Experimental data on glucose and energy levels of orange mud crab, Scylla olivacea at different water velocities

The present datasets were conducted to investigate glucose concentration in hemolymph, energy levels at selected body parts (hepatopancreas, muscle, gonad), and feces among different sexes of crabs cultured at four different water velocities (0, 20, 40, and 60 cm/s) during a 60-day culture period. A total of 102 immature crabs (51 males, and 51 females) were sampled from Kuala Muda, Kedah coastal water, Peninsular Malaysia (5°39′N 100°19′E) from April to November of 2018. Results indicated that glucose concentration was the highest at water velocity of 60 cm/s for both male and female crabs (♂: 3.76 ± 0.08 mmol/L; ♀: 3.63 ± 0.06 mmol/L), whereas at 0 cm/s, the lowest levels of glucose concentration (♂: 0.13 ± 0.08 mmol/L; ♀: 0.19 ± 0.06 mmol/L) were recorded. As for energy analysis in hepatopancreas, results showed that both male and female crabs recorded the highest levels at 0 cm/s (no flow) with 37.919 ± 0.07 KJ/g and 34.636 ± 0.50 KJ/g, respectively. Energy for locomotion (muscle) of male crabs recorded the highest at 0 cm/s (♂: 26.823 ± 0.06 KJ/g), meanwhile for females, the highest was recorded at 20 cm/s (26.607 ± 0.34 KJ/g). Energy for reproduction of males could not be compared due to an insufficient available amount of testes/vas deferens, whereas female crabs recorded the highest energy usage at 20 cm/s water velocity (♀: 37.895 ± 0.08 KJ/g). For feces, both male and female crabs recorded the lowest energy at 60 cm/s (♂: 5.841 ± 0.03 KJ/g; ♀: 5.393 ± 0.01 KJ/g). Glucose assessment showed a direct relationship between increased velocity and glucose secretion in hemolymph at high velocity of 60 cm/s (stress condition) compared to other treatments. Regarding energy analysis, this research improved the mechanism of hepatopancreas, gonad, muscle and feces functions in development and reproduction, while it shed light on the influence of velocity on energy metabolism of S. olivacea.


a b s t r a c t
The present datasets were conducted to investigate glucose concentration in hemolymph, energy levels at selected body parts (hepatopancreas, muscle, gonad), and feces among different sexes of crabs cultured at four different water velocities (0, 20, 40, and 60 cm/s) during a 60-day culture period. A total of 102 immature crabs (51 males, and 51 females) were sampled from Kuala Muda, Kedah coastal water, Peninsular Malaysia (5 39 0 N 100 19 0 E) from April to November of 2018. Results indicated that glucose concentration was the highest at water velocity of 60 cm/s for both male and female crabs (_: 3.76 ± 0.08 mmol/L; \: 3.63 ± 0.06 mmol/L), whereas at 0 cm/s, the lowest levels of glucose concentration (_: 0.13 ± 0.08 mmol/L; \: 0.19 ± 0.06 mmol/L) were recorded. As for energy analysis in hepatopancreas, results showed that both male and female crabs recorded the highest levels at 0 cm/s (no flow) with 37.919 ± 0.07 KJ/g and 34.636 ± 0.50 KJ/g, respectively. Energy for locomotion (muscle) of male crabs recorded the highest at 0 cm/ s (_: 26.823 ± 0.06 KJ/g), meanwhile for females, the highest was recorded at 20 cm/s (26.607 ± 0.34 KJ/g). Energy for reproduction of males could not be compared due to an insufficient available amount of testes/vas deferens, whereas female crabs recorded the highest energy usage at 20 cm/s water velocity (\: 37.895 ± 0.08 KJ/ g). For feces, both male and female crabs recorded the lowest energy at 60 cm/s (_: 5.841 ± 0.03 KJ/g; \: 5.393 ± 0.01 KJ/g). Glucose assessment showed a direct relationship between increased velocity and glucose secretion in hemolymph at high velocity of 60 cm/s (stress condition) compared to other treatments. Regarding energy analysis, this research improved the mechanism of hepatopancreas, gonad, muscle and feces functions in development and reproduction, while it shed light on the influence of velocity on energy metabolism of S. olivacea.
© Value of the Data Knowledge related to the effect of water velocity on physiological stress can serve as a guideline for the optimal velocity necessary during grow-out phase in captivity [2]. Crab aquaculturist and crab farmers are benefits on this data since it can be used during the fattening activity of the immature crabs. Investigation of crab hemolymph and tissue is crucial to understanding the ecosystem's impact on the general functioning of a crab through velocity tolerance. Experimental data on ecological energy could be further useful to predict several ecological hypotheses, such as constructing relationships between different velocities and offspring or reproductive ability, explaining predator conduct foraging and confirming organism physiological status [3].

Data
Included in this article are the raw data and descriptive data (means) on the effects of water velocities on glucose and energy levels of the orange mud crab, Scylla olivacea. The shared data are recordings from various works including; sampling activities (mud crab), hatchery phase (culturing period for water velocity treatments e Fig. 1), and laboratory work, involving glucose level determination in the hemolymph (Table 1), energy reserves in hepatopancreas (Table 2), energy for locomotion in the muscles (Table 3), energy in the gonad for reproduction (Table 4), and energy usage in the feces (Table 5) of S. olivacea cultured for 60-days. Initial body weight (BW) and carapace width (CW) of each crab was measured and recorded based on previous methods [7e9]. In brief, BW was measured using a digital balance (accuracy: 0.01 g; Shimadzu model, Japan), while CW, using a six-inch liquid crystal display digital Vernier caliper (accuracy: 0.01 cm; Kingsmart brand, Hong Kong) by measuring the distance between the tips of the 9th anterolateral spine of the crab carapace [10,11]. Crabs were then held in an acclimatization tank under ambient light (500 lux) and temperature ± 26 C for 1e2 days before being placed into the PVC pipe prototype. During the acclimatize stage and velocities experiments, the crabs were maintained in 20 ppt water salinity [5]. Cleaning activities included siphoning the feces (feces were collected for energy analysis), excess food sediment, and metabolic waste from the bottom of the tank every morning before introducing new chopped fish [12,13]. During acclimatization, lighting was eliminated    and velocities were set to the required levels as crabs were placed in the PVC pipe setup for 24 h before starting Day 1 of the treatments. The closed system was allowed to run endlessly for 60 days. The water velocity treatments were adapted from Muhammad et al. [2] (Fig. 1). Each crab was maintained and fed with chopped scad fish, Decapterus sp. at 10% of the BW twice daily (0900 and 1700 h) during the 60day cultured period [1,13]. Fifty percent of the water was changed every two days.

Glucose analysis
The hemolymph containing glucose was sampled and extracted (on Day 0, 15, 30, 45, and 60) from the third walking leg by using a sterile syringe with needle (1 cc/ml, TERUMO) [14]. The hemolymph was inserted into 1.5 ml centrifuge tubes and stored in À80 C freezer until further analysis.
Samples were prepared as described in the manual of Glucose kit (Sigma-Aldrich, Inc., USA). Upon extraction, hemolymph samples were thawed and centrifuged at 15,000 rpm, 4 C for 15 minutes. Next, the supernatant was removed and 100 ml of sample was mixed in 400 ml of deionized water, and further vortexed (15,000 rpm, 4 C for 15 minutes). Approximately, 50 ml of hemolymph, and 100 ml of glucose assay reagent was pipetted into plate. The plate was then shaken gently and incubated at room temperature for 30 minutes to ensure uniform color throughout each well. The plate was read at 340 nm using a microplate photometer (Multiskan ™ FC, Thermo Fisher Scientific Inc.). The calculation for glucose levels determination followed Cheng et al. [15], and the final reading was averaged according to respective treatments.

Bomb calorimeter system procedure
The C 2000 calorimeter system is routinely used for determination of gross calorific values of solid and liquid substances. The following processes occur in the measuring cell during an experiment: The dry weight samples used were weighted approximately 1 g each. The samples were then compressed to become pellets using a compressor. Each pellet was then placed on ignition tread. The fuel sample (pellet) then enters the inner decomposition vessel of the measuring cell where pure oxygen flows inside through the oxygen filling apparatus until a pressure of 30 bar has been reached. Meanwhile, water from an external pressure source (water faucet, laboratory thermostat or cooler) flowed into the device and was heated to the working temperature (optionally 25 C/30 C). The inner vessel was filled with temperature-controlled water (at working temperature).
A stirrer ensured there was uniform distribution of heat in the water within the inner vessel as the water temperature of the outer vessel is controlled. The fuel sample (pellet) was then ignited electrically with the ignition wire using a cotton thread. As a result, the increase in temperature of the water in the inner vessel from combustion was measured and the gross calorific value was determined.

Statistical analyses
Differences between male and female glucose and energy levels were analyzed using one-way ANOVA and Tukey HSD test. Arrangement for the possibility of data distribution normality and standardization was assessed using standard normal plot and Cochran's C test. Any significance observed on glucose and energy level within velocities was tested using Kolmogorov-Smirnov test. Data on glucose and energy level was classified into post hoc categories through application of IBM Statistics Version 22 software and Microsoft Excel 2016.