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INTRODUCTIONSandfish, Holothuria scabra, is among the most commercially important species of tropical sea cucumbers, with premium grade dried H. scabra sold for as much as US$1,670 kg−1 in SE Asian seafood markets (Purcell, 2014). High market value and increase in demand have driven the exploitation of this species to a point where there is severe depletion of wild populations (Anderson et al., 2011; Purcell et al., 2014). Development of culture technology for H. scabra to enhance fishery production and to rebuild natural stocks through the release of hatchery‐produced juveniles has been achieved in several countries with varying levels of success (Battaglene et al., 1999; Ramofafia et al., 2003; Juinio‐Meñez et al., 2013; Juinio‐Meñez et al., 2014; Bowman, 2012; Taylor et al., 2016; Hair et al., 2016). In the Philippines, large scale production of sandfish juveniles (≥3 g) is carried out using floating hapa nets (Juinio‐Meñez et al., 2012), consisting of a fine (1 mm) mesh net suspended in the ocean from a rigid frame. Post‐settled sandfish juveniles are generally grazers and feed primarily on periphytic assemblages that develop on the inside surfaces of the hapa nets. These periphyton assemblages served as primary food source for sandfish juveniles throughout the 30–60‐day ocean nursery culture period (Gorospe et al., 2020, 2021; Sinsona & Juinio‐Meñez, 2019; Altamirano et al., 2021).During the ocean nursery culture period, hapa nets also attract the recruitment of several species of opisthobranchs, crustaceans and fishes possibly due to high food availability and refugia provided by the net enclosures. Although recruitment and impact of the opisthobranch Stylocheilus striatus within hapa nets used for the culture of sandfish juveniles have been previously reported (Gorospe et al., 2021), the diversity of animals recruiting into hapa nets during sandfish juvenile culture is unknown, and without this knowledge, the potential impacts of predators and competitors on sandfish juveniles during this vital culture period have not previously been considered. This study was conducted as a census of potential predators and competitors of sandfish juveniles during floating hapa ocean nursery culture at two sites in the Philippines. Additionally, the influence of potential predators and competitors on growth and survival of sandfish juveniles was assessed. An understanding of the presence of potential predators and competitors and their impacts during nursery culture of sandfish is fundamental to developing predation and interspecific competition mitigation measures as basis for optimizing production of sandfish juveniles during floating hapa nursery culture. In addition, results of this study will provide guidelines relating to the selection of appropriate culture sites for hapa‐based ocean nursery culture of sandfish juveniles.MATERIALS AND METHODSSite descriptionPotential predators and competitors of sandfish juveniles reared in floating hapas were identified and enumerated for a period of up to 69 days at two established sandfish culture sites in the Philippines. The first study site was in Bolinao, northwestern Pangasinan (16.38450833°N, 119.96945278°E), with water depth of 5 m and a bottom substrate of muddy sand covered sparsely with the seagrass, Enhalus acoroides. The second study site was at Maliwaliw, eastern Samar (11.10513°N, 125.58088°E), and adjacent to a mangrove area with a bottom substrate of muddy sand with sparse coral rubble, and a water depth of 2–3 m at low tide.Sandfish juvenile productionSandfish juveniles used at the Bolinao and Maliwaliw sites were produced at the Bolinao Marine Laboratory of the University of the Philippines‐Marine Science Institute and at the Guiuan Marine Fisheries Development Center of the Bureau of Fisheries and Aquatic Resources, respectively.Experimental designIndividual hapa net modules (mesh: 1 mm; 2 × 1 × 1.2 m3) were constructed and deployed following the methods of Sinsona and Juinio‐Meñez (2019) and Altamirano et al. (2021) (Figure 1). Potential predators and competitors were monitored within each hapa net deployed at Bolinao (n = 5) and at Maliwaliw (n = 5), Philippines. Each hapa net was stocked with 1000 sandfish juveniles with average initial length of 4.4 ± 0.01 mm (Bolinao) and 5.7 ± 0.6 mm (Maliwaliw). Juvenile culture methods varied at the two sites. At Maliwaliw, where the seawater was relatively pristine, the hapa nets were deployed 4 days prior to the start of the experiment to ensure the establishment of periphyton, which served as food for the post‐settled juveniles within the hapa nets. Establishment of periphyton within the hapa nets was relatively faster at the Bolinao site because of nutrient enrichment from intensive mariculture activity in the area; thus, the hapa nets were deployed on the same day the post‐settled sandfish juveniles were released to avoid clogging the nets. All potential predators and competitors that were found inside the hapa nets were removed prior to the release of juveniles. At Bolinao, hapa nets were changed on days 23 and 46, whereas hapa nets were changed once at Maliwaliw on day 30. The change nets were done to ensure high density of periphyton within the hapa nets. Additionally, sandfish juveniles reared in Bolinao were sorted and reared according to size classes and the stocking density of sandfish juveniles reduced to facilitate faster growth, following established culture protocols (Sinsona & Juinio‐Meñez, 2019; Altamirano et al., 2021). Conversely, sandfish juveniles reared at Maliwaliw were not sorted by size, and all surviving juveniles were transferred to their respective new hapa nets following growth and survival monitoring on day 30. This study was conducted between March and July 2022, and the census was ceased at both sites after 69 days. Sea surface temperature was recorded at 30.4 ± 0.3 and 30.3 ± 0.3°C at Bolinao and Maliwaliw, respectively. Additionally, average salinity at Bolinao was 33.6 ± 0.2 and 33.0 ± 0.3 ppt at Maliwaliw throughout the duration of the study.1FIGURE(A) Doublet (two hapa nets in a single module) and (B) singlet (one hapa net per module) floating hapa ocean nursery system used in this study at Bolinao and Maliwaliw sites, respectively.Growth and survival of sandfish juvenilesGrowth and survival of sandfish juveniles reared in floating hapa nets in Bolinao were determined on days 23, 46 and 67, and in Maliwaliw on days 20, 30, 45 and 62, each from five replicate hapa nets at each site. Thirty sandfish juveniles from all hapas at each site were photographed with a scale reference. Total body lengths of each juvenile were measured digitally using Coral Point Count 4.1 (CPCe) software (Kohler & Gill, 2006). Growth performance of sandfish juveniles was computed as mean length (mm) and absolute growth rates (AGRs, mm day−1). AGR (mm day−1) was calculated as the difference between final and initial mean length of the sandfish juveniles over the monitoring period. Survival was estimated by counting all the juveniles remaining in each hapa net on each monitoring day and was expressed as the percentage of the juveniles surviving from the initial stocking density and thereafter, from the density recorded during the previous monitoring period.Potential predators and competitorsPotential predators and competitors found inside each hapa net on each monitoring day were identified, counted, measured and discarded. An animal was considered a competitor if exhibiting a similar feeding habit or diet to sandfish juveniles, and/or likely to compete for living space. Potential predators are those exhibiting carnivorous feeding mechanisms. The frequency of each potential predator or competitor was expressed as the percentage of the total number of potential predators and competitors in each hapa net.Data analysisDifferences in mean length, AGRs and survival of sandfish juveniles between Maliwaliw and Bolinao on different comparable monitoring days except day 30 (i.e. Maliwaliw) were tested using Student's t‐test. Differences were considered statistically significant at p < 0.05. To gain further insight on the influence of predation and competition on sandfish juveniles, the correlation between the number of potential predators/competitors and survival and between the number of predators/competitors and AGR of sandfish juveniles was determined using Pearson's r correlation.RESULTSPotential predators and competitorsThe lists of potential predators/competitors of sandfish juveniles found inside floating hapa nets in Bolinao and Maliwaliw across the different comparable monitoring periods are shown in Tables 1a and b, respectively. There were 26 identified species belonging to different families of fishes (Bleniidae, 2 species; Terapontidae, 1 species; Clupeidae, 1 species; Siganidae, 3 species; Lutjanidae, 1 species; Atherinidae, 1 species; Monacanthidae, 1 species; Engraulidae, 1 species), molluscs (Strombidae, 1 species; Ostreidae, 1 species; Aplysiidae, 4 species, and 1 unidentified species of crab (probably leucosiid), crustaceans (Sergestidae, 1 species; Penaeidae, 1,2 species, Portunidae, 2 species; Grapsidae, 1 species; Sphaeromatidae, 1 species) and polychaete worms (Polychaeta, 1 species) at both sites at different monitoring periods.1aTABLETaxonomic group and feeding habit of potential predators and competitors of sandfish Holothuria scabra juveniles recorded within floating hapa ocean‐based nursery system reared at Bolinao, Northwestern, Philippines across comparable monitoring periods (b). Taxonomic group and feeding habit of potential predators and competitors of sandfish Holothuria scabra juveniles recorded within floating hapa ocean‐based nursery system reared at Maliwaliw, Eastern Samar, Philippines across comparable monitoring periodsDay 23Day 46Day 69GroupFamilyScientific nameFeeding habitMean length (mm)% CompMean length (mm)% CompMean length (mm)% CompFishBlenniidaePetroscirtes mitratusDetritivore; feeds bottom detritus and algae (Sano et al., 1984)352.2TerapontidaePelates quadrilineatusCarnivore; feed on small fishes and invertebrates (Adhiambo, 2009)24.30.4230.6SphaeromatidaeCymodoce sp.Detritivore; feeds on decaying plant and animal matter (Arrontes, 1990)80.4938.5ClupeidaeAnodontostoma chacundaOmnivore, feeds on microalgae, protozoans and crustaceans (Whitehead, 1985)2050.6SiganidaeSiganus canaliculatusHerbivore; feed on benthic algae and to some extent on seagrass (Woodland, 1997)1350.6AtherinidaeAtherinomorus lacunosusCarnivore; feeds on planktonic crustaceans (Hobbs & Chess, 1973)626.7MolluscsStrombidaeCanarium labiatumDetritivore; feeds on detritus (personal observation)1822.6121.22810AplysiidaeStylocheilus striatusHerbivore; feeds on cyanobacteria and periphytic assemblage (Paul & Pennings, 1991; Gorospe et al., 2020)3659.93150.95073.3Stylocheilus longicaudaHerbivore, feeds on cyanobacteria and periphytic assemblage (Paul & Pennings, 1991)311.1511.9Dolabella auriculariaHerbivore; feed on variety of seaweeds (Pennings et al., 1993)156.6Bursatella leachiiHerbivore; feeds on a variety of seaweeds and cyanobacteria (Masterson, 2008)545.8OstreidaeCrassostrea sp.Omnivore; feeds on suspended microalgae and non‐algal matter such as copepods and rotifers (Hawkins et al., 1998)171.4CrustaceansPortunidaeThalamita sp.Carnivorous; feed on wide variety of bottom dwelling invertebrates (Cannicci et al., 1996)80.4181.2136.7LeucosiidaeUnidentified leucosiid–50.4PenaeidaePenaeus sp.Omnivore; feeds on small crustaceans, polychaetes and detritus materials (Marte, 1980)340.36Segmented wormPolychaetePolychaeteOmnivore; surface and subsurface deposit feeders, suspension (or filter) feeder (Checon et al., 2017)283.31bTABLE. Taxonomic group and feeding habit of potential predators and competitors of sandfish Holothuria scabra juveniles recorded within floating hapa ocean‐based nursery system reared at Maliwaliw, Eastern Samar, Philippines across comparable monitoring periodsDay 20Day 30Day 45Day 62GroupFamilyScientific nameFeeding habitMean length (mm)% CompMean length (mm)% CompMean length (mm)% CompMean length (mm)% CompFishLutjanidaeLutjanus sp.Carnivore; feeds on wide array of diet, including other fishes, crustaceans, gastropods and polychaetes (Kamukuru & Mgaya, 2004)210.2SiganidaeSiganus fuscescensHerbivores; feed on algae and seagrasses (Woodland, 1990)480.8Sceloporus virgatusHerbivores; feed on benthic seaweeds (Woodland, 1997)500.8EngraulidaeStolephorus indicusOmnivore; feeds most likely on zooplankton and phytoplankton (Hajisame et al., 2004)174.1MonacanthidaeParamonacanthus japonicusFeeds on algae (Hutchins, 1997)100.8BlenniidaeUnidentified fish (Blenidae)290.4MolluscsStrombidaeCanarium LabiatumDetritivore; feeds on detritus130.4AplysiidaeBursatella LeachiiDetritivore; feeds on a variety of diatoms, plant and animal debris (Paige, 1988)450.2Stylocheilus striatusHerbivore, feeds on cyanobacteria and periphytic assemblage (Gorospe et al., 2021)390.4OstreidaeCrassostrea sp.Omnivore; feeds on microalgae and non‐algal matter such as copepods and rotifers (Hawkins et al., 1998)131.4UNIDGastropod unidentified80.6CrustaceansGrapsidaeGrapsus albolineatusOmnivore; feeds on filamentous algae and occasionally animal matter (Kennish et al., 1996)223.2PortunidaeThalamita sp.Omnivore, cannibalistic scavenger; feeds on bivalves, slow moving crustaceans and other invertebrates (Cannicci et al., 1996)140.2161.6173.3PenaeidaePenaeus sp.Omnivore; feeds on small crustaceans, polychaetes and detritus materials (Marte, 1980)5416.7466.14417.9SergestidaeAcetes sp.Omnivore; feeds phytoplankton, zooplankton and detritus (Metillo et al., 2015)2333.32331.7IsopodSphaeromatidaeCymodoce sp.Detritivore; feeds on decaying plant and animal matter (Arrontes, 1990)983.31056.7995.21140.7The highest number of potential predators/competitors that recruited within the floating hapas was observed on day 23 in Bolinao and this decreased over time. Potential predators and competitors in floating hapas in Bolinao were dominated by the opisthobranch S. striatus which made up 59.9%, 50.9% and 73.3% of recorded taxa on days 23, 45 and 69, respectively (Table 1a; Figure 2). This was followed by the Samar conch, Canarium labiatum, at 22.6% on day 23 and the isopod Cymodoce sp. at 38.5% on day 46. All three species were consistently found inside the floating hapas throughout the culture period in Bolinao. The highest species diversity and number of potential predators and competitors found in hapa nets in Maliwaliw were highest during days 30 and 62. The isopod Cymodoce sp. dominated the potential predators and competitors of sandfish juveniles in Maliwaliw and made up 83.3%, 95.7% and 40.6% of taxa on days 20, 45 and 62, respectively (Table 1b). This was followed by Acetes sp. on days 30 (62.2%) and 62 (31.1%).2FIGUREThe four most abundant competitors of sandfish, Holothuria scabra, recorded in this study: (A) adult opisthobranch Stylocheilus striatus and juvenile (A.1); (B) Samar conch Canarium labiatum; (C) isopod Cymodoce sp.; and (D) Acetes sp.; and potential predators (E and F) portunid crabs Thalamita spp.; and (G) Pelates quadrilineatus.Growth and survival of sandfish juvenilesMean length, growth rate and survival of sandfish juveniles reared in floating hapas in Bolinao and in Maliwaliw at different comparable monitoring points are shown in Table 2. Differences in mean lengths and AGR of sandfish juveniles reared at Bolinao and Maliwaliw were significantly different at the first monitoring point (Student's t‐test, p < 0.001; day 23 at Bolinao and day 20 at Maliwaliw). Juveniles reared at Bolinao were significantly larger and grew faster compared to those reared at Maliwaliw at this point. Differences in mean length (Student's t‐test, p = 0.35) and AGR (Student's t‐test, p = 0.64) of sandfish juveniles reared at Bolinao and Maliwaliw were not significant on day 45 (Table 2). By day 67, mean length (Student's t‐test, p = 0.003) and AGR (Student's t‐test, p = 0.014) of sandfish juveniles reared at Maliwaliw were significantly higher than those reared in Bolinao (Table 2). Survival was high at both sites across all comparable monitoring points, and differences between the two sites were not significant by day 67 (Student's t‐test, p = 0.24; Table 2).2TABLEAverage (±SE) length (mm), absolute growth rates (mm day−1) and survival (%) of sandfish Holothuria scabra juveniles reared in floating hapas at Bolinao and MaliwaliwSiteMonitoring periodAve. length (mm)AGR (mm day−1)Survival (%)BolinaoD2331.3 ± 1.3a1.17 ± 0.06a65.12 ± 2.70D4631.96 ± 1.10a0.03 ± 0.10a95.24 ± 0.99D6746.7 ± 0.15b0.64 ± 0.08b96.16 ± 1.89aMaliwaliwD2017.7 ± 0.60b0.60 ± 0.06bD3028.8 ± 2.40.77 ± 0.0852.28 ± 8.09D4530.22 ± 1.35a0.09 ± 0.09aD6258.8 ± 2.4a1 ± 0.08a96.7 ± 0.65aNote:Significant differences between sites within each comparable monitoring period are indicated by superscript with different letters within each parameter.Abbreviation: AGR, absolute growth rate.A significantly negative correlation between the number of potential predators/competitors and survival of sandfish juveniles was observed at Bolinao (Table 3; r = −0.7949, r2 = 0.6319, p = 0.0004). Additionally, the negative correlation between potential predators/competitors and AGR of sandfish juveniles at Maliwaliw was significant (Table 3; r = −0.707, r2 = 0.4999, p = 0.0222). Conversely, no significant correlations between the number of potential predators and competitors and survival of sandfish juveniles were observed at Maliwaliw (r = −0.2881, r2 = 0.083, p = 0.4196,). Similarly, no correlation was observed between potential predators and competitors counts and AGR of sandfish juveniles reared at the Bolinao (r = 0.3987, r2 = 0.159, p = 0.141) site.3TABLECorrelation between potential predators/competitors (pred/comp), absolute growth rates (AGRs) and survival (Surv) of sandfish Holothuria scabra juveniles reared in Bolinao and MaliwaliwSiteParametersrr2pBolinaopred/comp: AGR0.39870.1590.141pred/comp: Surv−0.79490.63190.0004Maliwaliwpred/comp: AGR−0.7070.49990.0222pred/comp: Surv−0.28810.0830.4196DISCUSSIONThe impact of predators and competitors on culture systems is one of the major risks during large‐scale production of sandfish juveniles. This study reports for the first‐time potential predators and competitors that recruited and migrated to floating hapa nets during ocean nursery culture of sandfish juveniles reared in the Philippines. Results indicate that the presence of potential predators and competitors within the floating hapas negatively affected growth performance and survival of sandfish juveniles.Implications of potential predators and competitors on sandfish juvenilesPotential predators and competitors in this study may have recruited to hapa nets as juveniles or migrated as adults as indicated by their body sizes and life stages. For example, sizes at first sexual maturity of male and female Chacunda gizzard shad Anodontostoma chacunda are around 139 and 141 mm (Remya et al., 2009), respectively, whereas the total body length of the individual found in the present study was 205 mm. This suggests migration of an adult individual into hapa nets. Likewise, the presence of S. striatus egg ribbons attached to the inside surfaces of floating hapas indicates that some individuals had migrated into the hapa nets as adults. It is possible that the high abundance of food attracted potential competitors which in turn attracted predators to the hapa nets. It is also possible that these animals migrated and recruited to the culture units because of the refugia offered by the hapa nets. Alternatively, it is also possible that these animals were carried into the hapa nets by wave action. Periphyton assemblages serve as settlement cues for various species of marine invertebrates (Qian et al., 2007); thus, it is possible that the oyster Crassostrea sp. (13–17 mm) juveniles in the present study may have settled as larvae within the hapa nets.Based on their feeding habit and diet, 26.9% of the 26 species found within the hapa nets were herbivores and omnivores (mostly feeding on microalgae, zooplankton and small crustaceans). These animals compete with juvenile sandfish for food and living space, negatively affecting growth performance of sandfish juveniles as demonstrated by data reported here for Maliwaliw during the first 30 days of rearing. The periphyton assemblages which provide the primary source of food for sandfish juveniles in the floating hapas typically begin to decline by day 20 (Gorospe et al., 2020, 2020). Thus, regular net change is necessary to ensure that food within the culture system is high and is always available to support growth of sandfish juveniles. Hapa nets at Maliwaliw were only changed once during the entire culture period, and thus, it is possible that food abundance was low in these hapas. This situation could have been further exacerbated by the high number of competitors that recruited to the hapas, thereby increasing intra‐ and interspecific competition for food. S. striatus, for example, have been shown to consume up to ∼17.49 mg individual−1 day−1 (dry weight) of periphyton compared to ∼4.92 mg individual−1 day−1 (dry weight) of periphyton consumed by H. scabra juveniles (Gorospe et al., 2021).Juveniles of carnivorous portunid crabs (7.3–13.9 mm) were also found inside the hapa nets at both sites. Adults of portunid crabs such as Thalamita crenata and Portunus pelagicus have been reported to prey on sandfish (Eeckhaut et al., 2020; Francour, 1997); however, there was no indication that juvenile Thalamita spp. crabs found within the hapa nets preyed on sandfish contained therein. Similarly, there were no indications that a juvenile Pelates quadrilineatus (a carnivorous fish found within the floating hapas) was preying on sandfish during monitoring periods, indicating the importance of size in predator‐prey interactions. It is unlikely that Thalamita sp. crabs (7.5–13 mm) and the four‐lined terapon P. quadrilineatus (24.3 mm) juveniles could prey on the sandfish juveniles (28.8–58.8 mm) due to the relatively small size of the potential predators compared to the larger sandfish juveniles in the present study. The isopod Cymodoce sp. has been reported to infest the skin of sandfish juveniles reared in ponds during summer months, causing ulceration and high mortality (Lavitra et al., 2009); however, no visible skin ulcerations or lesions were observed in sandfish juveniles at either study site in this study.Although there was no direct observation of predation on sandfish juveniles during the monitoring points used in this study, the significantly negative correlation between the number of potential predators/competitors present and sandfish juvenile survival observed in Bolinao, and the negative trend in Maliwaliw particularly during the early culture period, suggests a higher vulnerability of small post‐settled sandfish juveniles to predation. Compared to sub‐adults and adults, post‐settled sandfish juveniles are more vulnerable to predation pressure and parasites because of their small size and relatively thin body wall. Percentage survival was high during the succeeding monitoring points (i.e. days 45 and 69) at both sites. This could be attributed to the larger body size and thicker body walls of juveniles at this stage, providing some advantage against predation and competition. Releasing larger individuals into the floating hapa nets have been shown to enhance survival of sandfish juveniles (Altamirano & Noran‐Baylon, 2020). However, results of their study also showed that small juveniles (0.05–0.99 g) had higher survival than those from the mixed treatment (0.05–3.00 g). Although releasing larger individuals in floating hapa nets may have some advantages, the production cost associated with growing sandfish juveniles in the hatchery until they reach 1–3 g is high. Thus, good management of culture system which includes regular monitoring of hapa nets and removal of potential predators and competitors are as important to survival as the release size of juveniles.Predation, competition and parasite infestation affect the economic viability and profitability of cultured animals (Costello, 2009). Reducing or eliminating the negative impacts of these threats is critical to the success of sandfish culture. Predation managements, including the use of chemicals (Phillips, 2000; Pathak et al., 2000) and biocontrol (Vaughan et al., 2018; Lavitra et al., 2009) tanks, are common practice in aquaculture systems such as inland and brackish water ponds. However, such mitigation measures may not be practical nor economical in sandfish culture, because of the nature of ocean culture systems and the diversity of animals which recruit to hapa nets. Non‐destructive and non‐chemical predation management, such as routine checking and monitoring of hapa nets and physical removal of potential predators and competitors, may be the best option for predator and competitor management in floating hapa‐based ocean nursery production systems for sandfish juveniles.Results of this study have implications for the selection of sites used for ocean nursery culture of sandfish. For example, areas with high abundances of the isopod Cymodoce sp. such as those in eutrophic waters (e.g. fish farms) should be avoided. Additionally, areas frequented by Thalamita spp. crabs, such as mangrove areas, should be avoided. Finally, further studies on the effects of size in predator‐prey interactions and the spatio‐temporal variability in recruitment patterns of potential predators and competitors in floating hapas nursery systems within dissimilar environments should be conducted.AUTHOR CONTRIBUTIONJay R. Gorospe: Conceptualization; Data curation; Formal analysis; Investigation; Methodology; Visualization; Writing‐original draft. Racelle Rescordado: Data curation; Formal analysis; Investigation; Validation; Visualization; Writing‐review & editing. Marie Antonette Juinio‐Menez: Conceptualization; Methodology; Project administration; Supervision; Writing‐review & editing. Margarita de la Cruz: Conceptualization; Methodology, Project administration; Supervision; Writing‐review & editing. Paul C. Southgate: Conceptualization; Funding acquisition; Methodology; Project administration; Supervision; Writing‐review & editing.ACKNOWLEDGEMENTSThis research was funded by the Australian Centre for International Agricultural Research (ACIAR) and was conducted as part of project FIS/2016/122 “Increasing technical skills supporting community‐based production of sea cucumber production in Vietnam and the Philippines”, led by the University of the Sunshine Coast. The authors are grateful to Garry Bucol, Josh Caasi, Tirso Catbagan, Jonh Rey Gacura, Joyce Laurente and Janine Villamor for their assistance during field monitoring and to Dr. Monal Lal for his comments. We would also like to thank the Guiuan Marine Fisheries Development Center of the Bureau of Fisheries and Aquatic Resources Region 08 for providing the post‐settled sandfish juveniles used at the Maliwaliw site.CONFLICT OF INTEREST STATEMENTThe authors declare that they have no conflict of Interests.DATA AVAILABILITY STATEMENTThe data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.ETHICS STATEMENTNo ethics approval is required for sandfish Holothuria scabra, however, I pledge that the animals in this study were treated carefully and humanely and the methods were designed in a way which minimized any harm or suffering of the animals.PEER REVIEWThe peer review history for this article is available at: https://publons.com/publon/10.1002/aff2.104REFERENCESAdhiambo, N.J. (2009) Food web structure in a tropical mangrove‐seagrass ecosystem in Kenya. Thesis Dissertation. University of Nairobi.Altamirano, J.P., Sinsona, M.J., Caasi, O.J.C., dela Cruz, M., Uy, W.H., Noran‐Baylon, R. et al. (2021) Factors affecting the spatio‐temporal variability in the production of sandfish Holothuria scabra in floating hapa ocean nursery systems. Aquaculture, 541, 736743. https://doi.org/10.1016/j.aquaculture.2021.736743Altamirano, J.P. & Noran‐Baylon, R. (2020) Nursery culture of sandfish Holothuria scabra in sea‐based floating hapa nets: effects of initial stocking density, size grading and net replacement frequency. Aquaculture, 526, 735379.Anderson, S.C., Flemming, J.M., Watson, R. & Lotze, H.K. (2011) Serial exploitation of global sea cucumber fisheries. Fish and Fisheries, 12, 317–339.Arrontes, J. (1990) Diet, food preference and digestive efficiency in intertidal isopods inhabiting macroalgae. Journal of Experimental Marine Biology and Ecology, 139(3), 231–249. https://doi.org/10.1016/0022‐0981(90)90149‐7Battaglene, S.C., Seymour, J.E. & Ramofafia, C. (1999) Survival and growth of cultured juvenile sea cucumbers, Holothuria scabra. Aquaculture, 178, 293–322.Bowman, W.M. (2012) Sandfish production and development of sea ranching in northern Australia. In: Hair, C.A., Pickering, T.D. & Mills, D.J. (Eds.) Asia–Pacific tropical sea cucumber aquaculture. Proceedings of an International Symposium Held in Noumea, New Caledonia, 15–17 February 2011. Canberra: Australian Centre for International Agricultural Research, pp. 75–78.Cannicci, S., Dahdouh‐Guebas, F., Anyona, D. & Vannini, M. (1996) Natural diets and feeding habits of Thalamita crenata (Decapoda; Portunidae). Journal of Crustacean Biology, 16(4), 678–683.Checon, H.H., Pardo, E.V. & Amaral, A.C.Z. (2017) Breadth and composition of polychaete diets and the importance of diatoms to species and trophic guilds. Helgoland Marine Research, 70, 19. https://doi.org/10.1186/s10152‐016‐0469‐4Costello, M.J. (2009) The global economic cost of sea lice to the salmonid farming industry. Journal of Fish Diseases, 32(1), 115–118. https://doi.org/10.1111/j.1365‐2761.2008.01011.xEeckhaut, I., Février, J., Todinanahary, G. & Delroisse, J. (2020) Impact of Thalamita crenata (Decapoda; Portunidae) predation on Holothuria scabra juvenile survival in sea farming pens. SPC Beche‐de‐Mer, Information Bulletin, 40. 11–16.Francour, P. (1997) Predation on holothurians: a literature review. Invertebrate Biology, 116, 52–60.Gorospe, J.C., MA, J.M. & Southgate, P.C. (2020) Is culture performance of juvenile sandfish, Holothuria scabra, in ocean‐based nursery systems influenced by proximity to milkfish (Chanos chanos) farms and hapa net mesh size? Aquaculture, 531(395), 735812. https://doi.org/10.1016/j.aquaculture.2020.735812Gorospe, J.C., Juinio‐Meñez, M.A. & Southgate, P.C. (2021) Influence of intra‐ and interspecific competition on periphyton biomass and growth performance of Holothuria scabra juveniles. Bulletin of Marine Science, 97(4), 631–646.Hair, C., Mills, D.J., McIntyre, R. & Southgate, P.C. (2016) Optimising methods for community‐based sea cucumber ranching: experimental releases of cultured juvenile Holothuria scabra into seagrass meadows in Papua New Guinea. Aquaculture Reports, 3, 198–208.Hajisamae, S., Chou, L.M. & Ibrahim, S. (2004) Feeding habits and trophic relationships of fishes utilizing an impacted coastal habitat, Singapore. Hydrobiologia, 520, 61–71.Hawkins, A.J.S., Smith, R.F.M., Tan, S.H. & Yasin, Z.B. (1998) Suspension‐feeding behaviour in tropical bivalve molluscs: Perna viridis, Crassostrea belcheri, Crassostrea iradelei, Saccostrea cucculata and Pinctada margarifera. Marine Ecology Progress Series, 166, 173–185.Hobson, E.S. & Chess, J.R. (1973) Feeding oriented movements of the atherinid fish Praneus pinguis at Majuro Atoll, Marshall Islands. Fishery Bulletin, 71(3), 777–786.Hutchins, J.B. (1997) Review of the monacanthid fish genus Paramonacanthus, with descriptions of three new species. Records of the Western Australian Museum, 54. 1–57.Juinio‐Meñez, M.A., Evangelio, J.E., Miralao, S.J. (2014) Trial grow‐out of the sea cucumber Holothuria scabra in sea pens and cages. Aquaculture Research, 45, 1332–1340.Juinio‐Meñez, M.A., Evangelio, J.E., Olavides, R.O., Paña, M.A.S., de Peralta, G.M., Edullantes, C.M.A. et al. (2013) Population dynamics of cultured Holothuria scabra in a sea ranch: implications for stock restoration. Reviews in Fisheries Science, 21(3–4), 424–432.Juinio‐Meñez, M.A., de Peralta, G.M., Dumalan, R.P., Edullantes, C.A. & Catbagan, T. (2012) Ocean nursery systems for scaling up juvenile sandfish (Holothuria scabra) production: ensuring opportunities for small fishers. In: Hair, C.A., Pickering, T.D. & Mills, D.J. (Eds.) Asia–Pacific tropical sea cucumber aquaculture. Proceedings of an International Symposium Held in Noumea, New Caledonia, 15–17 February 2011. Canberra: Australian Centre for International Agricultural Research, pp. 57–62.Kamukuru, A.T. & Mgaya, Y.D. (2004) The food and feeding habits of blackspot snapper, Lutjanus fulviflamma (Pisces: Lutjanidae) in shallow waters of Mafia Island, Tanzania. African Journal of Ecology, 42(1), 49–58.Kennish, R., Williams, G.A. & Lee, S.Y. (1996) Algal seasonality on an exposed rocky shore in Hong Kong and the dietary implications for the herbivorous crab Grapsus albolineatus. Marine Biology, 125(1), 55–64.Kohler, K.E., & Gill, S.M. (2006) Coral Point Count with Excel extensions (CPCe): a visual basic program for the determination of coral and substrate coverage using random point count methodology. Computers and Geosciences, 32, 1259–1269. https://doi.org/10.1016/j.cageo.2005.11.009Lavitra, T., Rasolofonirina, R., Jangoux, M. & Eeckhaut, I. (2009) Problems related to the farming of Holothuria scabra (Jaeger, 1833). SPC Beche‐de‐Mer Information Bulletin, 29. 20–30.Marte, C.L. (1980) The food and feeding habit of Penaeus monodon Fabricius collected from Makato River, Aklan, Philippines (Decapoda Natantia). Crustaceana, 38(3), 225–236.Masterson, J. (2008) Bursatella leachii. In Smithsonian Marine Station at Fort Pierce. http://www.sms.si.edu/irlspec/Bursatella_leachii.htmMetillo, E., Cadelinia, E., Hayashizaki, K., Tsunoda, T. & Nishida, S. (2015) Feeding ecology of two sympatric species of Acetes (Decapoda: Sergestidae) in Panguil Bay, the Philippines. Marine and Freshwater Research, 67, 1420–1433. https://doi.org/10.1071/MF15001Paige, J.A. (1988) Biology, Metamorphosis and Postlarval Development of Bursatella leachii Plei Rang (Gastropoda: Opisthobranchia). Bulletin of Marine Science, 42(1): 65–75.Paul, V.J. & Pennings, S.C. (1991) Diet‐derived chemical defences in the sea hare Stylocheilus longicauda (Quoy et Gaimard 1824). Journal of Experimental Marine Biology and Ecology, 151(2), 227–243. https://doi.org/10.1016/0022‐0981(91)90126‐HPathak, S.C., Ghosh, S.K. & Palanisamy, K. (2000) The use of chemicals in aquaculture in India. In: Arthur, J.R., Lavilla‐Pitogo, C.R. & Subasinghe, R.P. (Eds.) Use of chemicals in aquaculture in Asia. Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20–22 May 1996. Tigbauan, Iloilo, Philippines.Pennings, S.C., Nadeau, M.T. & Paul, V.J. (1993) Selectivity and growth of the generalist herbivore Dolabella auricularia feeding upon complementary resources. Ecology, 74(3), 879–890.Phillips, M. (2000) The use of chemicals in carp and shrimp aquaculture in Bangladesh, Cambodia, Lao PDR, Nepal, Pakistan, Sri Lanka and Viet Nam. In: Arthur, J.R., Lavilla‐Pitogo, C.R. & Subasinghe, R.P. (Eds) Use of chemicals in aquaculture in Asia. Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20–22 May 1996. Tigbauan, Iloilo, Philippines.Purcell, S.W. (2014) Value, market preferences and trade of bêche‐de‐mer from Pacific Island sea cucumbers. PLoS One, 9(4), e95075.Qian, P.Y., Lau, S.C.K., Dahms, H.U., Dobretsov, S., Harder, T. (2007) Marine biofilms as mediators of colonization by marine macroorganisms: implications for antifouling and aquaculture. Marine Biotechnology, 9. 399–410.Ramofafia, C., Byrne, M. & Battaglene, S.C. (2003) Reproduction of the commercial sea cucumber Holothuria scabra (Echinodermata: Holothuroidea) in the Solomon Islands. Marine Biology, 142, 281–288.Remya, V.C., Benakappa, S., Mahesh, V., Kumar Naik, A.S., Anjanayappa, H.N. & Vijaykumar, M.E. (2009) Breeding seasonality of Anodontostoma chacunda (Hamilton, 1822) off Mangalore coast, Karnataka, India. Indian Journal of Geo Marine Sciences, 48(05), 628–634.Sano, M., Shimizu, M., & Nose, Y. (1984) Food habits of teleostean reef fishes in Okinawa Island, southern Japan. University of Tokyo Bulletin, vol. 25. Tokyo, Japan: University of Tokyo Press, pp 128.Sinsona, M.J. & Juinio‐Meñez, M.A. (2019) Periphyton characteristics influence the growth and survival of Holothuria scabra early juveniles in an ocean nursery system. Aquaculture Research, 50, 2655–2665. https://doi.org/10.1111/are.14223.Taylor, A.L., Nowland, S.J., Hearnden, M.N., Hair, C.A. & Fleming, A.E. (2016) Sea ranching release techniques for cultured sea cucumber Holothuria scabra (Echinodermata: Holothuroidea) juveniles within the high‐energy marine environments of Northern Australia. Aquaculture, 456, 109–116. https://doi.org/10.1016/j.aquaculture.2016.08.031Vaughan, D.B., Grutter, A.S. & Hutson, K.S. (2018) Cleaner shrimp remove parasite eggs on fish cages. Aquaculture Environment Interactions, 10, 429–436. https://doi.org/10.3354/aei00280Whitehead, P.J.P. (1985) Clupeoid fishes of the world (suborder Clupeoidei). An annotated and illustrated catalogue of the herrings, sardines, pilchards, sprats, shads, anchovies and wolfherrings, vol. 125(7/1). FAO Species Catalogue. Rome: FAO, pp. 1–303.Woodland, D.J. (1990) Revision of the fish family Siganidae with descriptions of two new species and comments on distribution and biology. Indo‐Pacific Fishes, 19, 136Woodland, D. (1997) Siganidae. Rabbitfishes (spinefoots). In Carpenter, K.E. & Niem, V. (Eds.) FAO identification guide for fishery purposes. The Western Central Pacific, Rome: FAO, pp. 3627–3650.
Aquaculture Fish and Fisheries – Wiley
Published: Jun 1, 2023
Keywords: juveniles; ocean nursery; periphyton; predation; sea cucumber
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