Global knowledge on the commercial sea cucumber Holothuria scabra

Hamel, Jean‐François; Eeckhaut, Igor; Conand, Chantal; Sun, Jiamin; Caulier, Guillaume; Mercier, Annie

doi:10.1016/bs.amb.2022.04.001

Cited by 28 publications

(28 citation statements)

References 295 publications

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“…Globally, non‐sustainable harvesting of holothurians is now widespread and ongoing (Anderson et al, 2011; Cariglia et al, 2013; Conand, 2018; Hasan, 2019; Hamel et al, 2022). Within the Central/Western Indian Ocean high fishing pressure on holothurians (sea cucumbers) is potentially leading to overexploitation in many countries (Eriksson et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Boom‐and‐bust cycles of holothurian (sea cucumber) populations in the Chagos Archipelago: An indication of poaching or natural processes?

Widman

Collins

Evans

et al. 2023

Aquatic Conservation

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The Chagos Archipelago is a remote Indian Ocean atoll of international conservation significance. Holothurians (sea cucumbers) are a major resource and influence reef health. Past populations have fluctuated from poaching and natural events. Visual censuses of holothurians were conducted in 62 shallow‐water transects within four atolls of Chagos in 2014, 4 years after creation of the Marine Protected Area, to determine its possible influence on holothurians. Comparison with data from the same locations in 2006 and 2010, using the same methodologies, showed significant overall population decline at Diego Garcia, recovery at Salomon (significant) and Peros Banhos (not significant), and no significant change on the Great Chagos Bank. The median abundance of Holothuria atra and Bohadschia sp(p.) decreased at Diego Garcia, while that of Stichopus chloronotus increased at Diego Garcia and Salomon atolls. Changes for other species were less marked. Diego Garcia, Salomon and Peros Bahnos showed a decline in diversity (no. of holothurian taxa and/or Shannon index, H), but diversity has been relatively stable on the Great Chagos Bank. All atolls, except Diego Garcia, are uninhabited and illegal fishing of holothurians, principally by Sri Lankan fishers, appears to have eased since 2005/2006, based on evaluation of 299 patrol survey reports. This may have led to the recovery or stabilization of populations in the outer atolls of Salomon, Peros Banhos atolls and the Great Chagos Bank. The reasons for holothurian decline at Diego Garcia, where exploitation is also prohibited (but cannot be ruled out), are unclear. Population patterns on all islands may reflect both natural fluctuations and disturbance events, including changing exploitation pressure. Conservation requirements include periodic re‐censusing of holothurians and ongoing monitoring of illegal fishing to help safeguard populations and the integrity of the Marine Protected Area.

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Section: Introductionmentioning

confidence: 99%

Boom‐and‐bust cycles of holothurian (sea cucumber) populations in the Chagos Archipelago: An indication of poaching or natural processes?

Widman

Collins

Evans

et al. 2023

Aquatic Conservation

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“…Late auricularia is a competent stage sand sh larvae that is physiologically ready to metamorphose if stimulated properly (Hamel et al 2022). Further, transformation to doliolaria larvae until pentactula or the post settled stage is an indication of larvae competence to metamorphose.…”

Section: Metamorphic Competency and Post Settlement Successmentioning

confidence: 99%

“…Currently, many countries in the Indo-Paci c and Southern Africa are undertaking sand sh culture at varying scales (Jimmy et al 2012;Mills et al 2012;Hamel et al 2022).…”

Section: Introductionmentioning

confidence: 99%

Metamorphic success and production cost of Holothuria scabra reared on microalgal concentrates compared with live microalgae

Garpa

Caasi

Juinio‐Meñez

2023

Preprint

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Larval food is a bottleneck in the culture of Holothuria scabra. Whether larval metamorphic success and juvenile production can be improved using microalgae concentrates was investigated. Larvae were reared under a fixed daily feeding ration of 20,000 cells mL-1 using three commercial concentrates (Instant Algae®, Reed Mariculture Inc.): TW1200 (Thalassiosira weisflogii; TW), TISO1800 (Isochrysis sp.; TISO), and Shellfish1800 (mixed diatom; SHELL) and compared with live Chaetoceros calcitrans (CC). The diet efficacy was evaluated based on larval development rate, sizes and survival to late auricularia (LA) with hyaline spheres (HS), and post settlement. Larvae in TW did not progress beyond LA. The average size during LA in TISO (855.7 ± 62.67µm) was significantly higher compared with SHELL. Larvae fed CC reached LA stage earlier, attained significantly larger sizes (1028.43 ± 19.38 µm), and have significantly higher incidence and size of HS. Better metamorphic and settlement performance in CC and SHELL may be related to the higher carbohydrate content in these feeds. The average number of post-settled juveniles in CC (9,268 ± 2,183.79) was over three times more than in SHELL, and an order of magnitude for TISO. Because of the low juvenile yield and longer feeding duration, the estimated cost of producing each juvenile using SHELL is PhP 2.00 and PhP 11.77 for TISO, compared to PhP 0.52 using CC. Development of local microalgal concentrates can enable more hatcheries to undertake sandfish culture, and access to more affordable supplemental feed to promote higher post settlement success.

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“…Late auricularia is a competent stage of sand sh larvae that is physiologically ready to metamorphose if stimulated properly (Hamel et al 2022). Further, transformation to doliolaria larvae until pentactula or the post settled stage is an indication of larvae competence to metamorphose.…”

Section: Metamorphic Competency and Post Settlement Successmentioning

confidence: 99%

“…H. scabra is highly suitable for aquaculture due to its short larval phase, wide temperature and salinity tolerance, and high-value end product (Hamel et al 2001;Pitt and Duy 2004). Many Indo-Paci c countries and some areas in Southern Africa such as Madagascar are undertaking sand sh culture at varying scales (Jimmy et al 2012;Mills et al 2012;Hamel et al 2022).…”

Section: Introductionmentioning

confidence: 99%

Metamorphic and post-settlement success of Holothuria scabra reared on microalgal concentrates compared with live microalgae

Garpa

Caasi

Juinio‐Meñez

2022

Preprint

View full text Add to dashboard Cite

Commercially available microalgae concentrates used in the culture of Holothuria scabra were compared to live microalgae. Larvae were reared under a fixed daily feeding ration of 20,000 cells mL− 1 using three commercial concentrates (Instant Algae®, Reed Mariculture Inc.): TW 1200 (Thalassiosira weisflogii; TW), TISO 1800 (Isochrysis sp.; TISO), and Shellfish 1800 (mixed diatom; SHELL) and compared with live Chaetoceros calcitrans (CC). The efficacy of diets was evaluated based on larval growth, development, and survival to late auricularia (LA) with hyaline spheres (HS) and post settled juveniles. The average size in TISO (855.7 ± 62.67µm) was significantly higher compared with SHELL. In contrast, larvae in TW did not progress beyond middle LA. Development was much better in CC compared to all the microalgal concentrates. Larvae fed CC reached LA stage earlier, attained significantly larger sizes (1028.43 ± 19.38 µm), and have significantly higher incidence and size of HS. Better metamorphic and settlement performance of larvae in CC and SHELL treatment maybe related to the higher carbohydrate content in these feeds. Average post settled juveniles in CC (9,268 ± 2,183.79) were over three times more in SHELL, and an order of magnitude for TISO. Higher costs per juvenile can be largely attributed to the low post settled juvenile yield and longer feeding duration when using microalgae concentrates. The estimated cost of producing each juvenile using SHELL is $0.036 and $0.210 for TISO, compared to $0.009 per juvenile using CC. Opportunities to optimize the use of microalgal concentrates as supplemental feeds are discussed.

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Global knowledge on the commercial sea cucumber Holothuria scabra

Cited by 28 publications

References 295 publications

Boom‐and‐bust cycles of holothurian (sea cucumber) populations in the Chagos Archipelago: An indication of poaching or natural processes?

Boom‐and‐bust cycles of holothurian (sea cucumber) populations in the Chagos Archipelago: An indication of poaching or natural processes?

Metamorphic success and production cost of Holothuria scabra reared on microalgal concentrates compared with live microalgae

Metamorphic and post-settlement success of Holothuria scabra reared on microalgal concentrates compared with live microalgae

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