.8±0.5 and 12.8±0.4 μm, respectively. Total blood cell count (33000 cell mm-3) does not show any significant difference between sexes. TEM of normal and degranulated blood cells revealed that T. gigas hemocytes consist of two type of granules (large and small). Blood cells have all the necessary organelles of normal cells. During the granule formation, fusion of different intermediate granules were observed. Degranulated hemocytes under light microscope and TEM showed cells containing large nucleus and cytoplasmic granules were replaced with a large cytoplasmic vacuole. In light and electron microscopy only one type of hemocyte was observed, the granular cells. These granular cells consist of large and small granules.
  M.I.M. Faizul , M.M. Faizal , A. Christianus and S.M.N. Amin
  In order to develop suitable methods to successfully hatch Tachypleus gigas eggs, a study was carried out on different salinity and culture media. The main objective for this study was to determine the effect of watering frequency, salinity and media on the incubation period and hatching of T. gigas eggs. This research consisted of three experimental studies. In the first experiment, effect of water salinities (15, 20, 25 and 30 ppt) for watering or moistening sand was studied. For the second study, effect of watering frequencies (once in 1, 3 and 6 days) on the eggs incubated in sand were investigated. As for the last experiment, effect of incubation medium (water and sand) on eggs were compared. Data collected for these experiments were eggs diameter and hatching percentages. Embryonic developments were observed and photographed during the study period. Results from experiment 1, showed that at the end of the incubation period, watering with water salinity of 25-30 ppt produced significantly larger eggs diameter (p<0.05) while percentages of hatching was the highest with 30 ppt water. In experiment 2, it was found that percentages of hatching were significantly higher (p<0.05) when watered once a day and in three days. As for experiment 3, at the end of the incubation period, there was no significant different (p>0.05) in the eggs diameter and percentage of hatching between sand and water medium. In conclusion, the most suitable salinity and watering frequency were 25-30 ppt and once in 3 days, respectively. However, both sand and water are suitable media to successfully incubate T. gigas eggs. Overall, this study showed that T. gigas eggs can hatch as early as 40 days after fertilization.
  K.Z. Intan , A. Christianus , S.M.N. Amin and M. Muhamad Hatta
  The present study investigated the breeding and embryonic development of sebarau, Hampala macrolepidota from fertilization until early hatched. The matured eggs and sperm were obtained by induced breeding using a commercial hormone, ovaprim. Dosages given for female and male were 0.6 and 0.3 mL ovaprim kg-1 b.wt., respectively. Fertilized eggs were adhesive, spherical and sticky. Fecundity for females weighing 180-280 g ranged from 34,985-75,646 eggs/fish. Average diameter of the fertilized eggs ranged from 0.55±0.13-1.06±0.36 mm. Fertilization rates ranged from 18-28% after 24 h incubation. The observation on the embryonic development covers various stages from newly fertilized eggs, cell division, epiboly, somites until hatched.
  M. Hazmadi Zakaria , S.M.N. Amin , M. Aminur Rahman , M. Hatta Mahmud , A. Christianus , S.S. Siraj and A. Arshad
  The present study was carried out to investigate the embryonic and larval development of the endangered Temoleh, Probarbus jullieni in lab-rearing condition. The matured egg and sperm were collected by stripping the bloodstock of Temoleh fish after injecting with ovaprim hormone extract. The samples were collected from hatching tank at every 10 min interval for the first hour, 20 min for the second hour, 30 min for the third hour and then hourly interval up to hatching. After hatching, larvae were observed daily until the complete disappearance of the yolk sacs. The fertilized eggs were spherical, demersal, adhesive and brownish-yellow in colour with a mean diameter of 2316 μm. First cleavage occurred within 10 min post-fertilization at temperature ranged from 26.0 to 28.0°C. Hatching started 22 h post-fertilization and completed within 25 h at the same temperature. The yolk sac was completely absorbed 61 h after hatching. At the same time, the larvae started to swim actively and feed exogenously. This marks the first description on the early life history of P. jullieni. The present study will provide some valuable information on the ontogeny, breeding biology and early larval rearing protocol of P. jullieni which will ultimately be helpful towards the establishment of large scale seed production technique for conservation and aquaculture production.
  L.A. Argungu , A. Christianus , S.M.N. Amin , S.K. Daud , S.S. Siraj and M. Aminur Rahman
  The presence of Asian catfish, Clarias batrachus in Malaysia is at a deteriorating state. It is hardly a cultured species since the supply of seed is unavailable. This species is found in lowland streams, swamp and rice fields. Therefore, they are greatly exposed to factors such as intermittent periods of drought, devastation of the natural habitat and agro-chemicals. Presently, fish farmers are more into the culture of Clarias gariepinus. This threatened the mere existence of this indigenous C. batrachus. Hardiness, good growth, efficient food conversion and excellent nutritional profile guarantee C. batrachus as a suitable aquaculture candidate. Some conservation efforts were looked into in order to prevent the extinction of this potentially important catfish.
  N.M. Azuadi , S.S. Siraj , S.K. Daud , A. Christianus , S.A. Harmin , S. Sungan and R. Britin
  Induced ovulation of captive Malaysian mahseer (Tor tambroides) often encounters low reproductive performances. The present study was conducted to gain insight to problems associated with poor breeding performance of Malaysian mahseer in captivity. In this study, sex steroid hormone levels and ovulation performance in filial 1 (F1) generation of Malaysian mahseer (Tor tambroides) were investigated. Fishes were injected with ovatide, combination of Salmon Gonadotropin Releasing Hormone Analogue (sGnRHa), DOM, sGnRHa+DOM and 0.9% NaCl. A total of 30 matured females T. tambroides with weight ranged from 2.01-3.80 kg were used in this study. The females were given ovaplant (39.5-37.3 μg kg-1) pretreatment for 6 weeks prior to hormones injection. Females were given a single intramuscular injection of ovatide (0.5 mL kg-1 b.wt.), sGnRHa (10 μg kg-1 b.wt.), DOM (5 mg kg-1 b.wt.), sGnRHa+DOM (10 μg kg-1 b.wt.+5 mg kg-1 b.wt.) or 0.9% NaCl. Blood samples were collected at 0, 6, 12 and 24 h (s) after injection. The effect of these treatments on sex steroids level (Testosterone (T) and 17β-Estradiol (E2) and ovulation performance of F1 Tor tambroides were evaluated. Result showed that higher ovulatory response was observed in the group treated with positive control ovatide (0.5 mL kg-1 b.wt.). Interestingly, it was observed that sGnRHa and Domperidone (DOM) produce highest egg and larval qualities compared to ovatide and sGnRHa alone. No ovulation occurred in the group treated with DOM alone. Sex steroids plasma concentration of T and E2 increased significantly in association with ovulation. The levels fluctuated and reached a peak at 12 h, then dropped dramatically at 24 Post Injection (PI). In contrast the non-ovulated groups, the sex steroids hormone concentration showed little increment after injection and rose at 12 h PI, then slowly dropped at 24 h pi. These results provide evidence for a strong dopamine inhibition on GtH secretion in captive mahseer.
  F.A. Adebiyi , S.S. Siraj , S.A. Harmin and A. Christianus
  The aim of this study was to characterize embryonic and larval developmental stages of the river catfish, Hemibagrus nemurus. Fertilized eggs were spherical, adhesive and demersal with a mean egg diameter of 1.5±0.3 mm. Seven embryonic periods were characterized for timing and features: zygote, cleavage, blastula, gastrula, segmentation, pharyngula and hatching. Mean hatch was 23±1 h post fertilization at 27°C. The newly hatched larvae measured 3.0±0.2 mm in total length. Morphogenesis was completed in a day. The yolk sac was completely absorbed in three days. H. nemurus has a short embryonic developmental period in comparison with other catfish species. The information obtained from this study will be useful for egg incubation and larval rearing during the culture of H. nemurus.
  N.M. Azuadi , S.S. Siraj , S.K. Daud , A. Christianus , S.A. Harmin , S. Sungan and R. Britin
  Tor tambroides is an important and highly valued freshwater fish. In Malaysia, wild populations of this species has undergone declines in range and abundance due to degradation of their natural habitat. Due to economic important and concerns about their conservation, a culture artificial propagation programme was established to produced seed-stock for aquaculture and conservation purposes. The effectiveness of selected synthetic and non-synthetic commercial hormones was tested on filial 1 generation (F1) of Tor tambroides (Bleeker 1854) females in captivity. A total of 144 matured females were given intramuscular implantation of slow release hormone, Ovaplant (38.6-53.6 μg kg-1 b.wt.), for 5-6 weeks prior to induction. Selected commercial hormones were compared for the induction. The effect of these hormones on breeding performance and larval quality of F1 Tor tambroides were evaluated. The results showed that Ovatide (0.5 mL kg-1 BW) was the most reliable hormone in inducing ovulation of F1 T. tambroides females overshadowed the other tested hormones. Ovaprim (0.5 mL kg-1 b.wt.) was the next best tested hormone followed by a synthetic analogue of salmon gonadotropin releasing hormone (sGnRHa/OvaRH) (10 μg kg-1 b.wt.). No ovulation occurred in the groups treated with Luteinizing Hormone Releasing Hormone Analogue (LHRHa) (10 μg kg-1 b.wt.), Human Chorionic Gonadotropin (HCG) (1000 μg kg-1 b.wt.) and Carp Pituitary Extract (CPE) (10 mg kg-1 b.wt.). Ovatide was further chosen to test its effectiveness at various dosage levels in inducing ovulation of T. tambroides. Thus, concentration of 0.5 mL kg-1 b.wt. of Ovatide was found to be the optimum dosage for inducing ovulation of F1 T. tambroides in captivity.
  N.M. Azuadi , S.S. Siraj , S.K. Daud , A. Christianus , S.A. Harmin , S. Sungan and R. Britin
  The study was conducted to observed the embryonic development, morphology of eggs, newly hatched larve and post larval of the filial 1 (F1) generation of Malaysian mahseer, Tor tambroides using hatchery-reared specimens. The first cleavage occurred at 2 h after fertilization (HAF), epiboly began at 11 HAF, the embryonic body was formed at 22 HAF and hatched at 76 HAF. The mean total length of newly hatched larvae was 7.44±0.06 mm and almost has similar external features to other Tor species. The mouth and foregut opened at 7th Day after Hatching (DAH) with the mean total length of 12.8±0.11 mm. Tor tambroides reached 13.2±0.15 cm of total length and 31±0.53 g of body weight at 10 months of age. The induced ovulation technique using newly developed commercial synthetic hormone, Ovatide have paved the way for further development and improvement of culture production of the Malaysian mahseer.
  N.M. Azuadi , S.S. Siraj , S.K. Daud , A. Christianus , S.A. Harmin , S. Sungan and R. Britin
  Natural spawning ground of most Malaysian streams are undergoing extreme changes as a result of human activities, pollution and climate change (extreme temperature fluctuation) which lead to dramatic decrease in mahseer (Tor tambroides, Cyprinidae) populations. An experiment was conducted to evaluate the effectiveness of salmon gonadotropin releasing hormone analogue (sGnRHa) alone or in combination with dopamine antagonist domperidone (DOM) on breeding performances of female breeders. Sixty females T. tambroides ranging in weight 2.01 to 3.96 kg while thirty males with average weight 1.38 to 1.72 kg were used in this study. The females were given pretreatment with Ovaplant (23.4-44.9 μg kg-1) for 6 weeks prior to induction. Females were tested with various treatments such as Ovatide, sGnRHa, sGnRHa+DOM and DOM. SGnRH analogue alone does not contain dopamine antagonist to block dopaminergic inhibition action. Females were given single intramuscular injection of Ovatide (0.5 mL kg-1 BW), sGnRHa (10 μg kg-1 BW), sGnRHa+DOM (10 μg kg-1 BW+5 mg kg-1 BW) or DOM (5 mg kg-1 BW). The control group was administered with 0.9% NaCl. The fish did not spawn spontaneously but through hand stripping to release eggs. Results showed that Ovatide significantly produced highest ovulation rate, total stripped eggs and stripped fecundity. Interestingly, we observed that broodstock groups injected with sGnRHa+DOM produced highest fertilization, hatching and survival rates compared to other treatments. Good egg and larval quality were recorded in the group treated with sGnRHa+DOM. No females ovulated in the group receiving DOM alone and saline solution. The combination treatment was found to be more potent in inducing ovulation as compared to sGnRHa alone or DOM alone. Our results suggest that dopaminergic inhibition is a major barrier in inducing spontaneous spawning in captive mahseer and we successful produced progeny generation of T. tambroides larvae.
  N.A. Muhammad , A. Christianus , S.K. Daud , C.R. Saad , S.A. Harmin and M.Y. Ina-Salwany
  Vitellogenin (vtg) is a high molecular weight glycophospholipoprotein synthesized in the liver under stimulation of estrogen. Basically found in sexually mature female, vtg being taken up by developing oocyte during maturation. It functioned as a nutrient storage for growing embryo. Having potential to be used as a maturation indicator, vtg helps to enhance fish fry production. Tor tambroides is one of the most sought after fish in Malaysia for having potential as a game fish yet so important economically due to high demand by farmers as well as consumers. Main problem in the mass production of T. tambroides fry in hatchery is in the availability and selection of matured broodstock. Identification of matured and ready females morphologically can only be done by experience workers. Therefore, establishment of simple technique to definite identify matured females is necessary. This has led to the identification, purification and development of enzyme linked immunosorbent assay (ELISA) to measure blood plasma vtg as maturation indicator. This will definitely contribute to the hatchery production of T. tambroides fry.
  H. Abdi , A. Christianus , E. Ramezani- Fard , C.R. Saad and S.A. Hosseini
  Catfish species are popular fish group consumed in Malaysia. African catfish, Clarias gariepinus and Asian redtail catfish, Hemibagrus nemurus are two of these catfish species. Unfortunately, some parts of these fish are removed during processing. This includes the liver which contained considerable amount of extractable lipid with both monounsaturated and polyunsaturated fatty acids. The fish samples were purchased and transported in ice box to the laboratory. Liver was extracted and analyzed for crude protein, crude lipid, moisture, ash, carbohydrate contents and fatty acid composition. Results were compared between male and female C. gariepinus and H. nemurus. Liver of female H. nemurus contained the highest amount of ash, crude lipid and carbohydrate and the lowest amount of moisture. Male H. nemurus had the lowest amount of protein, ash and crude lipid content. Moisture was found to be the highest in male C. gariepinus. The main fatty acid content of Asian redtail catfish and African catfish liver were C12:0, C14:0, C15:0, C16:0, C16:1, C17:0, C18:0, C18:1n-9, C182n-6, C183n-3, C204n-6, C24:1, C205n-3, C225n-3, C226n-3. The most abundant fatty acids in both species were oleic acid (18:1n-9) and palmitic acid (16:0). In conclusion, this study showed that H. nemurus and C. gariepinus, are two valuable source of protein and polyunsaturated fatty acid.
  M.I. Mohamad Faizul , A. Christianus , S.M.N. Amin , S. Shafeeqa and T. Rishzuan
  Information on the growth of Tachypleus gigas is not well established as compared to its temperate counterpart Limulus polyphemus. Lack of documented study on T. gigas has further encouraged research on the growth and molting frequency under different culture methods. This report compares the size and weight increments and molting frequency of T. gigas larvae cultured using conventional (80-90% water change/day) and non-conventional (recirculating aqua culture system) methods. Size increment was measured based on prosomal width and weight increments of the larvae. Molting frequency was determined for the larvae from 6 to 11-month old. The larvae culture using these two methods molted 3 times during the culture period. Result of t-test showed that there was no significant differences (p>0.05) in the molting frequency of the larvae between the two methods. The final prosomal width for T. gigas larvae cultured using conventional method was 23.50 mm which is significantly (p<0.05) smaller as compared to 27.99 mm using non-conventional method. Similarly the final weight of the 11-month-old larvae cultured using conventional method was 0.61 g which is comparatively lower than those cultured under recirculating aqua culture system, 0.92 g. Water parameters (pH, salinity, temperature, dissolved oxygen and ammonia) for both systems were monitored and it was found that the conventional and non-conventional method of culture does not differ in salinity, temperature and pH except for dissolved oxygen (DO) and ammonia.
  I.S. Kamaruddin , A.S. Mustafa- Kamal , A. Christianus , S.K. Daud , S.M.N. Amin and L. Yu- Abit
  The Length-weight Relationship (LWR) and condition factor (K) of three most dominant species from the Tasik Kenyir was evaluated from February 2008 to January 2009. The data were analyzed by the equation of W = aLb and were transferred to Log10W = Log10 a + b Log10 L, for the length-weight relationship and K = W x 100 L-3 for the condition factor. The relative growth coefficient (b) values for Barbodes schwanenfeldii was 2.784, Notopterus sp. was 1.905 and Hampala macrolepidota was at 3.043. The condition factor values varied seasonally for each species that range from 2.48±0.39 to 2.68±0.28 for B. schwanenfeldii, 0.95±0.10 to 1.03±0.20 for Notopterus sp. and from 2.17±0.19 to 2.35±0.39 for H. macrolepidota.
  I. Zalina , C.R. Saad , A.A. Rahim , A. Christianus and S.A. Harmin

Anabas testudineus was successfully induced to spawn using LHRHa. Egg production, hatching rate and GSI were 5126 eggs/fish, 62 and 10.41%, respectively. Results showed that the survival and growth of A. testudineus during the 30-day nursing period were stocking density dependent. The highest survival rate was recorded in T1 (35/L; 75%), followed by T2, (55/L; 53%) and lastly T3 (75/L; 43%). The weekly growth performance in T1 (35/L), in terms of total body length and body weight was significantly better than other treatments, especially after 21-day of nursing. Fish larvae were fed with a combination of live and prepared foods. Water quality parameters were stable and not influenced by the stocking densities tested.

  I. Zalina , C.R. Saad , A. Christianus and S.A. Harmin
  This study described the induced breeding and embryonic stage of Anabas testudineus using commercial hormone LHRHa with the intensity level of 2, 20, 200 μg kg-1 of body weight, respectively. It was found that all intensity of LHRHa hormone level could enhance the fish to breed with the exception of the control group. Fertilization rate, hatching rate, latency period, fecundity, oocytes diameter and GSI were quantified in each set of experiment. It was observed that the fertilised eggs of A. testudineus were almost spherical in shape, clear pearl likes in appearance and free floating on water surface. Fecundity and GSI were significantly higher in fish treated with 200 μg kg-1 as compared to fish treated with 2 and 20 μg kg-1 of body weight of LHRHa hormone. There was no significant (p>0.05) effect between hormone level on fertilization rate, hatching rate and eggs diameter. The diameters of fertilised eggs ranged from 800-850 μm. The first cleavage occurred at 1:30 h, epiboly began at 5 h, the embryonic body was formed at 12 h and hatching occurred at 20 h after fertilization at water temperature of 26°C. Newly hatched larvae were approximately 0.6-1 mm (total length) and pigment spots were present over the yolk and head. The embryonic development of the fish is described. The present study indicated that the administration of LHRHa hormone is effective for ovulation and hormone level at 2 μg kg-1 is recommended.
  M.I.M. Faizul and A. Christianus
  The effect of salinity and stocking density on the growth and survival of Barbodes gonionotus fry were studied. Experiments were carried out at the Aquaculture Research Station Puchong, Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, Serdang, Selangor. Parameters measured once a week were total length (cm), weight (g) and survival (%). Water quality such as dissolved oxygen (DO), pH, ammonia, nitrite and temperature were monitored once in two days prior to the water change. During the study period, fry were fed ad libitum with commercial pellets (Star Feed with 42% Crude protein), two times daily at 09:00 and 17:00 h. In the first experiment, 2 cm B. gonionotus fry were used and place in 6 glass aquarium (58x38x38 cm). Fry were cultured at three stocking densities, 3, 5 and 8 fry L-1. At the end of culture period, it was found that B. gonionotus fry stocked at 3 fry L-1 showed significantly higher (p<0.05) final weight and total length. However, stocking density of 5 fry L-1 resulted the highest percentage of survival at the end of the experimental period. In the second experiment, B. gonionotus fry were cultured in water with four different salinities, 0, 5, 10 and 15 ppt. Similarly, 2 cm fry were used and placed in 6 glass aquariums (58x38x38 cm) with 40 L water. Treatment with 15 and 20 ppt were terminated due to mass mortality between 3-7 days of exposure. As for the rest of the treatments, it was found that B. gonionotus fry cultured at 0 ppt showed significantly higher (p<0.05) final body weight and total length as compared to 5 and 10 ppt. However, by the end of the experimental period, the percentage of survival was significantly the highest at 10 ppt. This study showed that B. gonionotus fry can be stocked at 3 fry L-1 without adverse effect on its growth and survival and survive well at 10 ppt.
  L.A. Argungu , A. Christianus , M.S.N. Amin , S.K. Daud and S.S. Siraj
  Malaysia is one of the countries in Asia with higher scarcity of Clarias batrachus. Consequently, to arrive at better ways of handling the situation the reproductive endocrinology of the species was investigated. Testosterone (T), 11-ketotestosterone (11KT) and 17β-estradiol (E2) were the plasma sex steroid hormones monitored monthly throughout the reproductive cycles. Several peak levels were observed in the annual profiles of all the steroid hormones, implying that C. batrachus is a non-seasonal breeder, signifying that the species could spawn several times during the reproductive cycle. Most of the scholars who earlier worked on the breeding of this fish concentrated on a particular period (May to August) assuming that was the only season successful induced breeding of the species could be achieved. The present study has enhanced the understanding of the reproduction of C. batrachus. It has provided a platform for the optimization of reproduction and breeding program of the species.
  M. Hazmadi Zakaria , S.M.N. Amin , M. Aminur Rahman , A. Arshad , A. Christianus and S.S. Siraj
  The freshwater fish, Probarbus jullieni (Sauvage), locally referred to as “Temoleh”, is a high-valued freshwater fish in Malaysia and has both cultural and conservational significance. It is widely distributed in the North-east Asian countries such as Thailand, Cambodia, Vietnam and Malaysia. During the recent past, the natural stocks of P. jullieni have been decreased severely due to habitat degradation and man-induced hazards in aquatic ecosystem. Despite the vast research that has been conducted on various carp species, little attention has been given to P. jullieni. This study reviewed the published information on the status, distribution, reproduction and biodiversity of this commercially important fish species. The findings would greatly be helpful towards the species conservation and aquaculture development of the highly endangered P. jullieni.
  A.N. Tan , A. Christianus , S. Shakibazadeh and P. Hajeb
  Local and regional decline of Asian horseshoe crabs has spurred a study on its spawning population at Balok Beach, Kuantan, Pahang, Malaysia. This location was identified as spawning site due to the occurrence of horseshoe crab spawning pairs and nests. Size-frequency, length-weight relationships, sex ratio and epibiont infestation of Tachypleus gigas were studied. Instar stage was estimated based on prosomal width. Condition of the horseshoe crab carapace was reported. Visual search technique of horseshoe crab was conducted during high tide of new and full moons. Prosomal, opisthosomal and telson length and weight of each horseshoe crab were measured. Largest female was recorded with mean prosomal length and width of 154.4 and 246.9 mm, respectively. About 69.8% of the males belonged to size group of 151-200 mm and 53.3% of females were grouped into 201-250 mm. All individuals were of fourteenth to sixteenth instar stages. Sex ratio varied from 0.313 to 2.5 and attributed to commercial harvest and monsoon season. Sand sediment of study site showed 93% of fine sands with grain size ranged from 120 to 250 μm. Acorn and pedunculate barnacle, conical and flat slipper shells were found on the carapace of the specimens. Most males had damaged eyes and carapaces while females with broken telsons. Body damages of about 19.9% on the specimens were likely due to nearby fishing activities. Lack of satellite male indicated low spawning population. The finding of this study showed that the species is extremely threatened by human activities and coastal development.
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