IMPACT OF LOW pH and HIGH TEMPERATURE ON METABOLIC RESPONSE OF MUD CRAB

Tan Jin Mei^1*, Mazlan And. Ghaffar^1,2,3, Hon Jung Liew ^1,2,3,4

¹ Higher Institution Centre of Excellence (HICOE), Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia

² Faculty of Science And Marine Environment, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia

³Institute of Marine Biotechnology, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia

⁴Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Science, Harbin, China

^*Corresponding author: kellytan1504@gmail.com

Climate change derived from ocean warming (OW) and acidification (OA) is known to negatively impact the physiological responses of marine crustacean. However, the impact to intertidal mud crab, Scylla spp. is yet fully understood. Therefore, the objective of the study was planned to determine the interactive impact of temperature and low pH on osmorespiration performance and energy mobilisation of mud crab. Following exposure to temperature (28℃ and 34℃) and pH (ambient: pH 8 and acidic: pH 6.5) for 30 days, all specimens were subjected to osmorespiration assay for oxygen consumption and ammonia excretion rate. Haemolymph of crab was collected for glucose, osmolality, and total haemocyte count (THC). Muscle, gonad and hepatopancreas were collected for total energy contain. The metabolic oxygen consumption and ammonia excretion rates were found to increased concomitantly with temperature, Q₁₀= 2.078 and 1.274 respectively. Negative growth was reported in high temperature indicated metabolic exhausted; however, no significant impact on growth of crab under acidic condition. Higher hepatosomatic index (HSI) was noticed when crabs exposed to high temperature, but, in contrast, lower gonadosomatic index (GSI) were found in crabs exposed to high temperature. Heamolymph osmolality was increased in all high temperatures and low pH condition with low glucose and THC levels. Lipids contain in muscle, hepatopancreas and gonad was decreased significantly in both acidic and high temperature condition indicated high energy expenditure. With all the results remarked that temperature has greater impact on metabolism, growth and energy mobilisation compared to acidic conditions.

Keywords: Climate change, environment, mud crab, metabolic response, pH, physiology, temperature

EFFECTS OF TEMPERATURE ON GROWTH AND PHYSIOLOGICAL RESPONSES OF PATIN BUAH PANGASIUS NASUTUS (BLEEKER, 1863)

Loong Cha Kang^1,*, Sharifah Rahmah^1,2, Abol Munafi Ambok Bolong¹, Hon Jung Liew¹

¹Higher Institution of Centre Excellence (HICOE), Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Malaysia

 ²Faculty of Fisheries and Food Science, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Malaysia

*Corresponding author: loongchakang@gmail.com

Pangasius nasutus also known as Patin Buah locally is among the indigenous freshwater species in Malaysia with high market values and demands. Although, this species is popular, but captive productivity remains inconsistent and most of stock still rely on wild caught that resulted in extreme declining in wild population. Together with climate change scenario, putting this species in critical stage which may threaten their population. Therefore, this study was conducted to study the effect of temperature on growth and physiological responses of P. nasutus. In this study, the experiment was designed with 4 temperature (28 vs. 30 vs. 32 vs. 34°C) and exposed for 37 days followed by osmorespiration assay to assess the cost of living via metabolic oxygen intake and ammonia excretion. During experimentation, feeding and growth performances were monitored every 2 weeks. Results shown that highest total feed intake was recorded for P. nasutus exposed to34°C with 819.93g, followed by 32°C and 30°C at 760.78g and 710.97g respectively, while the 28°C was found with the least total feed intake at 681.51g. Nevertheless, P. nasutus exposed to 34°C showed the least average weight gained with only 46.39g (28.78%), followed 32°C at 81.84g (58.87%), meanwhile P. nasutus exposed to 30°C and 28°C exhibited better growth performance with 113.74g (92.70%), and 138.49g (106.29%), respectively. Similarly, lowest specific growth rate (%/day) was found in 34°C at 0.675%, while the highest in 28°C at 1.948%. Thus, reflected the highest metabolic oxygen intake was found in 34°C with 6.89 μmol/h and the lowest in 28°C at 3.89 μmol/h. These resulted revealed that the growth and physiological responses of P. nasutus is sensitive to environment temperature, the increase of feed intake does not sufficient to fulfilled metabolism needs as growth performance was found to suppress when exposed to high temperature.

Keywords: catfish, climate change, stress, physiology, pangasius

INTERACTIVE IMPACT OF TEMPERATURE LOW pH ON GROWTH AND PHYSIOLOGICAL RESPONSES OF Litopenaeus vannamei

Yu Ling Shirly-Lim¹, Hon Jung Liew¹, Mazlan Abd. Ghaffar^1,2,3

¹Higher Institution of Centre Excellence (HICOE), Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, Kuala Nerus, 21030, Terengganu, Malaysia.

²Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, Kuala Nerus, Malaysia.

³Institute of Marine Biotechnology, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia.

^*Corresponding author: shirlylim@hotmail.com

Environmental changing scenario involves rising of atmosphere temperature leading to unpredictable rainfall volumes with continuous anthropogenic greenhouse gasses releasing have negatively impacted the entire balance ecosystem globally. This impact not only threaten nature population, but also significantly affected cultured animals especially aquaculture animals that rely on water resource. Most of investigation have been focused on wild population, but information about aquaculture species still remains to be investigated. Therefore, this study was designed with two factorial interaction to investigate the interactive impact of high temperature (28°C vs. 34°C) and low pH (pH6 vs. pH8) on growth and physiological responses of Pacific whiteleg shrimp Litopenaeus vannamei. A total of four interactive treatments were designed (i) control (28°C+pH8); (ii) N_temp+L_pH6 (28°C+pH6); (iii) H_temp+N_pH8 (34°C+pH8) and (iv) H_temp+L_pH6 (34°C+pH6) which consisted of 20 shrimps per treatments were subjected to these conditions for 30 days. Results revealed that L. vannamei exposed to H_temp+N_pH8 exhibited lower relative growth rate (RGR) concomitantly with high Specific Growth Rate (SGR). Whereas, L. vannamei exposed to N_temp+L_pH6 showed lowest levels in ammonia excretion rate, weight gain, SGR and RGR with Hepatosomatic index (HPSI). Meanwhile, L. vannamei exposed to H_temp+L_pH6 showed no significant differences in the Body Length (BL), Body Weight (BW), and Hepatosomatic Index (HPSI). Moreover, haemocyte count (THC) also showed no significant differences in the correlation between temperature and pH. However, despite these environmental alterations, the H_temp+N_pH8 performed better and comparable to the control. To diminish the knowledge gaps, it is concluded that adaptations to future environmental conditions must be undertaken within the multifaceted context of aquaculture, with any additional measures or actions to address climate change and the ability to adjust to new environmental conditions. This finding highlighted the need for interactive impact investigation as new core body adaptations to the changing environment to elucidate the physiological growth performances in L. vannamei aquaculture system.

Keywords: Litopenaues vannamei, climate change, physiological responses, growth, environment, shrimp

USE OF BLACK SOLDIER FLY LARVAE MEAL IN HYBRID GROUPER (EPINEPHELUS FUSCOGUTTATUS ♀ × EPINEPHELUS LANCEOLATUS ♂) CULTURE

Enyo Jonathan Ukwela^1,*, Sharifah Rahmah^1,2, Hon Jung Liew^1,3

¹Higher Institution Centre of Excellence (HICOE), Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

²Faculty of Fisheries and Food Science, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

³Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Science, Harbin, China

 *Corresponding author: p4887@pps.umt.edu.my

The unsustainability of fish meal (FM) as a primary source of protein in aquafeed is not a new issue. Researching an alternative functional protein source to replace FM needs urgent attention. With this concern, this study was planned to develop a black soldier fly (Hermetia illucens) larvae (BSFL) diet for hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂) with different percentage of BSFL meal replacement. Four experiment diets comprised of 0, 25, 50, 70% of BSFL meal replacement were formulated to compare with a commercial pellet. After 10 months of feeding trail, feed intake, feed conversion ratio, condition factor, specific growth rate and weight gain were determined. Results revealed feeding and growth performance of hybrid grouper fed with BSFL diets were not significantly different compared to the commercial diets. Feeding and growth performances of grouper fed BSFL diet were comparable with grouper fed commercial diet. This study summarized that BSFL meal is a sustainable alternative meal to substitute FM in hybrid grouper diet.

Keywords: Alternative protein, hybrid grouper, black soldier fly larvae, fish meal, feeding, growth performance.

FOOD SELECTIVITY OF EARLY LIFE STAGE CLIMBING PERCH, Anabas testudineus (BLOCH, 1792)

Mohamad Jalilah*, Suliza Adenan and Hon Jung Liew

Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.

^*Corresponding author: jalilah@umt.edu.my

Giving the correct and sufficient initial food for newly hatched larvae is important to achieve maximum growth performances with well functional early development. The objective of this study was to determine the growth performances of climbing perch A. testudineus larvae fed with different live food (rotifer, moina, artemia and dried bloodworm) as the early food.  Overall, larvae from age 1 to 9-DAH were fed with rotifer only and 10-DAH onwards larvae were fed with 3 combination feeding mode which were (i) rotifer with moina; (ii) rotifer with artemia and (iii) rotifer with bloodworm and (iv) rotifer only for 30 days (30-DAH). The highest survival rate was recorded in the larvae fed with combination moina (T1) at 70% followed by T2 at 57%, T3 at 35% and T4 at 18%. Furthermore, the highest growth performance was noticed in T1 with total length and body weight recorded at 17.78±0.08 mm and 66.8±0.23 g, respectively compared to T4 with lowest length and weight recorded at 8.20±1.86 mm and 27.2±0.10 g. As a remark, combination rotifer and moina is the most suitable food to be used as first exogenous food for Anabas testudineus to achieve higher productivity.

Key words: Anabas testudineus; Larvae; Live feed, Growth rate; Survival rate