Sea Cucumber Resources Research Articles

A novel deep-benthic sea cucumber species of Benthodytes (Holothuroidea, Elasipodida, Psychropotidae) and its comprehensive mitochondrial genome sequencing and evolutionary analysis

BackgroundThe holothurians, commonly known as sea cucumbers, are marine organisms that possess significant dietary, nutritional, and medicinal value. However, the National Center for Biotechnology Information (NCBI) currently possesses only approximately 70 complete mitochondrial genome datasets of Holothurioidea, which poses limitations on conducting comprehensive research on their genetic resources and evolutionary patterns. In this study, a novel species of sea cucumber belonging to the genus Benthodytes, was discovered in the western Pacific Ocean. The genomic DNA of the novel sea cucumber was extracted, sequenced, assembled and subjected to thorough analysis.ResultsThe mtDNA of Benthodytes sp. Gxx-2023 (GenBank No. OR992091) exhibits a circular structure spanning 17,386 bp, comprising of 13 protein-coding genes (PCGs), 24 non-coding RNAs (2 rRNA genes and 22 tRNA genes), along with two putative control regions measuring 882 bp and 1153 bp, respectively. It exhibits a high AT% content and negative AT-skew, which distinguishing it from the majority of sea cucumbers in terms of environmental adaptability evolution. The mitochondrial gene homology between Gxx-2023 and other sea cucumbers is significantly low, with less than 91% similarity to Benthodytes marianensis, which exhibits the highest level of homology. Additionally, its homology with other sea cucumbers is below 80%. The mitogenome of this species exhibits a unique pattern in terms of start and stop codons, featuring only two types of start codons (ATG and ATT) and three types of stop codons including the incomplete T. Notably, the abundance of AT in the Second position of the codons surpasses that of the First and Third position. The gene arrangement of PCGs exhibits a relatively conserved pattern, while there exists substantial variability in tRNA. Evolutionary analysis revealed that it formed a distinct cluster with B. marianensis and exhibited relatively distant phylogenetic relationships with other sea cucumbers.ConclusionsThese findings contribute to the taxonomic diversity of sea cucumbers in the Elasipodida order, thereby holding significant implications for the conservation of biological genetic resources, evolutionary advancements, and the exploration of novel sea cucumber resources.

Community structure of sea cucumber (Echinodermata: Holothuroidea) resources in the Kepulauan Seribu National Park, Indonesia

Abstract. Helmiyani NA, Suryanti S, Purwanti F. 2024. Community structure of sea cucumber (Echinodermata: Holothuroidea) resources in the Kepulauan Seribu National Park, Indonesia. Biodiversitas 25: 344-354. Kepulauan Seribu National Park has several types of commercial sea cucumbers (Echinodermata: Holothuroidea). Many local and foreign communities take sea cucumbers from nature without paying attention to habitat conditions. This phenomenon causes a decrease in the availability of sea cucumbers. This research was carried out to help stabilize the sea cucumber ecosystem and its availability to be considered for its sustainability. This research was conducted in May-June 2023, at Kelapa Dua Island and Panjang Kecil Island in the Kepulauan Seribu National Park, Jakarta, Indonesia. Sampling was carried out using the field observation method, where the location points were determined by adjusting where the sea cucumber habitat was located. Sampling points were carried out on two islands, each island was assigned 4 station points, with the total number of stations on both islands being 8 station points. Sampling was carried out using perpendicular transect lines, divided into 3 zones. The data analyzed includes the Index of Diversity, Evenness, Dominance and Density. Based on the results 12 species were obtained from both islands, with the genera Holothuria, Stichopus, Bohadschia, Actinopyga, and Synapta. The highest density is at station 3 Kelapa Dua Island, with a density value of 0.57 (ind/m2), and the lowest density is at station 1 Panjang Kecil Island with a value of 0.14 (ind/m2). The results show a moderate diversity value, a low Dominance value, and a small evenness value, while the water quality result value can be said to be good because it has a value according to the survival quality standards for sea cucumbers in marine waters.

Diversity and abundance of sea cucumber (Holothuroidea) resources in the Waters of Duroa Island, Tual City, Maluku, Indonesia

Abstract. Kalidi NS, Muskananfola MR, Suryanti S. 2023. Diversity and abundance of sea cucumber (Holothuroidea) resources in the Waters of Duroa Island, Tual City, Maluku, Indonesia. Biodiversitas 24: 6002-6009. The people of Duroa Island, Tual City, Indonesia, have been utilizing sea cucumber resources continuously without considering its impact on ecological factors and sustainability. Formulating management initiatives is one possible solution to sustain the stock. However, it is hampered by the lack of information on its current status. This study aims to assess the abundance and diversity as well as the condition of the aquatic environment. In the observation 9 sea cucumbers were found from Holothuria, Bohadschia, Actinopyga, Stichopus, and Thelenota genera. The density of sea cucumber was highest at station 4 (0.417 ind/m²), and lowest at station 1 (0.083 ind/m²). Holothuria edulis dominated the sea cucumber community at a density of (0.450 ind/m2). Habitat characteristics of sea cucumber observation stations on Duroa Island are dominated by seagrass, rocky sand, rough sand, and sand. Ecological indices such as diversity are classified as moderate, high uniformity, and low dominance. All observation stations have water quality that is still in the optimal range according to water quality standards for marine biota, except at station 1 because the station has a pH value below the national quality standard of <6.5.

EFISIENSI KINERJA SASI TERIPANG PASIR (Holothuria scabra) DESA TUNGU KEPULAUAN ARU

The sandfish sea cucumber, Holothuria scabra, has economic value and is considered expensive, making it a target for utilization. The sandfish sea cucumber is found in the village of Tungu, but with the implementation of sasi (a traditional system of resource management), it is expected to ensure the sustainability of the sandfish sea cucumber resources. In reality, every time the sasi period is lifted, sandfish sea cucumbers are harvested without any size limitations and there are illegal captures by fishermen from outside the Aru Islands using complete diving equipment. Given these conditions, it is suspected that the sandfish sea cucumber population may decline. Therefore, this research was conducted in August-September 2018, with the aim of assessing the performance efficiency of the sasi system for sandfish sea cucumbers in Tungu Village. Data collection was done through observation and interviews with intentionally selected respondents and analyzed descriptively using several indicators. The research results showed that the catch of sandfish sea cucumbers amounted to 2,240 kg of dried weight, with varying selling prices according to size. The analysis of performance efficiency indicated that the sasi system for sandfish sea cucumbers in Tungu Village falls into the moderate category.

PENGENALAN TERIPANG DAN MANFAATNYA DI PERAIRAN HUTUMURI BAGI SISWA SMP NEGERI 8 AMBON

Hutumuri waters have sea cucumber resources, but their utilization is still limited. However, there are exploitation activities of their habitat. Therefore, the community service activity was carried out, which aimed to provide knowledge and increase the role of SMP Negeri 8 Ambon students in conserving sea cucumber resources. The activity was conducted online by using various lecture methods, video playback, discussion and sharing of experiences by students, and provision of ebooks. The results of the evaluation by the pre-test and post-test indicated that the knowledge of students increased about the important of sea cucumber. It is expected that this activity will motivate students to be sustainable agent who play an important role to maintain the sustainability of sea cucumber resources and both coastal and marine ecosystems.

Bisphenol A (BPA) Directly Activates the G Protein-Coupled Estrogen Receptor 1 and Triggers the Metabolic Disruption in the Gonadal Tissue of Apostichopus japonicus.

The sea cucumber, Apostichopus japonicus, is a marine benthic organism that feeds on small benthic particulate matter and is easily affected by pollutants. Bisphenol A (BPA, 4,4'-isopropylidenediphenol) has been identified as an endocrine disruptor. It is ubiquitously detectable in oceans and affects a variety of marine animals. It functions as an estrogen analog and typically causes reproductive toxicity by interfering with the endocrine system. To comparatively analyze the reproductive effects of estradiol (E2) and BPA on sea cucumbers, we identified a G protein-coupled estrogen receptor 1 (GPER1) in A. japonicus and investigated its effects on reproduction. The results showed that BPA and E2 exposure activated A. japonicus AjGPER1, thereby mediating the mitogen-activated protein kinase signaling pathways. High-level expression of AjGPER1 in the ovarian tissue was confirmed by qPCR. Furthermore, metabolic changes were induced by 100 nM (22.83 μg/L) BPA exposure in the ovarian tissue, leading to a notable increase in the activities of trehalase and phosphofructokinase. Overall, our findings suggest that AjGPER1 is directly activated by BPA and affects sea cucumber reproduction by disrupting ovarian tissue metabolism, suggesting that marine pollutants pose a threat to the conservation of sea cucumber resources.

Fishermen's perception and participation towards management and utilization of sea cucumber in Kepulauan Seribu National Park, Indonesia

Kepulauan Seribu National Park has sea cucumber resources that have high economic value, many people utilize sea cucumbers as a source of livelihood. This study aims to determine how fishermen view the management of sea cucumbers and as actors of their utilization in the Kepulauan Seribu National Park. The management of sea cucumbers in the Kepulauan Seribu National Park, this research analyzes the data that is carried out is the processing of sea cucumber resource data. This research was conducted in May-June 2023 in Kelapa Island Village, North Kepulauan Seribu National Park. The methods used in this research are observation and interview methods, then distributing questionnaires, with the determination of respondents using the snowball sampling method. The analysis used is using the Likert method then used to conduct a qualitative analysis of community aspirations and participation in determining commercial sea cucumber management strategies based on the results of interviews. The results show that the community still does not know and has not participated much regarding Management, Determination of fishing regulations.

Integrative Application of Transcriptomics and Metabolomics Provides Insights into Unsynchronized Growth in Sea Cucumber (Stichopus monotuberculatus).

Ever-increasing consumer demand for sea cucumbers mainly leads to huge damage to wild sea cucumber resources, including Stichopus monotuberculatus, which in turn exerts negative impacts on marine environments due to the lack of ecological functions performed by sea cucumbers. Aquaculture of sea cucumbers is an effective way to meet consumer demand and restore their resources. Unsynchronous growth is a prominent problem in the aquaculture of sea cucumbers which has concealed unelucidated molecular mechanisms until now. In this study, we carried out an integrative analysis of transcriptomics and metabolomics on fast-growing (SMF) and slow-growing (SMS) groups of S. monotuberculatus cultured in the same environmental conditions. The results revealed that a total of 2054 significantly differentially expressed genes (DEGs) were identified, which are mainly involved in fat digestion and absorption, histidine metabolism, arachidonic acid metabolism, and glutathione metabolism. 368 differential metabolites (DMs) were screened out between the SMF group and the SMS group; these metabolites are mainly involved in glycerophospholipid metabolism, purine metabolism, biosynthesis of unsaturated fatty acids, pyrimidine metabolism, arachidonic acid metabolism, and other metabolic pathways. The integrative analysis of transcriptomics and metabolomics of S. monotuberculatus suggested that the SMF group had a higher capacity for lipid metabolism and protein synthesis, and had a more frequent occurrence of apoptosis events, which are likely to be related to coping with environmental stresses. The results of this study provide potential values for the aquaculture of sea cucumbers which may promote their resource enhancement.

PEMBERDAYAAN EKONOMI MASYARAKAT MELALUI PEMANFAATAN TERIPANG DAN PRODUK OLAHANNYA DI NEGERI LEAHARI KOTA AMBON

The aims of this service were to increase the knowledge and skills of participants on the potential and processed sea cucumber products that can increase the economic value of sea cucumbers as well as a source of information, technology and skills that will be used by the community to support the family economy in the State of Leahari, Ambon City. The target of this activity is the community in the Leahari village, Ambon City. The method used is counseling in the form of material delivery and discussion. Increased knowledge of participants by conducting pretest and post-test. Based on the results obtained, it showed that there was an increase in the participants towards the material presented, there was a change in attitude where participants were very interested in utilizing the potential of sea cucumber resources in the Leahari village, Ambon city, to be used as processed products as new opportunities in order to improve the family economy

Hatchery-produced sandfish (Holothuria scabra) show altered genetic diversity in New Caledonia

Facing an alarming continuing decline of wild sea cucumber resources, management strategies were developed over the past three decades to sustainably promote development, maintenance, or regeneration of wild sea cucumber fisheries. In New Caledonia (South Pacific), dedicated management efforts via restocking and sea ranching programs were implemented to cope with the overharvesting of the sandfish Holothuria scabra and the recent loss of known populations. In order to investigate genetic implications of a major H. scabra restocking program, we assessed the genetic diversity and structure of wild stocks and hatchery-produced sandfish and compared the genetic outcomes of consecutive spawning and juvenile production events. For this, 1,358 sandfish collected at four sites along the northwestern coasts of New Caledonia, as well as during five different restocking events in the Tiabet Bay, were genotyped using nine polymorphic microsatellite markers. We found that wild H. scabra populations from the northwestern coast of New Caledonia likely belonged to one panmictic population with high level of gene flow observed along the study scale. Further, this panmictic population displayed an effective size of breeders large enough to ensure the feasibility of appropriate breeding programs for restocking. In contrast, hatchery-produced samples did suffer from an important reduction in the effective population size: the effective population sizes were so small that genetic drift was detectable over one generation, with the presence of inbred individuals, as well as more related dyads than in wild populations. All these results suggest that dedicated efforts in hatcheries are further needed to maintain genetic diversity of hatchery-produced individuals in order to unbalance any negative impact during this artificial selection.

Optimized pretreatment conditions for the environmental DNA (eDNA) analysis of Apostichopus japonicus

A non-destructive environmental DNA protocol for the genetic analysis of sea cucumber (Apostichopus japonicus) resources DNA was established. Among the several commercial DNA extraction kits, the DNeasy® Plant Mini Kit was selected as the best choice to obtain the high-quality genomic DNAs from the mucous sea cucumber. As the temperature and incubation time increased, the amount of extracted environmental DNA was also large, but it was judged that the increased amount did not affect as much as 2–3 times. Therefore, these conditions were not considered to be the main factors to consider in actual environmental DNA extraction. However, the amount of seawater relative to the size of the sample was judged as a major consideration, and a sufficient amount of environmental DNA for analysis was secured when stored within 1 min while stirring the volume of seawater corresponding to the total sea cucumber weight (g). In securing the environmental DNA of sea cucumbers, the mortality rate of sea cucumbers in all experiments was 0, and it was judged that the effects of sea cucumbers were not significant through this treatment. Through the results of this study, sea cucumber DNA research, which has been conducted in a destructive method, can be conducted non-destructively through environmental DNA analysis. Through this study, we have secured a standard protocol that can successfully extract the sea cucumber DNA through environmental DNA. It is not only excellent in terms of time and cost of traditional DNA analysis method currently used, but it is completely non-destructive in the ecosystem of the survey area. It is believed that the system can be transformed in a way that does not affect it. However, it is thought that various standard protocols should be established considering the characteristics of each type.

Genetic diversity of commercial sea cucumbers Stichopus (Echinoderm: Stichopodidae) based on DNA Barcoding in Karimunjawa, Indonesia

Abstract. Sulardiono B, Hartoko A, Aini AN, Wulandari D, Budiharjo A. 2021. Genetic diversity of commercial sea cucumbers Stichopus (Echinoderm: Stichopodidae) based on DNA Barcoding in Karimunjawa, Indonesia. Biodiversitas 23: 922-927. DNA barcoding has proven a sufficient tool for species identification in varied groups of marine invertebrates, including crustaceans, mollusks, polychaetes, and echinoderms. The outdated system of morphological identification of the Stichopus spp. group is generally based on color patterns, causing confusion in identification. This study aimed to investigate genetic diversity, confirm the species identification, and examine phylogenetic relationships of the Stichopus genus (Echinoderm: Stichopodae) in the Karimunjawa Sea, by analyzing DNA sequence variation at cytochrome C oxidase subunit I (COI) in mitochondrial DNA and internal transcribed spacers (ITS). This genetic information is very helpful in inventorying and mapping commercial sea cucumber resources in Karimunjawa to support conservation efforts. Three types of sea cucumbers from the genus Stichopus were found, with different local names, namely Crengek gamete, Pace gamete, and Kuning gamete. The results of DNA extraction from the three samples showed that the DNA from soft bone tissue had a better level of purity and concentration than body tissue. The COI phylogenetic tree analysis showed that these samples with different local names were closely related to Stichopus monotuberculatus. Therefore, it is necessary to conserve the resources of the S. monotuberculatus in the management of Karimunjawa sea.

Sea Cucumbers (Holothuroidea) of Northeastern and Western Mindanao, Philippines: The Potential Role of Marine Protected Areas in Maintaining Diversity and Abundance

Marine protected areas (MPAs) are considered strategic tools in conserving biodiversity and maintaining stocks of valuable resources. We assessed sea cucumbers in five provinces in northeastern and western Mindanao to describe the state of diversity and abundance and evaluate the role of MPAs in sustaining stocks of exploited species. We identified 36 species of sea cucumbers from fishery-independent surveys on shallow reef flats and deeper reef slopes, of which 33 species (92%) belong to order Aspidochirotida and three species belong to Order Apodida. The majority are shallow-water holothurians occurring on reef flats and seagrass beds, while a few species are found along reef slopes or in fresh catches by fishers sold to local traders or processors in some sites. Nine species are considered high-value to the global trepang trade but occur at low densities, while the rest are abundant or common species with low commercial value. Species richness (S=17-30 spp.) varies across sites, but species composition similarity is relatively high (Sørensen’s SQ = 0.62-0.78). Mean population densities and variances of high-value species are significantly higher inside enforced MPAs than in non-MPA sites(t-test, p <0.05; F-test, p<0.005) across five survey sites. The abundance of high-value H. scabra in Tubajon and H. fuscogilva in Capayas Island demonstrates the critical role of MPAs in conserving biodiversity, maintaining population levels, and ensuring natural recruitment of sea cucumber resources. Urgent management measures such as formulating a national management plan, regulating harvests, and establishing no-take MPAs are recommended.

Diversity, Length-Weight Relations, and Condition Factor of Sea Cucumbers in Three Coastal Areas Along the Southern Coast of Sri Lanka: A Case Study

Economically and ecologically important ecosystems that consist of diverse finfish and shellfish resources are found along the southern coast of Sri Lanka. Thus, the current study intends in assessing the species diversity, length-weight (L-W) relationships, and condition factor of sea cucumber stocks in selected coastal sites of southern Sri Lanka. The diversity of sea cucumber species was surveyed using the systematic sampling technique in three selected sites (Bandaramulla, Mirissa, and Weligama) during February-December 2019. The growth pattern of each species was identified using a least-squares regression model computed for length-weight relationships. Fulton’s condition factor (K) was analysed for each species. There were four common sea cucumber species (Holothuria atra - Lolly Fish, Bohadschia marmorata - White Thread fish, Actinipyga miliaris- Deep Water Blackfish, and Thelenota ananas- Prickly Redfish) in study sites, while Holothuria atra and Bohadschia marmorata were recorded as the most abundant species. The length-weight relationship derived for the above four species exhibited a negative allometric growth pattern (“b” < “3”), indicating faster length increment compared to weight. The habitat qualities of all sea cucumber species were in optimum environmental condition. Our findings would benefit as baseline data for implementing sustainable management practices of sea cucumber resources.

Habitat wise variability in the diversity of sea cucumbers in Lakshadweep Archipelago, North-Western Indian Ocean

The coral reefs of the Lakshadweep archipelago harbour significant sea cucumber resources. The paper discusses the habitat-wise variability of sea cucumbers observed during a series of surveys in this atolls. The western side lagoon areas and eastern intertidal areas of the atolls showed maximum diversity and species richness. One of the northernmost atolls of this archipelago, Kiltan showed an exceptional abundance of the green sea cucumber Stichopus chloronotus. The information provided will be useful for developing conservation strategies for this important group of coral reef dwellers.

Analysis of catching of sea cucumber (Stichopus variegatus) in Kramian islands, Sumenep regency, East Java

Kramian Island is located in the north of the Masalembu Islands, East Java. This area has good sea cucumber resources, but the rules on the prohibition of overfishing of sea cucumbers have not been implemented by the government in the Kramian Islands, so that fishing activities carried out by fishermen, continuously regardless of the type and size of sea cucumbers, can cause sea cucumbers in the wild to run out and the impact of sea cucumbers will be extinct. The research was conducted with the aim of knowing the fishing location, fishing method, sea cucumber species, number of catches, and benefits of sea cucumber catch. This research was conducted in March-June 2020. The method used in the study was observed with fishermen. The results of the discovery of the location of sea cucumbers using GPS, there were 3 types of sea cucumbers, namely Tanduk (Stichopus variegatus), Kapuk (Stichopus variegatus), and Susu (Holothuria rigida). Sea cucumber catch in March (253.4 kg), April (261.1 kg), May (124.1 kg), June (733.6 kg). The highest sea cucumber catch data occurred in June, while the lowest catch occurred in May.

Study on Community Structure of Commercial Sea Cucumber in Intertidal Zone, Southeast Moluccas, and Tual, Moluccas

HighlightEight species of sea cucumber was found in four intertidal location in Southeast Moluccas and Tual watersHolothuria atra had the highest densitySea cucumber biodiversity in Southeast Moluccas and Tual waters categorized as lowLocal culture can be used for sustainability of sea cucumber resources management AbstractA study on the community structure of sea cucumber in Southeast Moluccas and Tual needs to be done due to the important role of sea cucumber in both ecologically and economically sustainability. This study aimed to investigate the community structure of sea cucumber in this region as one of the supporting information for the utilization and management of the resources. A survey was conducted by sweeping the target area, by walking and also snorkeling. The location where each sea cucumber found was marked using a GPS, the specimen was weighed, and some were preserved for species analysis. Water quality was measured at each location, while the substrate and vegetation were recorded. This study revealed different composition of species in the investigated area. As many as 8 species of sea cucumber were found, in which four were of genus Holothuria, three were of genus Stichopus and the rest were of genus Bohadschia. Species H. atra has the highest density. In general, the diversity index was relatively low (< 2), the evenness index was 0-81 indicating that the community was depressed. Certain species dominated at most of the investigated sites (0.50-1), and a low margalef index is 0-1.7. To conclude, the community structure of sea cucumber in Tual and Southeast Moluccas was in a depressed condition.

Spatial variations in the population characteristics of sea cucumber resources in Gulf of Mannar and Palk Bay, south-east coast of India

The lack of data on population abundance, biomass and basic biological parameters of most of the sea cucumber species from Indian waters is a fundamental barrier to impose suitable management measures on these resources. A study was conducted to ascertain the sea cucumber population characteristics in two geographically distinct ecosystems (Gulf of Mannar and Palk Bay) along the south-east coast of India. The stock status of sea cucumber population was assessed both by trawl and dive surveys following standard methods on a random basis. Comparatively, a higher average density of total sea cucumbers was estimated in the Gulf of Mannar (3853±152.3 nos. ha-1) than in Palk Bay (2428.5±504.6 nos. ha-1). The species diversity, average length and weight of individual species were also higher in the Gulf of Mannar. The present study indicated significant variation in status and structure of sea cucumber resources in these two ecosystems. Hence the study warrants the emphasis of ecosystem-based management in formulating conservation measures of these resources in Indian waters.

The dynamics of institutional innovation: Crafting co-management in small-scale fisheries through action research

This paper investigates the dynamics of institutional development and co-management performance in small-scale fisheries. The study covers different contexts and spatial and temporal scales, for nine case studies in the South Pacific. In these cases, new co-management institutions were intentionally set up from 2008 to 2016 through fishery policy intervention to address over-exploitation problems of sea cucumber resources. This was carried out in a process of adaptive experimentation, based on a collaborative and problem-solving approach to governance, and a context-based vision of sustainability issues. In order to quantitatively and empirically assess change in governance within and between cases, a multidimensional analytical framework of governance performance is developed. A set of governance performance criteria is defined and the criteria are scored using data from an institutional diagnosis of the cases, throughout the research period. Ten out of eleven criteria were positively impacted by the co-management interventions. Three institutional development trajectories can be identified for the fishery co-management building process, involving a range of gradual and abrupt changes. Consolidation of the institutional changes achieved by the interventions is required to successfully develop the resilience of the fishing systems to multiple stresses. This empirical study provides a methodology for systematically assessing institutional dynamics in fisheries, and in particular the crafting and sustaining of co-management regimes in small-scale fisheries. The approach could potentially be applied to other complex social-ecological systems.

Aquaculture Breeding Enhancement: Maturation and Spawning in Sea Cucumbers Using a Recombinant Relaxin-Like Gonad-Stimulating Peptide.

Wild sea cucumber resources have been rapidly exhausted and therefore there is an urgent need to develop approaches that will help restocking. Currently, there is a lack of information regarding the genes involved in sea cucumber reproductive processes. The neurohormone relaxin-like gonad-stimulating peptide (RGP) has been identified as the active gonad-stimulating peptide in sea stars (Asteroidea), which could also be present in other echinoderm groups. In this study, a sea cucumber RGP was identified and confirmed by phylogenetic analysis. A recombinant Holothuria scabra RGP was produced in the yeast Pichia pastoris and confirmed by mass spectrometry. To assess bioactivity, four levels of purification were tested in an in vitro germinal vesicle breakdown (GVBD) bioassay. The most pure form induced 98.56 ± 1.19% GVBD in H. scabra and 89.57 ± 1.19% GVBD in Holothuria leucospilota. Cruder levels of purification still resulted in some GVBD. Upon single injection into female H. scabra, the recombinant RGP induced head waving behavior followed by spawning within 90–170 min. Spawned oocytes were fertilized successfully, larvae settled and developed into juveniles. Our results provide a key finding for the development of a break-through new artificial breeding approach in sea cucumber aquaculture.