Journal of Fisheries and Environment

Mangrove Clam Genus Geloina: A Comprehensive Review of Biology

Ngo Thi Thu Thao, Atupele Ellen Singano — Sun, 01 Dec 2024 00:00:00 +0700

The mangrove clam or mud clam genus Geloina is a vital component of tropical mangrove ecosystems, significantly contributing to their biodiversity. Geloina species display remarkable tolerance, enabling them to thrive across a broad spectrum of salinity levels. They are found in muddy, brackish, and even nearly freshwater regions within mangrove swamps. Mangrove clam Geloina possesses favorable characteristics for marine culture, as they are easy to cultivate. Due to their unique ecological attributes, Geloina clams emerge as objective species for fostering eco-friendly aquaculture. However, environmental factors affecting Geloina species must be considered at all time. The spawning activities of Geloina clams occure almost year around in tropical countries.With broodstock shell lengths of 68.61 and 58.63 mm, the estimated fecundity of Geloina clams ranged from 0.3185×10⁶ to 4.416×10⁶ oocytes. However, larval survival rate is compromised due to many environmental factors. Therefore, the life cycle and growth performance of mangrove clams should be focal points in upcoming studies to explore efficient techniques for seed production and aquaculture practices. This article also addresses these ecological challenges by comprehensively examining the natural science related to Geloina species, focusing on Southeast Asia with Vietnam as a primary focal point. Furthermore, in the strategy towards sustainable resource management, this review also discusses the incorporation of the biological characteristics of Geloina species into extractive aquaculture practices. The information regarding maturation, spawning of broodstock, and specific biological conditions for mangrove clams from this review is valuable for the resource management and aquaculture practices.

The First Records of Pelagic Gastropods Species from the Celebes Sea, North Sulawesi, Indonesia

Sun, 01 Dec 2024 00:00:00 +0700

Despite their weak swimming abilities, which prevent them from swimming against general ocean currents, gastropod larvae can still achieve widespread dispersal. This study aimed to identify pelagic gastropod species, both holoplanktonic and meroplanktonic, and to analyze their distribution in the Celebes Sea. Gastropods were sampled using an Isaacs-Kidd Midwater Trawl (IKMT) during the EWIN 2018 Cruise aboard the R.V. Baruna Jaya VIII LIPI. Species identification relied on morphology and DNA barcoding. Eight holoplanktonic gastropod species were identified: Atlanta inclinata (Atlantidae, Subclass Caenogastropoda), Creseis acicula, Creseis virgula, Boasia chierchiae, Styliola subula (Creseidae), Cavolinia labiata, Telodiacria sp. (Cavoliniidae), and Clio convexa (Cliidae), all belonging to Subclass Heterobranchia. The meroplanktonic species identified, all Caenogastropoda, included Reticutriton pfeifferianus (Cymatiidae), Dulcerana granularis (Bursidae), and Lampasopsis rhodostoma (Bursidae). Most species were found distributed across stations in the eastern and western parts of the Celebes Sea. With the exception of Creseis acicula, Styliola subula, and Reticutriton pfeifferianus, all identified species represent first records for the Celebes Sea. This study marks the first research in the Celebes Sea utilizing morphology and DNA barcoding for identifying pelagic gastropod species, providing a foundational dataset for future investigations.

Effect of Bisphenol A on Expression of Estrogen-, Retinoid- and Thyroid Hormone-Related Genes in the Green Catfish (Mystus nemurus)

Ladda Leelawatwattana, Peasala Sokul, Jiraporn Khwanmunee — Sun, 01 Dec 2024 00:00:00 +0700

The impact of bisphenol A (BPA), a chemical known for its endocrine-disrupting ability, has been investigated in various fish species. This study aimed to examine the effect of BPA on the expression of genes associated with estrogen, retinoid, and thyroid hormones in green catfish (Mystus nemurus). The isolated cDNA fragments, which were 414, 319, 445, and 366 base pairs in length, exhibited significant similarity to brain cytochrome P450 aromatase (cyp19b), transglutaminase-2 (tgase-2), deiodinase type III (dio3), and thyroid hormone receptor alpha (trα), respectively. When translated into amino acids, these cDNA fragments corresponded to approximately 30%, 15%, 55%, and 30% of the full-length length P450AromB, TGase-2, Dio3, and TRα proteins in different fish species, respectively. At 15 days post-hatching, green catfish were exposed to BPA at concentrations of 0.01, 10, 100, and 1,000 nM for three days. The expression of cyp19 decreased compared to the control group when fish were exposed to BPA at 0.01 and 10 nM. The mRNA expression levels of tgase and tr also decreased across all treatment groups compared to the control group. However, no significant changes were observed in the expression of dio across the investigated doses. The study's findings indicate that exposure to BPA at ecologically relevant concentrations leads to changes in gene expression in green catfish.

Length-Weight Relationship, Condition Factor and Otolith Morphometric of Serranus cabrilla from the East Libya Mediterranean Sea Coast

Sun, 01 Dec 2024 00:00:00 +0700

This study investigated the length-weight relationship, condition factor, and otolith morphometrics of Serranus cabrilla specimens captured near the Benghazi coast, Libya, during spring 2021. Total body length (TL), total weight (TW), and otolith dimensions were measured. The mean TL and TW were 15.06±0.12 cm and 41.87±1.13 g, respectively. The regression coefficient (2.72) for the length-weight relationship was not significantly different from 3 according to the t-test (b = 3, p≥0.05), indicating that growth is isometric. Fulton's condition factor (K_f) ranged from 0.77 to 1.81 (mean = 1.20±0.01), and the relative condition factor (K_n) ranged from 0.65 to 1.48 (mean = 1.02±0.01). S. cabrilla otoliths exhibited a fusiform shape with a heterosulcoid sulcus, characterized by a funnel-shaped ostium and a tubular cauda. No significant differences (p≥0.05) were observed between left and right otoliths, so the left otolith was used for subsequent analyses. The otolith length constituted 3.51% of TL, and the height-to-length ratio averaged 42.71±0.39%. Based on relative size (0.36±0.00), the otoliths were classified as medium-sized. Ellipticity, rectangularity, and roundness values were 0.40±0.03, 0.67±0.00, and 0.37±0.00, respectively. The strongest correlation was observed between body length and otolith length.

Photosynthetic Responses of The Red Seaweed Gracilaria fisheri to Green and Brown Seaweed Extracts

Sun, 01 Dec 2024 00:00:00 +0700

Seaweed extracts are widely used as biostimulants in crops for promoting growth and stress resistance. This study examined the photosynthetic responses of Gracilaria fisheri to extracts of green seaweeds Chaetomorpha crassa (Ch-SE) and Rhizoclonium riparium (Rhi-SE), and brown seaweeds Padina sp. (Pad-SE) and Sargassum oligocystum (Sar-SE). Thalli of G. fisheri were treated with varying concentrations of the extracts (0, 1, 2, 3, 4, and 5 g SE×L^-1) under controlled conditions: salinity of 30‰, temperature of 25–26 °C and light intensity of 200 µmol photons×m^-2×s^-1. Photosynthesis was measured using a dissolved oxygen sensor and pulse amplitude-modulated fluorometry. Results showed that light intensity rapidly increased with irradiance up to 625 mmol photon×m^-2×s^-1 without photoinhibition in the SE-treated algae, unlike the control. The electron transport rate (ETR) of the SE-treated algae significantly increased compared to the control at 625 mmol photon×m^-2×s^-1. Net photosynthesis (P_net) of the SE-treated G. fisheri was two- to fivefold higher than the control. Additionally, the maximum quantum yield also increased in SE-treated algae, with the highest increase in Rhi-SE treatment, followed by Pad-SE, Ch-SE, and Sar-SE treatments. This study suggests that green and brown seaweed extracts effectively enhance photosynthesis in G. fisheri.

Impact of Low Salinity on Survival and Growth of Juvenile Mangrove Red Snapper (Lutjanus argentimaculatus Forsskål, 1775) in Indoor Tanks

Sun, 01 Dec 2024 00:00:00 +0700

Mangrove red snapper (Lutjanus argentimaculatus Forsskål, 1775) is a high-value marine fish and an ideal mariculture species. As a euryhaline species, it requires a deeper understanding of optimal cultivation conditions. This study examined the effects of different low salinity levels [20‰, 10‰, and 0‰ (freshwater)] on fish survival (SR) and growth of juvenile red snapper in indoor tanks, with fish reared in seawater (30‰) serving as a control. Fish were fed with commercial marine fish feed (42% protein) for six weeks. Results showed no significant (p≥0.05) differences in survival rates among salinity levels (0–20‰), with survival rates ranging from 95.00–100%, similar to 30‰ (100% SR). The final total length ranged from 9.20–9.55 cm across treatments, with no significant differences. However, fish reared at 20‰ had a significantly higher final body weight (37.43 g) than those at 30‰ (25.06 g), 10‰ (32.42 g), and 0‰ (24.78 g). The highest weight gain rate and specific growth rate were observed in fish at 20‰ (442.50% and 4.02%, respectively), alongside a significantly lower FCR (2.05) than in the 30‰ (2.37), 10‰ (2.17), and 0‰ (2.44) treatments. Based on these findings, a 20‰ salinity level is recommended for nursing juvenile L. argentimaculatus in cultivation systems.

Comparative Effects of Chlorella and Spirulina on Growth, Pigmentation, Breeding, and Stress Tolerance in Guppy (Poecilia reticulata Peters, 1859)

Sun, 01 Dec 2024 00:00:00 +0700

Fish coloration and growth can be enhanced by supplementing Spirulina in feed, though it is relatively expensive. As a cost-effective alternative, Chlorella was used in this study to replace Spirulina. The experiment was conducted by feeding one-day-old guppy (Poecilia reticulata) fry with either a control feed without algal supplementation (C), a diet supplemented with 5% Spirulina (5SP), or a diet supplemented with 5% Chlorella (5CH). After 30 days, the fry fed 5CH had significantly poorer growth performance (p<0.05) compared to 5SP, but not different from the control. Interestingly, there was a trend toward improved final weight and specific growth rate in the 5CH group, though the differences were not statistically significant compared to both 5SP and the control. Similar trends were observed for fry production per female. Additionally, no significant differences were found among treatments in terms of survival (ranged 96–97%), stress tolerance, and most reproductive traits (such as fry size). The colour intensity of fish fed both the 5SP and 5CH diets was significantly enhanced (p<0.05) compared to the control group. In conclusion, supplementing guppy feed with 5% Chlorella can replace Spirulina at the same rate for improving colour intensity, without negative effects on growth, survival, stress, or reproductive performances. However, further studies using higher inclusion levels of Chlorella are recommended, given the slight trend toward improved final weight and fry production in fish fed the Chlorella-supplemented diets.

Organic Acid-Based Natural Deep Eutectic Solvents: A Comparative Study for Chitin Extraction from Crab Shell By-Products

Sun, 01 Dec 2024 00:00:00 +0700

Conventional chitin extraction using acid/alkali method is effective but involves harsh chemicals. Biological methods offer improved consistency but often result in limited chitin solubility. This study evaluated the efficiency of lactic acid-based and succinic acid-based natural deep eutectic solvents (NADES) for chitin extraction from crab shells. Choline chloride was mixed with either lactic acid (lactic-NADES) or succinic acid (succinic-NADES) and combined with crab shell powder (CS) in a 10:1 ratio. The mixture was then heated using microwaves for varying durations. The results showed that lactic-NADES achieved higher demineralization and deproteinization efficiencies than succinic-NADES. Optimal extraction was achieved with 3 M lactic acid at a CS:lactic-NADES ratio of 1:20, with a microwave irradiation time of 5 min, yielding demineralization and deproteinization efficiencies of 97.78±0.73% and 81.33±0.91%, respectively. The microstructure, crystallographic organization, functional groups, and thermal stability of the optimal extracted chitin were then compared to those of conventionally extracted chitin. Analysis using SEM, FT-IR, XRD, and TGA showed that chitin obtained via the lactic-NADES method had characteristics comparable to those extracted using traditional acid/alkali methods. Thus, the lactic-NADES method presents a promising alternative for chitin extraction, offering similar quality with potentially fewer environmental impacts.

The Impact of Bottom Gillnet Construction on Lobster Catch Quality in Segara Bay District, Bengkulu City, Indonesia

Muhammad Natsir Kholis, Novita Mz, Liya Tri Khikmawati — Sun, 01 Dec 2024 00:00:00 +0700

Lobster represents one of the most valuable non-fish species with significant economic potential in Bengkulu City, with the first lobster fishermen's association being established in Segara Bay District. This research aims to identify the construction of bottom gillnets used by fishermen, assess their compliance with the Indonesian National Standards (SNI), and evaluate their impact on lobster catches in the waters of Segara Bay, Bengkulu City. The study was conducted from April to June 2020 using a survey method that directly observed and measured bottom gillnets, fishing activities, and catch characteristics across 42 fishing operations. Results indicated that the identified bottom gillnets did not meet SNI specifications. Consequently, the primary lobster catches, dominated by scalloped spiny lobster (Panulirus homarus), accounted for only 31% of the total catch, while by-catch constituted a significantly high proportion at 69%. Additionally, the catch exhibited uneven size distributions with a high proportion of undersized lobster (62%), and the estimated first catch size (7.8 cm) was smaller than the size at first maturity. These findings highlight the urgent need for comprehensive improvements in the bottom gillnet dimension standards in Indonesia.

Anticancer Activity of Marine Macroalgae Halimeda tuna from Aceh Waters against Cervical Cancer Cells

Sun, 01 Dec 2024 00:00:00 +0700

Cancer, as a chronic illness, is characterized by a high mortality rate. Current cancer treatments, such as chemotherapy, have significant drawbacks, including long half-lives and numerous adverse effects. Medications derived from natural products offer a safer alternative as supplementary treatments. One such natural product is marine macroalgae, commonly known as seaweed. Secondary metabolites from marine macroalgae exhibit a range of potential biological activities, including anticancer properties. The objective of this study was to determine whether the methanolic extract of Halimeda tuna from the Acehnese coast possesses potential anticancer properties. Halimeda tuna was extracted using the cold maceration process, which involved immersion in methanol solvent for 24 h. The MTT assay was used to assess the cytotoxicity of crude H. tuna extract against HeLa cervical cancer cells. GC-MS testing and phytochemical analysis were conducted to identify the compounds present in the extract. The yield of H. tuna extract was 0.168±0.025%. The MTT assay determined the IC₅₀ value of H. tuna against HeLa cells to be 126.460±46.167 µg·mL^-¹. Phytochemical analysis revealed the presence of flavonoids, steroids, and alkaloids, while GC-MS analysis identified fatty acids, steroids, and flavonoids in the extract. These compounds may contribute to the anticancer effects observed, consistent with an IC₅₀ value that indicates moderate cytotoxicity. Further research is required to explore the potential of H. tuna extract as an alternative anticancer agent.

Effects of Density, Morphology, and Photosynthetic Activity in Seaweeds on Nutrient Absorption from Fish Culture Effluent

Boonanan Kaewduang, Nittiya Numuean, Jantana Praiboon, Anong Chirapart — Sun, 01 Dec 2024 00:00:00 +0700

The use of seaweed for nutrient absorption in aquaculture effluent has gained significant attention. This study investigated the effects of density and surface area-to-volume (SA:V) ratios of three seaweeds: Caulerpa lentillifera, Ulva rigida, and Gracilaria fisheri, on nutrient uptake in fish culture effluent. Nutrients absorption of NO₂^-, NO₃^-, NH₄⁺, and PO₄^3- was measured at algal densities of 10, 20, 30, 40, and 50 g·L^-1 every hour over a 24 h period. Optimal absorption of NO₂^-, NO₃^- and PO₄^3- by all three seaweeds occurred at a density of 30 g·L^-1 within 24 h; with maximum removal efficiencies for C. lentillifera reaching 86.03%, 74.08%, and 100%, respectively; for U. rigida, 87.33%, 76.51%, and 100%, and for G. fisheri, 87.82%, 73.77%, and 100%, respectively. At 40 g·L^-1, both C. lentillifera and U. rigida achieved 100% NH₄⁺ removal within 20 h, while G. fisheri showed 100% NH₄⁺ removal within 18 h at a density of 20 g·L^-1. In this study, U. rigida exhibited the highest SA:V ratio (12.99±0.06 cm²:cm³), surpassing that of C. lentillifera (4.48±0.33 cm²:cm³) and G. fisheri (4.07±0.17 cm²:cm³). The SA:V ratio had a positive correlation with total nitrogen reduction, P_net and Fv/Fm. Due to its high SA:V ratio and sheet like morphology, U. rigida was the most effective at nutrient absorption compared to the siphonous-like C. lentillifera and cylindrical, bush-like G. fisheri. These results highlight the influence of photosynthetic response on nutrient absorption with varying algal densities and SA:V ratios, identifying an optimum density of 30 g·L^-1 for green algae and 40 g·L^-1 for red algae.

Effect of Modified Scoop Net Design and Optimal Fishing Time on Catch Weight and Species Composition in the Morosari River Mouth

Gondo Puspito, Sugeng Hartono, Mustaruddin, Ageng Priambada — Sun, 01 Dec 2024 00:00:00 +0700

Scoop nets are widely used in small-scale fisheries, but their efficiency can be limited by timing and design constraints. To address these limitations, the research aimed to determine the best fishing time for using the scoop net and to demonstrate that adding a pocket to the scoop net can increase the catch weight without affecting the species composition. The construction of a standard scoop net is generally similar to that of a lift net. Its main component consists of a piece of net measuring 4×4 m that can be lowered and lifted in the water. The modified scoop net, however, is equipped with a pocket in the center of the net. In the current study, both types of scoop nets were operated simultaneously at locations approximately 20 m apart. The results showed that the best fishing time for the scoop net was between 12:00 p.m. and 04:00 p.m. (GMT +7), yielding 139.66 kg of fish, or 78.87% of the total catch. The modified scoop net caught five species of fish: spot mullet (Moolgarda seheli), barramundi (Lates calcarifer), tiger tooth croaker (Otolithes ruber), spotted scat fish (Scatophagus argus), and long whiskers catfish (Mystus gulio). The standard scoop net caught four of the same species, except for barramundi. The additional pocket reduced the drag force of the modified scoop net to 0.973 kgf, which was 75% of the drag force of the standard scoop net (1.296 kgf). Moreover, the additional pocket of the modified scoop net resulted in a total catch of 147.65 kg of catch, which is 5.02 times the catch weight of the standard scoop net (29.42 kg).

Environmental Drivers of Plankton Backscattering Strength (SV) in Tunda Island's Marine Ecosystem, Banten

Sun, 01 Dec 2024 00:00:00 +0700

Plankton play a crucial role in pelagic ecosystems, serving as a primary food source in marine food webs and influencing nutrient cycling. Hydroacoustic methods are effective for detecting targets such as plankton by generating backscatter values, which indicate their distribution. This approach provides insights into their horizontal and vertical distribution. This research aimed to map and analyze the spatial and temporal distribution of plankton volume backscattering strength (SV) values using hydroacoustic methods, and to examine the relationship between these SV values and environmental parameters in the waters around Tunda Island, Banten. Data collection included oceanographic measurements: temperature, salinity, DO, pH, currents and water clarity, as well as acoustic data. Oceanographic data were gathered from 16 sampling points at the water surface around Tunda Island. The relationship between oceanographic parameters and acoustic data was analyzed using Principal Component Analysis (PCA). The study found that temperatures around Tunda Island ranged from 28 to 30.2 °C, salinity from 30.3 to 33.5‰, pH from 8.1 to 8.4, DO from 6.39 to 7.67 mg·L^-1, water clarity from 9.57 to 34.36%, and currents from 0.13 to 0.69 m·s^-1. The SV for horizontal plankton distribution ranged from -82.04 to -76.06 dB, while vertical distribution ranged from -82.04 to -75.07 dB. PCA analysis showed that the relationship between plankton distribution and aquatic parameters accounted for 57.2% of the cumulative variance, with each parameter making either a positive or negative contribution. This research provides baseline data on plankton abundance and environmental conditions in Tunda Island’s waters, highlighting the use of hydroacoustic methods for detecting fine-scale distribution patterns in relation to ecological variables. The findings contribute valuable insights into plankton ecology in areas impacted by anthropogenic activity, supporting future ecological monitoring, fisheries management, and resource conservation efforts.

Impact of Dietary Nutmeg (Monodora myristica) Seed Extract on Growth Performance, Immune Response, Gut Morphology, Liver Indices, and Hematological Parameters in African Catfish (Clarias gariepinus)

Sun, 01 Dec 2024 00:00:00 +0700

The use of synthetic chemicals as growth promoters and immune boosters in intensive aquaculture has significant negative impacts on the aquatic environment and poses potential risks to human health, necessitating the need for organic alternatives. This study investigated the effects of ethanol extract from Monodora myristica seed (EMM) as a growth promoter, immune booster, and gut area modulator in African catfish (Clarias gariepinus). The crude extract was obtained using a conventional method from finely ground, dried seeds of M. myristica. The extract was incorporated into a 40% crude protein diet at inclusion levels of 0.00% (M0), 0.05% (M1), 0.10% (M2), 0.15% (M3), and 0.20% (M4). These five diets were randomly assigned to triplicate groups of C. gariepinus (2.32±0.03 g), housed in 15 plastic aquaria for 84 days. Results showed that growth performance and feed conversion ratio were improved in the M2 group. Fish fed EMM diets also exhibited increased gut absorption area. Changes in the haematological indices, serum biochemistry, and liver oxidative biomarkers indicated enhanced anti-oxidant and immune responses with EMM inclusion. Specifically, total protein, glutathione peroxidase, glutathione, and glutathione S‐transferase levels significantly increased (p<0.05). Survival rates were higher in M2 and M3 (91.00%) than in the control group (86.67%). This study highlights the positive effects of EMM inclusion at a moderate concentration (0.10%) in the diet of C. gariepinus, particularly on immune response and survival rate.

Effects of Transporting Tapioca Products on Sediment Quality Offshore of Sriracha Bay, Chonburi Province, Thailand

Saranya Rakseree, Prasarn Intacharoen, Vichaya Gunboa, Anukul Buranapratheprat — Sun, 01 Dec 2024 00:00:00 +0700

Transporting tapioca starch in coastal areas leads to dust dispersion, contributing to pollution in Sriracha Bay, Chonburi Province, Thailand. This pollution poses a threat to marine life, highlighting the need for monitoring to prevent environmental harm. To address this issue, sediment samples were collected from 16 locations in Sriracha during both the dry season (March 2020) and the rainy season (August 2020). The study aimed to examine variations in organic matter, a byproduct of tapioca dust transportation, over time. Analysis revealed that silty-clay sediments predominated in the area. During the dry season, sedimentary parameters such as total organic matter (TOM) (8.72±3.21%) and hydrogen sulfide (0.03±0.02 mg Sg^-1), were notably high. In contrast, the rainy season revealed elevated water content, carbon, sulphur (53.59±14.48%, 2.31±0.22 mgg^-1 and 0.16±0.12 mgg^-1, respectively) and higher nutrient levels in pore water, including ammonia, nitrite and total nitrogen (18.12±4.11, 0.14±0.09 and 121.27±31.77 mg NL^-1, respectively). Organic matter in the sediment was particularly concentrated in the northeast region, where tapioca starch was loaded onto ships, coinciding with relatively acidic conditions. These areas showed higher levels of TOM (11.30 –15.91%), especially during the dry season. The study advocates for dust management during tapioca starch transshipment as a crucial measure to mitigate the rise in TOM and hydrogen sulfide, which could jeopardize the marine ecosystem.