Upcycling Approaches of Invasive Suckermouth Catfish as a Control Strategy: Translating Global Practices to Bangladesh

The Suckermouth catfish (Hypostomus plecostomus) is a freshwater species found in Bangladesh that is included in the group of invasive species according to the guidelines of the Ministry of Fisheries and Livestock. The detrimental effects of Suckermouth catfish and possible ways to eradicate them are yet unknown, thus finding substitute foods for fisheries goods is necessary. Before Suckermouth catfish is utilized as a raw material for fish meals, a rigorous analysis of its nutritional value and heavy metal content is required. The results of the analysis of the moisture content, protein content, lipid content, ash content, and carbohydrate content of the muscles showed that the average content percentages were 64.55%, 20.65%, 1.21%, 1.92%, and 11.87%. Additionally, the average concentrations of heavy metals Cu, Zn, Pb, Cd, and Cr in the muscle tissue of Suckermouth catfish were found to be 0.56, 61.76, 0.14, 1.78, and 0.45. Cu, Pb, and Cr levels are below the maximum level of tolerance, in accordance with this study. Conversely, it turned out that the levels of Zn and Cd above the maximum acceptable limits. Of particular, the levels of Cd were found to be around 30-35 times higher compared to the maximum acceptable values, posing a health risk to humans. It is not recommended to utilize this fish as fish meal because its heavy metal concentration exceeds the maximum limit. This heavy metal can build in the body and be harmful if fish meal is made from this species.

Abstract. Hasrianti, Armayani M, Surianti, Putri ARS, Akbar AH. 2022. Analysis of nutritional content and heavy metals of suckermouth catfish (Pterygoplichthys pardalis) in Lake Sidenreng, South Sulawesi, Indonesia. Biodiversitas 23: 3539-3545. Suckermouth catfish (Pterygoplichthys spp.) is one type of freshwater fish that belongs to the category of invasive fish (invasive alien species) in Indonesia based on the regulation of the Indonesian Minister of Marine Affairs and Fisheries Number PER.17/MEN/2009. The presence of suckermouth catfish in Lake Sidenreng with a high population level and increasing over time has resulted in this species dominating the waters. The many impacts caused and the solution has not been found to eradicate the fish, so we need an alternative that can be used to utilize suckermouth catfish, for example, as food to be processed into fishery products. In order to be used as raw material for processed food, a study is needed to determine the nutritional content and heavy metal content in suckermouth catfish. Based on the results of the analysis of the content of crude protein, crude fat and carbohydrate content in the meat of a large (40.3 cm), the content values were 14.52%, 0.49% and 0.21%, while the crude protein, crude fat and fat content were Carbohydrates contained in the meat of suckermouth catfish which are smaller in size (21 cm) are 14.58%, 0.52% and 0.09%. Heavy metals Pb, As, Cd and Hg contained in the meat and scales of suckermouth catfish are also below the metal contamination threshold required based on SNI 2729:2013 so that the fish can be categorized as fish fit for consumption and can be processed into various fishery products with economic value.

A Suckermouth catfish is one type of fish that is considered a pest in the waters because it is invasive (invasive species). In addition to being a pest species, Suckermouth catfish is also known as one type of fish species that has a fairly high heavy metal content in some waters that are classified as polluted waters. This research was conducted with the aim of knowing the content of chemical elements contained in Suckermouth catfish. Based on the results of XRF (X-Ray Fluoroscence) analysis, it shows that there are 14 chemical elements found in the organs of the broom fish, including Sulfur (S), Potassium (K), Calcium (Ca), Phosphorus (F), Silicon (Si). ), Chlorine (Cl), Iron (Fe), Zinc (Zn), Niobium (Nb), Molybdenum (Mo), Antimony (Sb), Ruthenium (Ru), Indium (In), Tin (Sn) and Titanium (Ti ). Meanwhile, based on the results of XRD (X-Ray Diffraction) analysis on the scales of the Suckermouth catfish, the micrograph results obtained in the form of an amorphous which is indicated by the presence of a hump on the graph consisting of 10% Cadmium Mercury, 81% Phosphorus and 9% Calcium, while in the bone Suckermouth catfish consists of 40% Calcium Hydride, 59% Akermanite, and 0.96% Cadmium.

Introduction The effects of flow regimes on the ability of invasive species to establish and maintain populations in the ridge to reef (R2R) systems common to oceanic islands is not well understood. The hydrology of the relatively short, high-gradient, and flashy R2R streams of oceanic islands may be extremely different from that of the continental watersheds invasive species originate from and thus may exert a stronger influence on their ecology. Our objective was to evaluate the effects of annual variability in flow conditions on the growth and recruitment of invasive armored Suckermouth Catfish Hypostomus c.f. watwata in Hawaiian streams. Methods Suckermouth Catfish were captured from three streams of the Ala Wai Watershed on O’ahu. We then measured, weighed, and extracted the lapilli from each fish. We used back-calculated lengths at age to estimate the effects of interannual variability in flow on growth and recruitment. Results Individuals ranged from 0–16 years old and grew rapidly in their first 3 years after which growth slowed substantially. The growth of Suckermouth Catfish was positively influenced by flow conditions indicative of wetter years and more stable flow and negatively influenced by flow conditions indicative of drier years and more variable flows. However, the specific annual flow metrics most strongly influencing growth varied by stream. Similarly, recruitment was positively influenced by higher winter flows with lower daily variability. Discussion The observed effects of flow on Suckermouth Catfish growth and recruitment suggests that they are not particularly well suited for the flow conditions characteristic to R2R systems and that anthropogenic alterations to the hydrology and physical in-stream habitats may have enabled the species to be more successful on O’ahu than it would have been otherwise.

Suckermouth catfish have a unique tail shape with an upturned caudal peduncle and a ventral lobe of the caudal fin that is longer than the dorsal lobe. We visualized the wake flows of four suckermouth catfish (Peterygophichthys gibbiceps) using particle image velocimetry and analyzed the effect of these tail features on their fast-starting behavior. In this study, we measured the jet and ring axis angles of vortex rings generated by suckermouth catfish during a 1.9 body lengths per second (BL s−1) fast start, and recorded their corresponding body, path and tail angles. The results showed that the suckermouth catfish produced an average jet angle of 47.4° despite a mean tail angle of about 20.7° during fast starts. In addition, further studies included evaluating the positional relationship between force and the center of mass of suckermouth catfish and analyzing the balance of forces and moments required by suckermouth catfish during starting in conjunction with the measured fish body density. During fast starts and escapes, the suckermouth catfish can actively control its tail to change the direction of the force and the pitching moment to improve its maneuverability and stability. This study may provide inspiration for the design of new bionic underwater robots and swimming control strategies.

Although a large number of fish species have been introduced into Guangdong Province in Southern China, a few species, such as tilapia (Tilapia spp.), North African catfish Clarias gariepinus Burchell, mrigal carp, Cirrhinus mrigala (Bloch) and the sucker mouth catfish (Hypostomus sp.), have established natural populations and can be considered “successful invaders” in large rivers. The specific mechanisms underlying these contrasting results among different introduced fish species remain understudied. The relationship between multiple abiotic–biotic factors and the success of four invasive species was investigated using survey data for the Guangdong Province river ecosystem. In contrast to previous studies that have considered species‐specific traits, the focus was on economic, ecological and anthropogenic factors to predict invasion success. Four main predictive indicators were found: (1) successful invaders were of low or no commercial value; (2) successful invaders tolerated a wide range of environmental conditions, including poor water quality; (3) biodiversity loss accelerated the growth of non‐native populations; (4) human disturbance facilitated population growth and spread of invasive fish species. To lessen the impacts of invasive fish species, the selection of breeding species and breeding areas, maintenance of water quality and reduction in water pollution, protection of the diversity of fish species and reduction of human interference should be addressed.

Invasive alien species (IAS) influence the trophic organisation and food web structure in an invaded ecosystem, and therefore, it is imperative to quantify the resultant ecological impacts. The globally recognised ecosystem modelling platform, Ecopath with Ecosim, was used to delineate the impacts of IAS on a tropical freshwater pond ecosystem in India. We analysed the trophic interactions, consumption patterns, prey overlap and mixed trophic impacts of three co-existing invasive alien fish species, African catfish (Clarias gariepinus), suckermouth catfish (Pterygoplichthys pardalis) and Mozambique tilapia (Oreochromis mossambicus), on other functional groups in the ecosystem. Together, the three IAS shared 11% of the total energy consumption and about 50% of the energy consumption by the fish species/groups. There was no predation mortality for African catfish and suckermouth catfish, and a very low estimate for the same was recorded for tilapia (0.64year-1). The IAS shared high mean prey overlap with the native fish groups (Garra sp., Etroplus suratensis, Systomus sarana, Chanda nama and various small species of the cypriniform genera Puntius, Rasbora and Devario) indicating a substantial competition between alien and native species in the ecosystem. Consequently, the three IAS exhibited higher mean negative mixed trophic impacts on these functional groups. A very high Finn's cycling index (39.59%), a low relative ascendency (28.5%) and a very low system robustness (0.07) were observed compared to similar ecosystems, and the baseline values. These indices exposed the vulnerability of the ecosystem towards perturbations, which could be due to the presence of multiple alien invasive species. Mitigating the impacts of IAS should involve a combination of approaches, including eradication through draining and harvesting, high-density stocking of similar trophic level fish in the pond, and local and national level policy interventions.

Purpose. Assessment of the dynamics of heavy metal accumulation in water, bottom sediments, and fish of water bodies of different purposes in Dnipropetrovsk region. Methodology. The study on heavy metal contents in water, bottom sediments, and hydrobionts (fish) was conducted at various water bodies (Dnipro-Donbas hydraulic canal), fish ponds (ponds of PrJSC “AgroSoyuz”, PrJSC “Petrykivsky Rybhosp” and PE «Agrofirma «Nakhodka»), and multipurpose reservoirs (Dnipro reservoir, Sholokhivske reservoir) in Dnipropetrovsk region from 2015 to 2024. The determination of heavy metal concentrations (Pb, Cd, Mn, Cu, Fe, Ni, Zn) was carried out at the laboratory of the Research Center for Biosafety and Environmental Monitoring of Agricultural Resources of Dnipro State Agricultural and Economic University. The metal content was analyzed using atomic absorption spectrophotometry. The heavy metal contents were measured in four fish species (European perch, roach, Prussian carp, common carp). Sampling, data processing, and statistical analysis were conducted according to standard hydrochemical, hydrobiological, and ichthyological methods. The heavy metal contents were determined in fish muscles. Water quality was assessed according to general requirements and standards for fishery water bodies. Findings. The heavy metal contents in ecosystems of water bodies of different purposes was determined. In the sediment of ponds of PrJSC “AgroSoyuz” and PrJSC “Petrykivsky Rybhosp”, the heavy metal contents were significantly higher than in water or fish body: manganese within 41.24–68.43 mg/kg, cadmium – 0.32 mg/kg, lead 1.50–4.90 mg/kg (for ponds of PrJSC “AgroSoyuz”); manganese – 29.73 mg/kg, cadmium – 0.54 mg/kg, lead 5.72 mg/kg (for recreational pond of PrJSC “Petrykivsky Rybhosp”). For the water of these ponds, which is used for aquaculture, an excess of the content of some heavy metals – Mn, Zn, Cd - was recorded, and for the pond of PrJSC “AgroSoyuz” also Cu. Exceeding the normative heavy metal content for pond water of PE “Agrofirma “Nakhodka” was not noted. The content of some heavy metals in the water of the upper part of the Dnipro reservoir (Cu, Fe) did not meet the fishery norms. At the same time, the heavy metal contents in water and fish of these water bodies does not exceed the fishery standards for water used for fishery purposes. The heavy metal contents in the water of the upper part of the Dniprovske Reservoir (except for the Samara Bay) corresponded to fishery standards. The water in the Dnipro-Donbas hydrotechnical canal was characterized by high levels of heavy metals. Of the 6 investigated heavy metals, the maximum allowable concentrations were not exceeded only for lead (0.40 mg/dm3) The heavy metal contents in C. carpio muscles (juveniles and table fish) in different ponds of PrJSC “Petrykivskyi Rybhosp” (nursery and fattening) corresponded to fishery standards during the three years of the study (2011, 2015, 2016). In the Sholokhivske reservoir, the zinc content in C. gibelio muscles was 46.50 mg/kg, slightly exceeding the maximum allowable concentrations. Exceedances of copper and lead content were not noted. For fish from the Dnipro reservoir, the content of most heavy metals was elevated. In the meat of pelagic roach (R. rutilus), only copper content was within the normal limits (1.56 mg/kg), while all other 6 heavy metals exceeded the maximum allowable concentrations. In the meat of benthophagous Prussian carp (C. gibelio), elevated levels of accumulation of heavy metals were observed for manganese, iron, lead, and nickel, while zinc, copper, and cadmium content were within the standards. In the meat of European perch (P. fluviatilis), the highest content of heavy metals was observed for iron (80.54 mg/kg), with elevated levels observed for manganese, zinc, lead, and nickel. The obtained results indicate that the hydroecosystem of the Dniprovske reservoir, unlike other water bodies in the region, is significantly polluted with heavy metals. This is adequately reflected in the levels of heavy metal accumulation in the organisms of fish from different ecological groups - pelagic herbivores, benthophagous bottom-feeders, and predators. Originality. For the first time, the content of heavy metal accumulation in water, bottom sediments, and fish of water bodies of different purposes in Dnipropetrovsk region has been carried out over several years (2015–2024). Practical Value. The obtained results have theoretical and practical importance for the preparation of scientific-biological justifications for the fishery use of water bodies of various purposes in the region. Continuous monitoring of the heavy metal contents in hydrobionts is necessary to ensure food safety and the quality of raw materials and food fish products. Keywords: Dnipropetrovsk region, heavy metals, Dnipro Reservoir, Dnipro-Donbas Canal, ponds, Sholokhivske Reservoir, water, sediment, fish, accumulation of pollutants.

The Rapid Assessment of Invasive Alien Species in Wetlands of Lao PDR, was conducted to assess the status of four key invasive alien species such as Giant mimosa (Mimosa pigra), Water hyacinth (Eichhornia crassipes), Golden apple snail (Pomacea canaliculata), Suckermouth catfish (Hypostomus plecostomus) at three wetland sites, including Beung Kiat Ngong in Champasack Province, Xe Champhone in Savannakhet Province and Nong Nga Swamp in Borlikhamxay Province. The study included field surveys and interviews of key informants from communities. The study showed that all invasive species are commonly found in wetlands, streams, riverbanks, ponds and rice fields. Local people opinion on floods brought and distributed IAS over these areas. Only Suckermounth catfish is not significant in all three study sites. Mimosa pigra is the most concerned from people’s opinion. It is fast growing and difficult to manage, having no benefits to human and environment. Water hyacinth impacts on water flow, creating thicker sludges along wetland edges, riverbanks and oxbow swamps. Water hyacinth is of highest concerns in Xe Champhone wetlands. People are having difficulties in fishing and boat travelling where the giant mimosa and water hyacinth are invading. When Golden apple snail is present, the variety of aquatic resources is getting loss, such as smalls fishes, shrimps, native snails. Golden apple snails also ate rice plants. However, some families, collect apple snails for sell as an extra income. No special management plan from local government or development projects for invasive species eradication. Some attempts can be done by communities to manage IAS such as cutting, ploughing, and burning mimosa. People collected water hyacinth by hand, left on the ground to dry and burn. For apple snails, farmers collected from their own fields let them dry on the ground. A collaboration on IAS eradication environmentally is required, financial supports from government and international organization is needed.

The introduction of invasive suckermouth catfish (SMC) Hypostomus plecostomus has greatly affected the freshwater ecosystems in Bangladesh, posing a significant threat to indigenous fish species. This species is not commonly harvested and consumed, sparking debate over whether to eradicate it from the natural waterbody or repurpose it beneficially. This study explored the feasibility of utilizing SMC as a partial or complete replacement of commercial fish meal (CFM) in the diets of climbing perch Anabas testudineus, assessing impacts on growth performance, whole‐body composition, hematobiochemical parameters, intestinal and liver health, and economic viability. Five isoproteic (32% crude protein) and isocaloric (9% crude lipid) diets were formulated with varying SMC levels: (0% [D1, control], 25% [D2], 50% [D3], 75% [D4], and 100% [D5]) and fed to fish until satiety over 90 days. Diets D1–D3 significantly improved palatability, growth metrics (final weight, weight gain, and specific growth rate), and feed utilization (feed conversion ratio and protein efficiency; p < 0.05), compared to D4 and D5. Enhanced levels of white blood cells, lymphocytes, and platelets were also recorded in D1–D3 (p < 0.05). Blood biochemical parameters varied significantly across treatments (p < 0.05), but no specific trend was observed. Superior intestinal integrity characterized by abundant goblet cells, intact stratum compactum, and well‐developed villi was observed in D1–D3, along with improved liver morphology, particularly in D3. Economically, D1–D3 treatments yielded better outcomes, including higher production, reduced feed cost, increased revenue, gross margin, return on investment (ROI), and profit index (PI). Overall, replacing CFM with SMC up to 50% proved effective, supporting optimal growth, health, and profitability in A. testudineus, while offering a sustainable strategy to mitigate the ecological impact of this invasive species.

Effective management strategies are needed to control expansion of invasive alien plant species and attenuate economic and ecological impacts. While previous theoretical studies have assessed optimal control strategies that balance economic costs and ecological benefits, less attention has been paid to the ways in which the spatial characteristics of individual patches may mediate the effectiveness of management strategies. We developed a spatially explicit cellular automaton model for invasive species spread, and compared the effectiveness of seven control strategies. These control strategies used different criteria to prioritize the removal of invasive species patches from the landscape. The different criteria were related to patch size, patch geometry, and patch position within the landscape. Effectiveness of strategies was assessed for both seed dispersing and clonally expanding plant species. We found that, for seed‐dispersing species, removal of small patches and removal of patches that are isolated within the landscape comprised relatively effective control strategies. For clonally expanding species, removal of patches based on their degree of isolation and their geometrical properties comprised relatively effective control strategies. Subsequently, we parameterized the model to mimic the observed spatial distribution of the invasive species Antigonon leptopus on St. Eustatius (northern Caribbean). This species expands clonally and also disperses via seeds, and model simulations showed that removal strategies focusing on smaller patches that are more isolated in the landscape would be most effective and could increase the effectiveness of a 10‐yr control strategy by 30–90%, as compared to random removal of patches. Our study emphasizes the potential for invasive plant species management to utilize recent advances in remote sensing, which enable mapping of invasive species at the high spatial resolution needed to quantify patch geometries. The presented results highlight how this spatial information can be used in the design of more effective invasive species control strategies.

An experiment to determine the chemical composition and protein quality of 13 fish substrates (pollock by-products, n = 5; fish protein hydrolysates, n = 5; and fish meals, n = 3) was conducted. Two of these substrates, salmon protein hydrolysate (SPH) and salmon meal with crushed bones (SMB), were used to determine their palatability as components of dog diets. Pollock by-products differed in concentrations of CP, crude fat, and total AA by 71, 79, and 71%, respectively, and GE by 4.1 kcal/g. Fish protein hydrolysates and fish meals were less variable (approximately 18, 14, and 17%, and 1.4 kcal/g, respectively). Biogenic amine concentrations were much higher in fish protein hydrolysates as compared with pollock by-products and fish meals. Pollock liver and viscera had the highest total fatty acid concentrations; however, red salmon hydrolysate and SMB had the highest total PUFA concentrations (49.63 and 48.60 mg/g, respectively). Salmon protein hydrolysate had the highest protein solubility in 0.2% KOH. Based on calculations using immobilized digestive enzyme assay values, lysine digestibility of fish meal substrates was comparable to in vivo cecectomized rooster assay values and averaged approximately 90.3%. Also, pollock milt, pollock viscera, red salmon hydrolysate, and sole hydrolysate had comparable values as assessed by immobilized digestive enzyme assay and rooster assays. A chick protein efficiency ratio (PER) assay compared SMB and SPH to a whole egg meal control and showed that SMB had high protein quality (PER = 3.5), whereas SPH had poor protein quality (PER value less than 1.5). However, using whole egg meal as the reference protein, both fish substrates were found to be good protein sources with an essential AA index of 1.0 and 0.9 for SMB and SPH, respectively. In the dog palatability experiments, a chicken-based control diet and 2 diets containing 10% of either SPH or SMB were tested. Dogs consumed more of the SPH diet compared with the control, and similar amounts of the SMB and control diets. The intake ratios for each were 0.73 and 0.52, respectively. Salmon protein hydrolysate was especially palatable to dogs. These data suggest that chemical composition and nutritional quality of fish substrates differ greatly and are affected by the specific part of the fish used to prepare fish meals and fish protein hydrolysates.

Accurate analysis of present distributions and effective modeling of future distributions of invasive alien species (IAS) are both highly dependent on the availability and accessibility of occurrence data and natural history information about the species. Invasive alien species monitoring and detection networks (such as the Invasive Plant Atlas of New England and the Invasive Plant Atlas of the MidSouth) generate occurrence data at local and regional levels within the United States, which are shared through the US National Institute of Invasive Species Science. The Inter-American Biodiversity Information Network's Invasives Information Network (I3N), facilitates cooperation on sharing invasive species occurrence data throughout the Western Hemisphere. The I3N and other national and regional networks expose their data globally via the Global Invasive Species Information Network (GISIN). International and interdisciplinary cooperation on data sharing strengthens cooperation on strategies and responses to invasions. However, limitations to effective collaboration among invasive species networks leading to successful early detection and rapid response to invasive species include: lack of interoperability; data accessibility; funding; and technical expertise. This paper proposes various solutions to these obstacles at different geographic levels and briefly describes success stories from the invasive species information networks mentioned above. Using biological informatics to facilitate global information sharing is especially critical in invasive species science, as research has shown that one of the best indicators of the invasiveness of a species is whether it has been invasive elsewhere. Data must also be shared across disciplines because natural history information (e.g. diet, predators, habitat requirements, etc.) about a species in its native range is vital for effective prevention, detection, and rapid response to an invasion. Finally, it has been our experience that sharing information, including invasive species dispersal mechanisms and rates, impacts, and prevention and control strategies, enables resource managers and decision-makers to mount a more effective response to biological invasions

Suckermouth catfish (Pterygoplichthys pardalis) is a type of foreign fish (South America) which is prohibited from entering Indonesia because it can endanger ecosystems and the aquatic environment by its invasive nature. The existence of janitor fish threatens the sustainability of the endemic fish of Tempe Lake in Wajo Regency. Until now, there has been no study regarding the quality and food safety for the use of suckermouth catfish in the regency. This study aims to analyzed the heavy metal content of lead (Pb), mercury (Hg) and arsenic (As) of janitor fish in Wajo Regency. Samples of janitor fish were taken from three districts in Wajo Regency used a purpossive sampling technique. Analysis of Pb, Hg and As metals on meat, scales/skin, and bones/fins of suckermouth catfish, refers to SNI 2354.5: 2011, SNI 2354.6-2016 and SNI 01-4866-1998. The results show that suckermouth catfish from the three districts are not contains Pb but contains Hg and As which do not exceed the requirements for metal contamination content limits based on SNI 2729: 2013 concerning requirements for quality and safety of fresh fish

Echinococcosis remains a major public health concern in Xizang, China, where comprehensive control measures have been implemented for many years. Evaluating the cost-effectiveness of key interventions, including population screening, patient treatment, and dog deworming, is essential for optimizing control strategies and improving health resource allocation. Annual data on the three major echinococcosis prevention and control measures implemented in 74 counties of Xizang between 2015 and 2022 were collected. The costs of population screening, patient treatment, and dog deworming were estimated. By comparing the actual disability-adjusted life years (DALYs) of echinococcosis in each county with the estimated DALYs under a no-intervention scenario, the DALYs averted by the prevention and control measures were quantified. Cost-effectiveness analysis was conducted using the incremental cost-effectiveness ratio (ICER) and the ICER-to-GDP ratio. From 2015 to 2022, the total investment in the three major prevention and control measures for echinococcosis in Xizang amounted to 14,519.41 10k CNY. During this period, the interventions cumulatively averted 12,531.9 DALYs. The average ICER was 1.16 10k CNY per DALY averted, corresponding to an ICER-to-GDP ratio of 0.20. Overall, the implemented interventions demonstrated favorable cost-effectiveness and health benefits in most regions, although substantial disparities were observed across different areas. Notably, eight counties had an ICER exceeding 6.00 10k CNY/DALY, and ten counties had an ICER-to-GDP ratio greater than 1. The comprehensive echinococcosis prevention and control measures in Xizang have significantly reduced the disease burden and demonstrated overall favorable cost-effectiveness. However, cost-effectiveness varied considerably across regions. Strategies should be dynamically adjusted based on local epidemiological characteristics, with targeted interventions implemented to optimize health resource allocation and improve prevention and control efficiency.