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Sea cucumbers are both versatile marine organisms and an Asian marine food known to have several medicinal effects. We evaluated the anti-allergic potential of some major purified holostane-type saponins from the body wall of the black sea cucumber, Holothuria atra. Six saponin compounds were isolated, holothurin B (1), holothurin A (2), 24-dehydro echinoside A (3), desholothurin A1 (4), desholothurin A (5), and des 24-dehydro echinoside A (6). The structures were identified based on spectroscopic methods and by comparison with the literature. Each compound's inhibitory activity toward the release of β-hexosaminidase was evaluated. Among the six compounds, holothurin B (1) showed the strongest inhibition of the degranulation at all tested concentrations in a dose-dependent manner, compared to the positive control, quercetin. We also observed that holothurin B (1) was able to alleviate the inflammatory mediators interleukin (IL)-6, IL-13, and tumor necrosis factor-alpha (TNF-α). Holothurin B (1) also inhibited the Ca2+ influx stimulated by the calcium ionophore A23187, by suppressing the expression of inositol-1,4,5-triphosphate receptor (IP3R) mRNA. These results suggest that (i) holothurin B (1) has good anti-allergy activity without cytotoxicity at effective concentrations, and (ii) this compound could be a lead compound for the treatment of allergic diseases and associated inflammation. We also performed a molecular docking study for the tested compounds to correlate their binding modes and affinity for the IP3R with the in vitro results. The results concluded that the holostane-type saponins could be used as anti-allergy agents, which may be attributed to their holostane group. [ABSTRACT FROM AUTHOR]

Holothurian specimens undergo changes in the thickness of the body wall, in the number of tentacles, and in the presence and absence of some ossicles during their growth. The morphological characterization in different growth stages thus allows a correct identification of species and helps delimiting intraspecific variations. Growth paths can also be an important tool for understanding the evolution of the group. The species Thyonidium seguroensis is distributed in the western Atlantic, from the Gulf of Mexico to the Brazilian coast. A morphological and morphometric analysis was carried out to describe intraspecific variations in different growth stages of T. seguroensis. The analysis showed that the ossicles change their arrangement, shape, and size throughout growth. It was also found that this species has a proportional increase of ossicles with the size of the animal, and that there is a statistically significant difference between the dorsal and ventral ossicles, which may be related to the way of life of these animals in different phases. This type of study helps to clarify the relationships between Thyonidium species, allowing us to understand if there are species complexes or if the morphological variations observed are a result of their ontogenetic development. [ABSTRACT FROM AUTHOR]

Manganese superoxide dismutase (MnSOD) is an antioxidant that exists in mitochondria and can effectively remove superoxide anions in mitochondria. In a dark, high-pressure, and low-temperature deep-sea environment, MnSOD is essential for the survival of sea cucumbers. Six MnSODs were identified from the transcriptomes of deep and shallow-sea sea cucumbers. To explore their environmental adaptation mechanism, we conducted environmental selection pressure analysis through the branching site model of PAML software. We obtained night positive selection sites, and two of them were significant (97F→H, 134K→V): 97F→H located in a highly conservative characteristic sequence, and its polarity change might have a great impact on the function of MnSOD; 134K→V had a change in piezophilic ability, which might help MnSOD adapt to the environment of high hydrostatic pressure in the deepsea. To further study the effect of these two positive selection sites on MnSOD, we predicted the point mutations of F97H and K134V on shallow-sea sea cucumber by using MAESTROweb and PyMOL. Results show that 97F→H, 134K→V might improve MnSOD's efficiency of scavenging superoxide anion and its ability to resist high hydrostatic pressure by moderately reducing its stability. The above results indicated that MnSODs of deep-sea sea cucumber adapted to deep-sea environments through their amino acid changes in polarity, piezophilic behavior, and local stability. This study revealed the correlation between MnSOD and extreme environment, and will help improve our understanding of the organism's adaptation mechanisms in deep sea. [ABSTRACT FROM AUTHOR]

Sea cucumbers are the second most diverse class among echinoderms. They are characterized by an elongated body and dermal ossicles in the body wall. Among the included groups in that class, the order Holothuriida encompasses many species of commercial interest. Faced with the threats of biodiversity loss resulting from the climate crisis and the advancement of cities, this study provides an overview of recent research involving the Holothuriida of the Brazilian Coast. Searches were carried out in the main periodical databases, using appropriate keywords, targeting publications on the subject in the period between 2000 and 2023. In total, 69 publications were found, most of them corresponding to scientific articles in international journals. Most of the studies come from the Northeast region in Brazil (56.52%). Regarding lines of research, those involving taxonomy and molecular analysis were the most prevalent. Over these 20 years, seven species constituted new occurrences. Of note are the studies focused on Holothuria (Halodeima) grisea, which makes up 39.13% of papers. Despite progress, little is known about morphological variations, genetic distance between populations, population densities, and on reproductive biology of species. Brazil has a vast, heterogeneous coastal area, with unique characteristics to which the species are adapted. The findings reinforce the importance to expand studies aiming on knowing the biodiversity, reproductive biology, and population densities of species. Such data are essential for the creation of public policies aimed at the conservation of species of Holothuriida and their habitats. [ABSTRACT FROM AUTHOR]

Parasites exhibit high diversity in various ecosystems. Habitat selection has played an important role in the diversification of parasites by facilitating intra-host speciation and repeated shifts to a single host species by multiple parasite taxa. In this study, we investigated habitat selection in two gastropod species, Melanella cf. acicula and Peasistilifer nitidula (Caenogastropoda: Vanikoroidea: Eulimidae), that are parasitic on the black sea cucumber Holothuria atra in southwestern Japan. The number and position of parasites were observed for 335 hosts; in total, 89 individuals of M. cf. acicula and 194 of P. nitidula were found. Melanella cf. acicula exhibited strong habitat selection, with 70 individuals (78.7%) attached around the host's mouth, whereas P. nitidula had relatively low infection site specificity. This suggests that the two parasite species have different feeding habits. Molecular phylogenetic analysis verified their non-monophyletic relationship, indicating that they likely made independent host shifts to H. atra. The observed difference in habitat preference, as well as the abundance of suitable habitats, may have contributed to the repeated host shifts and sympatric distribution of M. cf. acicula and P. nitidula. Our phylogenetic analysis also revealed the non-monophyly of eulimids parasitising holothuroids, as in asteroid and ophiuroid parasitic taxa. [ABSTRACT FROM AUTHOR]

Sea cucumbers, integral components of benthic ecosystems, have become subjects of scientific scrutiny owing to their intricate morphology and ecological importance. Due to increasing demand, several species of these echinoderms have become overexploited. As a consequence, NE-Atlantic species became new targets for the international markets. There is a vital need for comprehensive biological data to establish and enhance holothurian fisheries management. In the absence of such data, there is a risk of ineffective fisheries regulations, particularly for susceptible commercial species in the NE-Atlantic, which could lead to overexploitation. Establishing effective fisheries regulations requires a foundation of fundamental biological information, such as growth rates from target populations. This work aims to determine the growth parameters for three commercial sea cucumber species from the NE-Atlantic, in a marine protected area, Holothuria mammata, H. forskali and H. arguinensis. This presents a challenge, as sea cucumbers lack significant calcified structures for age determination, and assessing size is complicated because of their body size plasticity. Thus, a von Bertalanffy model was fitted to length-frequency data using the ELEFAN method with the simulated annealing procedure. Underwater length measurements of the three sea cucumber species, in a relaxed state, were systematically recorded over a span of 18 months, with measurements taken every 1.5 months. The results provide the growth parameters of each species. Models considering seasonal growth were better fits to the data. The three species had different growth rates and periods of no growth coincided with the reproductive season. Mortality was lower for the species growing slower. This is crucial information to support decision-making processes regarding stock management, such as setting limits to fisheries considering stock condition associated with environmental variability. [ABSTRACT FROM AUTHOR]

Sea cucumbers (Holothuria scabra), also known as beche-de-mer, are highly valued as a luxurious food item and have been utilized as a traditional tonic food in various Asian countries for centuries. The body walls of sea cucumbers are the main edible part, which are primarily composed of glycosaminoglycan (GAG). The rehydration of dried sea cucumber is a crucial step prior to further processing. The aim of this study was to assess the impact of ultrasound-assisted rehydration (UAR) on the quality of dried sea cucumbers. The experiment used four different rehydration methods, including conventional methods at 27°C (KV27°C) and 15°C (KV15°C), as well as a combination of ultrasound at 27°C with conventional at 15°C (UAR27 + KV15°C) and ultrasound at 15°C with conventional at 15°C (UAR15 + KV15°C). Results indicated that the rehydration rate (RR) was significantly affected by both the rehydration method and the temperature used (p < 0.05). UAR27 + KV15°C was identified as the most effective method in terms of rehydration behavior and quality characteristics of dried sea cucumber, with a RR of 0.58 ± 0.53 gH2O/hour and reduced rehydration time of up to 28 hours. Moreover, the UAR27 + KV15°C method demonstrated superior rehydration potential, nutritional value (proximate composition and sulfate content), color, lower energy, and microstructure properties compared to the other methods. The sulfate content and yield of sulfated GAGs were determined to be 89.4 mg/g and 52.8 μ/g, respectively. Confirmation of the absorption band of the sulfate group showed the presence of 3-N-acetyl galactosamine at a wavelength of 1,269 cm−1 and C-O-S at 860 cm−1. The sea cucumbers treated with UAR exhibited a GAG content approximately 2.9 times higher than those rehydrated with the conventional method. Eventually, the combination of UAR at 27°C with conventional at 15°C methods can significantly accelerate the rehydration of sea cucumber without negatively affecting its physical quality properties.

Sea cucumbers are the second most diverse class among echinoderms. They are characterized by an elongated body and dermal ossicles in the body wall. Among the included groups in that class, the order Holothuriida encompasses many species of commercial interest. Faced with the threats of biodiversity loss resulting from the climate crisis and the advancement of cities, this study provides an overview of recent research involving the Holothuriida of the Brazilian Coast. Searches were carried out in the main periodical databases, using appropriate keywords, targeting publications on the subject in the period between 2000 and 2023. In total, 69 publications were found, most of them corresponding to scientific articles in international journals. Most of the studies come from the Northeast region in Brazil (56.52%). Regarding lines of research, those involving taxonomy and molecular analysis were the most prevalent. Over these 20 years, seven species constituted new occurrences. Of note are the studies focused on Holothuria (Halodeima) grisea, which makes up 39.13% of papers. Despite progress, little is known about morphological variations, genetic distance between populations, population densities, and on reproductive biology of species. Brazil has a vast, heterogeneous coastal area, with unique characteristics to which the species are adapted. The findings reinforce the importance to expand studies aiming on knowing the biodiversity, reproductive biology, and population densities of species. Such data are essential for the creation of public policies aimed at the conservation of species of Holothuriida and their habitats.

Sea cucumbers, integral components of benthic ecosystems, have become subjects of scientific scrutiny owing to their intricate morphology and ecological importance. Due to increasing demand, several species of these echinoderms have become overexploited. As a consequence, NE-Atlantic species became new targets for the international markets. There is a vital need for comprehensive biological data to establish and enhance holothurian fisheries management. In the absence of such data, there is a risk of ineffective fisheries regulations, particularly for susceptible commercial species in the NE-Atlantic, which could lead to overexploitation. Establishing effective fisheries regulations requires a foundation of fundamental biological information, such as growth rates from target populations. This work aims to determine the growth parameters for three commercial sea cucumber species from the NE-Atlantic, in a marine protected area, Holothuria mammata, H. forskali and H. arguinensis. This presents a challenge, as sea cucumbers lack significant calcified structures for age determination, and assessing size is complicated because of their body size plasticity. Thus, a von Bertalanffy model was fitted to length-frequency data using the ELEFAN method with the simulated annealing procedure. Underwater length measurements of the three sea cucumber species, in a relaxed state, were systematically recorded over a span of 18 months, with measurements taken every 1.5 months. The results provide the growth parameters of each species. Models considering seasonal growth were better fits to the data. The three species had different growth rates and periods of no growth coincided with the reproductive season. Mortality was lower for the species growing slower. This is crucial information to support decision-making processes regarding stock management, such as setting limits to fisheries considering stock condition associated with environmental variability.

Benthodytes occidentpalauta sp. nov. was collected from the Kyushu-Palau Ridge at a depth of 5 481 m in 2021. This new species is characterized by a gelatinous body wall, violet skin, six pairs of dorsal papillae, and a rough mid-ventral surface without tube feet. The dorsal deposits are rod-shaped and tripartite. Two types of papillae deposits as crosses with four arms with central bipartite apophyses. Ventral deposits are rods. Tentacle ossicles are rod-shaped with end protrusions. Gonad deposits are rod-shaped, tripartite, and cross-shaped. The phylogenetic analyses based on cytochrome oxidase subunit 1 (COI) and 16S individually and a concatenated dataset of COI and 16S genes of this species support that B. occidentpalauta sp. nov. belongs to Benthodytes. [ABSTRACT FROM AUTHOR]

Benthodytes tetrapapillata sp. nov. was collected from a seamount located on the Caroline Ridge at a depth of 2 289 m, during the cruise of R/V Kexue in June 2019. We provided detailed descriptions of external and deposits morphology. The phylogenetic analyses based on cytochrome c oxidase I (COI) and a concatenated dataset of 16S and COI genes showed that the new species belonged to Benthodytes that is not monophyletic. Both details of morphological comparisons and molecular analyses confirmed that Benthodytes tetrapapillata sp. nov. is a new psychropotid species. A state of main morphological characters in valid species of Benthodytes is also provided in this study. [ABSTRACT FROM AUTHOR]

The ever-growing demand for sea cucumbers is a threat to these echinoderms and their habitats; however, a way to relieve stock pressure lies in meeting demand through aquaculture. As such, this study aimed to improve the growth and survival percentage of Holothuria arguinensis during larval development, settlement and juvenile growth. Three diets of microalgae (Diet RbPt = Rhodomonas baltica + Phaeodactylum tricornutum; Diet RbSm = Rhodomonas baltica + Skeletonema marinoi; Diet RbCc = Rhodomonas baltica + Chaetoceros calcitrans) were administered daily to the larval phase. Additionally, three substrates were supplied (pvc rolls, wavy pvc plaques and tile) at three different depths in order to determine the most favourable for settlement. Lastly, the potential benefits on growth and survival from introducing macroalgae (Sacchoriza polyschides) in the juvenile diet were assessed over a period of 6 months. Despite larvae under diet RbPt having presented a larger mean width, H. arguinensis fed with Diet RbCc presented a higher settlement survival at the end of the trial. No preferences were noted among the tested substrates, regardless of diet. Lastly, juveniles with added S. polyschides in their diet showed increased growth in mean weight and length when compared to individuals that were not fed with this seaweed. [ABSTRACT FROM AUTHOR]

At present, deep-sea enzymes are a research hotspot. In this study, a novel copper–zinc superoxide dismutase (CuZnSOD) was successfully cloned and characterized from a new species of sea cucumber Psychropotes verruciaudatus (PVCuZnSOD). The relative molecular weight of the PVCuZnSOD monomer is 15 kDa. The optimum temperature of PVCuZnSOD is 20 °C, and it maintains high activity in the range of 0–60 °C. It also has high thermal stability when incubated at 37 °C. PVCuZnSOD has a maximum activity of more than 50% in the pH range of 4–11 and a high activity at pH 11. In addition, PVCuZnSOD has strong tolerance to Ni2+, Mg2+, Ba2+, and Ca2+, and it can withstand chemical reagents, such as Tween20, TritonX-100, ethanol, glycerol, isopropanol, DMSO, urea, and GuHCl. PVCuZnSOD also shows great stability to gastrointestinal fluid compared with bovine SOD. These characteristics show that PVCuZnSOD has great application potential in medicine, food, and other products. [ABSTRACT FROM AUTHOR]

Sea cucumbers are of great significance in marine ecosystems all over the world. The red sea cucumber Parastichopus tremulus is also considered commercially interesting but very little information is available on its ecology and physiology. This study aimed at investigating this North Atlantic species` oxygen demand in relation to live-storage period and temperature in an attempt to deliver some physiological puzzle pieces useful in a potential aquacultural context. Oxygen consumption rate (OCR) was measured in P. tremulus stored in a flow-through system for up to one year, and in recirculation systems at different temperatures (4, 8 and 12°C) for up to four weeks. Throughout the experimental period, biometric data were collected from the different treatment groups and a condition index (CI) calculated. The results showed that long-term storage affected OCR and CI, which increased and decreased with time, respectively. Storage at 4°C resulted in significantly lower OCR and higher CI compared to 8 and 12°C after four weeks, suggesting that 4°C may be best for maintaining body mass during short-term storage, whereas storage at 8 and 12°C may require supplementary feeding to avoid biomass loss. Data presented in this study may be useful for a range of applications, for example in a prospective aquaculture setting, for optimizing live seafood storage, but also for impact assessment and management of wild stocks.

Mitochondrial genome (mitogenome) is a frequently-used tool for phylogenetic and evolutionary studies among metazoans, however, it was still poorly represented in some invertebrate groups, including holothurians. Apodida is one of the most ancient orders of Holothuroidea, with unique characteristics in lacking tube feet and the respiratory tree. Here, we sequenced six mitogenomes from the holothurian order Apodida (Synaptidae and Chiridotidae) and compared them with other available holothurian mitogenomes. The apodan mitogenomes present positive GC skews and negative AT skews, a pattern diametrically opposite to that found in the mitogenomes of other holothurians. The amino acid genetic distances of the 13 protein-coding genes (PCGs) were the highest between Apodida and other holothurians. The mitochondrial gene orders within Apodida were extensively rearranged at the species level, and also were unique from the arrangement patterns of other holothurians. Phylogenetic relationships based on two different criteria: (i) nucleotides sequences with all codon positions (PCG123) and (ii) Neutral Transitions Excluded model (NTE) confirmed the monophyly and basal position of the order Apodida with a long branch. The NTE phylogeny generated a low variation of branch length, but it did not ameliorate the long branch length of Apodida. The divergence time estimation suggested that the Apodida originated in the Middle Carboniferous, implying that they survived the extinction event that occurred in the boundary of the Permian and Triassic. The NTE dataset revealed younger age than that generated by PCG123 dataset. Apodida is accompanied by a faster evolutionary rate than other holothurians (0.0069 vs 0.0043 subs/s/my). The absence of tube feet and the respiratory tree may play an important role in the dramatic evolutionary changes of apodan mitogenomes.

The sea cucumber Holothuria arguinensis (Koehler and Vaney, 1906) presents an increasing commercial value in Asian markets and its exportation depends exclusively on wild stock harvesting. Production through aquaculture has been acknowledged as an alternative to supply demand and reduce pressure on natural stocks, but there are still bottlenecks to overcome, such as low growth rate and survival. This study focuses on the evaluation of the growth of juveniles of H. arguinensis through substrate enrichment—direct mixing of Sargassum vulgare with sediment—in recirculating aquaculture systems (RAS), for 4 months, with a baseline diet of Saccorhiza polyschides. Compared to the control (no enrichment), sea cucumbers fed with enriched sediment showed the highest specific growth rate (SGR), the highest growth rate (GR) and the lowest size heterogeneity. The results obtained in this study showed a favorable growth of sea cucumbers when in the presence of a substrate enriched with Sargassum vulgare, representing an important step towards the viability of large-scale sea cucumber rearing in Europe. [ABSTRACT FROM AUTHOR]

Saponin-rich sea cucumber extracts have shown antidiabetic effects in a few reports. Although the triterpene glycosides of sea cucumbers are commonly isolated from their Cuvierian tubules, these are absent in Holothuria atra Jaeger. Therefore, this study intended to investigate the saponin profile in the body wall of H. atra, as well as to assess the α-glucosidase inhibitory activity of the H. atra extracts. The chemical profiling of sea cucumber extracts was conducted by UPLC-HRMS analysis. This resulted in the tentative identification of 11 compounds, 7 of which have not been reported in the H. Atra body wall before. Additionally, two triterpene glycosides were purified and their structures were elucidated based on HRMS and NMR data: desholothurin B (1), and a novel epimer, 12-epi-desholothurin B (2). Moreover, the fatty acid profile of the H. atra body wall was investigated by GC-MS. It was found that the Me90 fraction of the H. atra body wall showed the strongest α-glucosidase inhibitory activity (IC50 value 0.158 ± 0.002 mg/mL), thus making it more potent than acarbose (IC50 value 2.340 ± 0.044 mg/mL). [ABSTRACT FROM AUTHOR]

Sea cucumbers are worm-like, leathery bodied, benthic, marine organisms with a branched gonad. There are over 900 species, and these organisms are capable of changing their mechanical state, regenerating their small appendages, and digestive tract. Additionally, sea cucumbers possess both commercial and therapeutical value. Furthermore, it is thought that the metabolites these organisms possess may give rise to their therapeutical value. The use of sea cucumbers in therapy can be traced back to the Ming dynasty, where they were eaten for their tonic properties against constipation, hypertension, and rheumatism. A plethora of studies have been conducted, whereby different metabolites were extracted from sea cucumbers and tested for different therapeutic properties. Herein, we review and discuss the anti-cancer, anti-microbial, anti-coagulant, anti-diabetic, antioxidant, and anti-inflammatory properties of the sea cucumber by assessing literature on PubMed and Google Scholar. Furthermore, the genome and epigenome of these remarkable species is discussed. With the immense data supporting the therapeutic properties of sea cucumbers, further studies are warranted, in order to develop novel and innovative therapeutic compounds for the benefit of human health from these fascinating marine organisms.

Gastropods from the family Eulimidae have different life strategies in inhabiting their host echinoderms, but it is currently assumed that they derive most of their nutrition from the host's tissues. This paper presents the results of stable carbon and nitrogen isotope analyses of different tissues of echinoderm hosts (crinoids Comaster nobilis and holothurians Holothuria atra) and their ectosymbionts (Annulobalcis wareni and Peasistilifer nitidula). Our data show that the stable nitrogen isotope enrichment level in symbionts is practically indistinguishable from that of their hosts. The symbionts are depleted in 13C compared to their hosts. We suggest that these molluscs may not feed on host tissues but instead obtain food particles from the environment, possibly stealing detritus particles, which, in turn, are food for these species of echinoderms. We revealed the proximity of the location and slight overlap of the crinoids' visceral tissue and their symbiont tissues. This suggests a greater food variety for the symbionts. The detected differences in δ13C values and the almost complete absence of overlap of the holothurians' body walls and symbionts allow us to conclude that in this symbiotic association, the hosts and symbionts rely on different food sources. In addition, the two studied echinoderm species differed significantly in δ13C signatures, which is confirmed by their different lifestyles. Thus, stable isotope analysis suggests that kleptoparasitism is at least an additional and possibly exclusive feeding mode for eulimids A. wareni and P. nitidula. However, this hypothesis will need to be followed up with morphological, biochemical, and experimental data. [ABSTRACT FROM AUTHOR]

T. Sea cucumbers (holothuroids) play a major role in coastal environments; their detritivore conduct favors oxygen penetration in the sediments and the disposal of pathogens on the sea floor. This study determined holothuroid diversity in the rocky intertidal zone of Matanchén Bay, Mexico. Sampling campaigns were carried out in January, March, May, and July 2018. Linear transects (10 m length and 1 m width) perpendicular to the coastline in rocky areas (0-3 m depth) were established, where the density (ind m-2 ) and proportion (%) of sea cucumbers were estimated. Organisms were photographed, examined live, and preserved in 70% alcohol for subsequent identification utilizing ossicle characterization. Our results show the presence of four sea cucumber species: Holothuria (Halodeima) inornata Semper, 1868, Holothuria (Selenkothuria) lubrica Selenka, 1867, Holothuria (Selenkothuria) portovallartensis Caso, 1954, and Holothuria (Mertensiothuria) viridiaurantia Borrero-Pérez & Vanegas-González, 2019. The average density per species was 0.208, 0.108, 0.017, and 0.025 ind m-2, respectively; each species' proportion was 58.1, 30.2, 4.7, and 7.0%, respectively. Due to the above values, we found that the number and spatial distribution of sea cucumber species vary in Matanchén Bay. [ABSTRACT FROM AUTHOR]

Echinodermata pada dasarnya merupakan indikator kesehatan dan status dari terumbu karang di laut. Dasar perairan yang landai dengan substrat pasir, terumbu karang, dan pecahan karang merupakan habitat bagi hewan jenis Asteroidea, Echinoidea, dan Teripang. Penelitian ini bertujuan untuk mengidentifikasi jenis-jenis bintang laut (Asteroidea), bulu babi (Echinoidea), dan teripang (Holothuroidea) dari perairan Pulau Tunda, Kabupaten Serang. Pengamatan Asteroidea, Echinoidea, dan Holothuroidea menggunakan metode line transek yang dimodifikasi, yaitu mengamati subjek dalam jarak yang sama sepanjang garis transek dan kuadrat transek dengan pengamatan 2,5 m di sebelah kanan dan kiri garis line transek. Observasi habitat yang meliputi substrat dan kedalaman, sedangkan jumlah total bintang laut, bulu babi, dan teripang di setiap stasiun dicatat yang selanjutnya sampel didokumentasikan dan diidentifikasi berdasarkan ciri-ciri morfologinya. Di perairan Pulau Tunda ditemukan 2 spesies dari kelas Asteroidea yaitu Linckia laevigata dan Culcita novaeguneae, 3 spesies dari Echinoidea yaitu Diadema antilarum, Diadema setosum, Echinomerta mathaei, dan 3 spesies dari Holothuroidea yaitu Holothuria atra, Holothuria leucospilota, Bohadschia graeffei.

For the first time, this study analyses the composition and diversity of the gut microbiota of Isostichopus badionotus in captivity, using high-throughput 16S rRNA sequencing, and predicts the metagenomic functions of the microbiota. The results revealed a different composition of the gut microbiota for the foregut (FG) and midgut (MG) compared to the hindgut (HG), with a predominance of Proteobacteria, followed by Actinobacteria, Bacteroidetes, and Firmicutes. The FG and MG demonstrated a greater bacterial diversity compared to the HG. In addition, a complex network of interactions was observed at the genus level and identified some strains with probiotic and bioremediation potentials, such as Acinetobacter, Ruegeria, Streptococcus, Lactobacillus, Pseudomonas, Enterobacter, Aeromonas, Rhodopseudomonas, Agarivorans, Bacillus, Enterococcus, Micrococcus, Bifidobacterium, and Shewanella. Predicting metabolic pathways revealed that the bacterial composition in each section of the intestine participates in different physiological processes such as metabolism, genetic and environmental information processing, organismal systems, and cellular processes. Understanding and manipulating microbe––host–environment interactions and their associated functional capacity could substantially contribute to achieving more sustainable aquaculture systems for I. badionotus. [ABSTRACT FROM AUTHOR]

The Ordovician Period witnessed the first evidence of appearance of all modern echinoderm clades as well as it is the most concentrated interval of echinoderm diversity in Earthâs history. This knowledge is largely based on reports from Baltica, Avalonia, Laurentia and Gondwana. However, the Ordovician record of sea cucumbers (Holothuroidea) and their allies, like echinoids and ophiocistioids (Echinozoa), is sparse and patchy. The earlier published Cambrian or Ediacaran records of echinozoan echinoderms (e.g., sea cucumbers) are based on misinterpreted specimens of other phyla. Neither the origins of the Echinozoa nor the split of holothuroids from ophiocistioids or echinoids are properly understood. One reason for this is the fact that less than 100 (articulated) Ordovician specimens of sea urchins, sea cucumbers and ophiocistioids have been recovered worldwide so far. In general, fossil remains of the Holothuroidea are limited to (1) innumerable microscopic and/or mesoscopic ossicles of the body wall, (2) five distinct calcareous plates which supported the anus in some (more highly evolved) sea cucumber groups, and (3) a total of usually ten radial and interradial elements of the calcareous ring surrounding the pharynx. The latter represents a synapomorphy for the entire group and is important in the higher-level group systematics. In addition, to date, there are only about two dozen known Phanerozoic localities (Konservat-Lagerstätten and obrution deposits) that have yielded (4) articulated body fossils of holothurians. Few attempts have been made to use disarticulated fossils of Echinodermata to understand the distribution, diversity and early radiation of Holothuroidea, Echinoidea and Ophiocistioidea. Only during the last two decades, advanced micropalaeontological and macropalaeontological techniques have been combined to investigate these understudied echinoderm groups in greater detail. This will help to gain further understanding about the Early Palaeozoic echinozoan echinoderms. In this presentation, a short overview of known holothurian finds (mostly from Baltica) is given.

At present, deep-sea enzymes are a research hotspot. In this study, a novel copper–zinc superoxide dismutase (CuZnSOD) was successfully cloned and characterized from a new species of sea cucumber Psychropotes verruciaudatus (PVCuZnSOD). The relative molecular weight of the PVCuZnSOD monomer is 15 kDa. The optimum temperature of PVCuZnSOD is 20 °C, and it maintains high activity in the range of 0–60 °C. It also has high thermal stability when incubated at 37 °C. PVCuZnSOD has a maximum activity of more than 50% in the pH range of 4–11 and a high activity at pH 11. In addition, PVCuZnSOD has strong tolerance to Ni2+, Mg2+, Ba2+, and Ca2+, and it can withstand chemical reagents, such as Tween20, TritonX-100, ethanol, glycerol, isopropanol, DMSO, urea, and GuHCl. PVCuZnSOD also shows great stability to gastrointestinal fluid compared with bovine SOD. These characteristics show that PVCuZnSOD has great application potential in medicine, food, and other products.

Simple Summary: Mitochondrial genomes are a type of specific genetic marker, characterized in most animals by a rapid mutation rate, high copy numbers and the absence of genetic recombination. They are widely applied in phylogenetics, population genetics and ecological research. Bohadschia argus is a sea cucumber with high economic value. Currently, the mitochondrial genomic data of B. argus are not available. In this study, next-generation sequencing was performed on the mitochondrial genome of B. argus. The gene arrangement order in the mitochondrial genome of B. argus was consistent with the echinoderm ground pattern. Finally, phylogenetic analysis using the 13 protein-coding genes of mitochondria confirmed the phylogenetic position of B. argus. Bohadschia argu is a kind of sea cucumber with high economic value; it is the only undisputed species in the genus Bohadschia. In this study, the complete mitochondrial genome (mitogenome) of B. argus was acquired through high-throughput sequencing. The mitochondrial genome of B. argus was 15,656 bp in total length and contained a putative control region (CR) and 37 typical genes of animal mitochondrial genomes, including 13 protein-coding genes (PCGs), 2 ribosomal RNA genes (rrnS and rrnL) and 22 transfer RNA genes (tRNA). The sizes of the PCGs ranged from 168 bp to 1833 bp, and all PCGs except nad6 were encoded on the heavy chain (H). Both rrnS and rrnL were also encoded on the H chain. Twenty-two tRNA genes had positive AT skew and GC skew. All tRNAs had a typical cloverleaf secondary structure except for trnI, in which an arm of dihydrouridine was missing. B. argus shared the same gene arrangement order (the echinoderm ground pattern) as other species in Aspidochirotida. Phylogenetic analysis clearly revealed that B. argus belongs as a member of the Holothuriidae, and it is closely related to members of Actinopyga and Holothuria. [ABSTRACT FROM AUTHOR]

Wild juvenile collection (WJC) from settling larvae has been reported for two temperate holothurians (Apostichopus japonicus and Apostichopus californicus), mainly for the objective of restocking, but its applicability to tropical holothurians is unknown. This study, for the first time, tested the applicability of WJC for tropical sea cucumbers.First, hatchery‐produced larvae of peanutfish (Stichopus horrens) before settlement were introduced in a tank in which bundles of coconut fibre, rolled mesh bags, and oyster shells were suspended to identify the most suitable settlement material. The results showed that the coconut fibre and mesh bags collected more settling larvae than the oyster shells.Second, 25 collectors were installed for 3 months in the field in Nggela, Solomon Islands. The newly designed simple collector comprised between two and four net bags filled with coconut fibre, which were tied to a rope vertically moored between a concrete block anchor and polyethylene terephthalate (PET) bottle floats. A total of 14 juvenile holothurians were collected, including Stichopus cf. horrens, stonefish (Actinopyga lecanora), kingfish (Synapta maculata), and five unidentified species. It is characteristic of tropical WJC that diverse species can be collected simultaneously (including rare, non‐culturable species), which is advantageous over hatchery production for restocking purposes. The total yield corresponded to approximately 1% of the total abundance of the ambient holothurian community, demonstrating potential for restocking, considering the ease of the extension and repetition of the trials. Collection in the inner bay areas was successful, whereas rough weather physically damaged the collectors in areas open to the ocean.These results show that WJC is a viable option for tropical holothurians. Thus, the use of the low‐cost, simple collectors using coconut fibre could be a new conservation measure for endangered holothurian resources, and are manageable by local communities. [ABSTRACT FROM AUTHOR]

• Echinoderms possess the ability to voluntarily stiffen or soften their collagenous tissues through the release of specialized effector proteins. • Using a combination of in silico analyses, Hf-(D)Tensilin, a stiffening protein from the dermis of the sea cucumber Holothuria forskali, was identified. • Specific antibodies revealed that this protein is localized in the secretory granules of type 2 juxtaligamental-like cells, a mutable collagenous tissue specific cell type. • Recombinant tensilin stiffens pieces of dermis and aggregates collagen fibrils in vitro. • Assays with truncated recombinant proteins and with various compounds disentangled the molecular interactions which mediate tensilin aggregating effect on collagen fibrils. • Understanding the molecular mechanism underlying sea cucumber dermis mutability is a prerequisite for the development of biomimetic smart dynamic materials. Mutable collagenous tissues (MCTs) from echinoderms (e.g., sea stars, sea urchins) possess the remarkable ability to change their mechanical properties rapidly and reversibly thanks to the release of effector molecules regulating the number of cross-links between collagen fibrils. Among these effector molecules, tensilin has been identified as a stiffening factor in sea cucumber MCTs. Since its discovery and description twenty years ago, tensilin orthologs have been identified in a few sea cucumber species but no novel information about its molecular mode of action has been reported. In this study, using a combination of in silico analyses, we identified the tensilin present in the dermis of Holothuria forskali , Hf-(D)Tensilin. Anti-peptide antibodies showed that this protein is localised in the secretory granules of type 2 juxtaligamental-like cells, a MCT specific cell type. We then used the bacterium E. coli to produce recombinantly Hf-(D)Tensilin and confirmed its stiffening effect on pieces of the dermis and its aggregation effect on collagen fibrils extracted from the sea cucumber dermis. To investigate how tensilin can cross-bridge collagen fibrils, truncated recombinant tensilins were also produced and used in combination with various compounds. Results suggest that two types of interactions contribute to the aggregation effect of tensilin on the fibrils: (1) the N-terminal NTR TIMP like domain of the protein interacts strongly with sulfated GAGs attached to the surface of the collagen fibrils, and (2) the C-terminal part of the protein is involved in its dimerisation/oligomerisation through ionic but possibly also cation-π and hydrophobic interactions. [ABSTRACT FROM AUTHOR]

Holothuria scabra is one of the most intensively studied holothuroids, or sea cucumbers (Echinodermata: Holothuroidea), having been discussed in the literature since the early 19th century. The species is important for several reasons: (1) it is widely distributed and historically abundant in several shallow soft-bottom habitats throughout the Indo-Pacific, (2) it has a high commercial value on the Asian markets, where it is mainly sold as a dried product (beche-de-mer) and (3) it is the only tropical holothuroid species that can currently be mass-produced in hatcheries. Over 20 years have elapsed since the last comprehensive review on H. scabra published in 2001. Research on H. scabra has continued to accumulate, fuelled by intense commercial exploitation, and further declines in wild stocks over the entire distribution range. This review compiles data from over 950 publications pertaining to the biology, ecology, physiology, biochemical composition, aquaculture, fishery, processing and trade of H. scabra, presenting the most complete synthesis to date, including scientific papers and material published by local institutions and/or in foreign languages. The main goal of this project was to summarize and critically discuss the abundant literature on this species, making it more readily accessible to all stakeholders aiming to conduct fundamental and applied research on H. scabra, or wishing to develop aquaculture, stock enhancement and management programs across its geographic range. [ABSTRACT FROM AUTHOR]

The interstitial environment of sandy bottoms is an enigmatic habitat that forms unique ecosystems containing significant numbers of biodiversity. One of the lesser known marine invertebrate that inhabit this environment are sea cucumbers. The relative scarcity and lack of attention paid on these species have been the main obstacles to research and hence, knowledge of their taxonomy, biology, and ecology is limited. Thus, this review attempts to summarize the up-to-date overview of available knowledge on the diversity, distribution and the biology of interstitial sea cucumbers. [ABSTRACT FROM AUTHOR]

Among the specific characters of holothurians, the main ones are: the structure of the ambulacral (water vascular) system, the presence of oral (buccal) tentacles, the calcareous ring, and bilateral symmetry of the larval and definitive stages of development. In all modern Eleutherozoa, except Holothuroidea, the five primary outgrowths of the hydrocoel first develop as tentacles and then transform into radial ambulacral canals. In holothurians, five primary outgrowths of the hydrocoel give rise to five primary tentacles arranged around the oral opening, and the radial ambulacral canals develop on the hydrocoel between them later and end aborally. I propose that Echinodermata descended from ancestors which, like modern Pterobranchia, had tentacles, with coeloms which were derived from the mesocoel. I previously proposed a hypothesis of a two-stage development of the ambulacral system of Eleutherozoa. The first stage is the development of tentacle-shaped outgrowths of the hydrocoel. Then there is a switch to the next stage, i.e., the development of the ambulacral canals incorporated in Eleutherozoa into the body wall. I suggest that the ancestors of holothurians switched to locomotion on the ventral side of the settled larva, as is observed in modern holothurians, and fed using the primary tentacles. Obviously, since the primary tentacles of holothurians remained as tentacles, they could not have been transformed into ambulacral canals. As a result, the ontogeny of holothurians changed. It is logical to assume that these changes in the structure of the ambulacral system of holothurians were associated with changes in the mechanisms for realization the program of transformation of primary tentacles into ambulacral canals. It is possible that the mechanism of regulation of the development of the ambulacral system of holothurians occurred by splitting the initial program and / or duplication of its initial stages. Radial ambulacral canals began to develop later between the primary tentacles. Changes have also taken place in the development of other organ complexes. Some of them, as a result of equifinality of development, have a structure similar to homologous organs in Echinoidea. Other organ systems: the skeleton, the reproductive system and, possibly, the axial complex developed through paedomorphosis. As a result of these processes, the morphogenetic holothurian archetype was formed. It is probable that the segments of the calcareous ring of Holothuroidea are modified first ambulacral plates and are homologous to some parts of the oral apparatus of other Eleutherozoa. It is less likely, though hypothetically possible, that the radial segments of the calcareous ring of holothurians are homologous to the terminal plates of Eleutherozoa. Bilateral symmetry in holothurians is not a novelty but arose on the basis of the initial bilateral symmetry of the echinoderm ancestor. The pentaradial symmetry developed in the course of evolution did not disappear, but was coordinated with bilateral symmetry, and the symmetry of holothurians can be characterized as pentaradial-bilateral-asymmetrical. [ABSTRACT FROM AUTHOR]

In this study, we sequenced the circular mitochondrial genome (mitogenome) of Cercodemas anceps. This genome was determined to measure 16,539 bp in length and contain 13 protein-coding genes (PCGs), 22 tRNA genes, and 2 rRNA genes. The longest gene was observed to be nad5, which measures 1,641 bp in length and is located at position 6,540 ∼ 8,180 of the C. anceps mitogenome. One PCG, nad6, and five tRNA genes (tRNASer(UCN), tRNAGln, tRNAAla, tRNAVal, and tRNAAsp) were located on the light chain, and the other genes were located on the heavy chain. A phylogenetic tree was constructed with the mitogenome sequences of 26 types of echinoderm species, and the results show that C. anceps is most closely related to C. quadrangularis.

There is an increasing demand for sea cucumbers, for human consumption, mainly from Asian markets and, as a consequence, NE-Atlantic species are now new targets for exploitation and exportation. Holothuria mammata is one of the most valuable species in Europe. However, the lack of historical economic interest in this species in most European countries has also led to a lack of studies concerning biological and ecological aspects on wild populations and this is a major issue for stock management. This study aims to determine the temporal and spatial patterns of distribution of H. mammata, considering its abundance and demographic structure in a NE-Atlantic area, SW Portugal, as a function of environmental conditions. For that, a population from a marine protected area was followed for 1 year at 1.5-month intervals. Throughout the coastal area, six sites were selected and at each sampling campaign three random transects per site and substrate (rock and sand) in which all H. mammata individuals were counted and measured. For each site and survey several environmental parameters of interest, from the water column, the sediment and substrate cover, were also measured. Generalized Linear Models were used to model the spatial and temporal distribution of the species according to environmental conditions, to determine the species’ habitat preferences. The distribution models indicate that abiotic and biotic parameters of the water column are not the main drivers shaping the distribution of H. mammata. The species has a patchy distribution, and its habitat preferences depend on environmental stability, the presence of shelter and habitat complexity, which is more important for smaller, more vulnerable, individuals, while bigger size classes tend to venture more into less stable environments in an opportunistic fashion. The knowledge of these population traits is determinant to develop stock management measures, which are now urgent to prevent the depletion of commercial sea cucumber populations in the NE-Atlantic. Sustainable fisheries policies should be developed and start by considering to delimit fishing areas and periods, considering the species spatial and temporal distribution patterns.

Structural diversity of triterpene glycosides produced by sea cucumbers or holothurians (Holothuroidea, Echinodermata) is extremely high, although all of them are either lanostane derivatives or, rarely, products of their molecular rearrangements. The majority of them are holostane derivatives possessing an 18(20)-lanostane lactone as aglycone. They contain carbohydrate chains consisting of one to six monosaccharide units including sulfated ones. The glycosides demonstrate interesting biological activities, mainly caused by membranolytic action, namely cytotoxic, ichthyotoxic, antifungal, and hemolytic properties, as well as a series of additional effects at sub-toxic doses, including immunomodulatory, and cancer preventive. This review summarizes the literature data concerning structures and biological activities of all the new triterpene glycosides isolated from sea cucumbers during 2017 to 2021. [ABSTRACT FROM AUTHOR]

Sea cucumbers' historical demand, together with the depletion of several traditional species in the market, has popularized new target species from new fishing grounds. Holothuria forskali is one of those emergent species in the trade market. However, it is a species for which there is no relevant information to allow sustainable stock management. Fundamental knowledge of the populations' structure and habitat preferences are key elements without which any measure is inconsequent. This work aims to fill that gap by modelling temporal and spatial patterns of abundance and demographic structure of this species in a NE-Atlantic area, as a function of environmental features. For a period of 15 months, nine regular sampling campaigns collected data on density, individual length, individual conditions of occurrence (e.g. sheltered, on sand, on algae cover) and environmental parameters (water column, sediment, substrate cover and type), using random transects throughout a costal rocky-reef, considering habitat heterogeneity and substrate types. To determine the species' habitat preferences Generalized Linear Models were used to model density and demographic structure of the species as a function of environmental conditions. The models revealed that the main drivers shaping the distribution of H. forskali are neither abiotic nor biotic parameters of the water column, but physical stressors, like current intensity and depth, and substrate type in a patchy distribution pattern. Estuarine conditions are generally avoided, although with a size-dependent opportunistic strategy. Larger individuals show temporal and spatial displacement patterns towards suitable reproductive conditions (pre-breeding aggregation) and favourable feeding grounds and smaller size-classes tend to aggregate in higher numbers in more stable environments. Sustainable sources for market supply, like aquaculture, are still a long way from commercial production. So, these results are fundamental to support effective conservation measures for stock management of H. forskali. • The habitat preferences of H. forskali are mainly driven by physical stressors. • Juveniles aggregate in higher numbers in more stable environments. • H. forskali shows a patchy distribution and a reproductive aggregation behaviour. • H. forskali displays a feeding size-dependent opportunistic strategy. [ABSTRACT FROM AUTHOR]

Abstract Background For echinoderms with feeding larvae, metamorphic and post-settlement success may be highly dependent on larval nutrition and the accumulation of energetic lipids from the diet. In contrast to the sea urchins, starfish and brittle stars within the Phylum Echinodermata, sea cucumber metamorphosis does not involve formation of a juvenile rudiment, but instead there is a rearrangement of the entire larval body. Successful metamorphosis in sea cucumbers is often associated with the presence in the late auricularia stage of an evolutionary novelty, the hyaline spheres (HS), which form in the base of the larval arms. Known since the 1850s the function of these HS has remained enigmatic—suggestions include assistance with flotation, as an organizer for ciliary band formation during metamorphosis and as a nutrient store for metamorphosis. Results Here using multiple methodologies (lipid mapping, resin-section light microscopy, lipid and fatty acid analyses) we show definitively that the HS are used to store neutral lipids that fuel the process of metamorphosis in Australostichopus mollis. Neutral lipids derived from the phytoplankton diet are transported by secondary mesenchyme cells (“lipid transporting cells”, LTC), likely as free fatty acids or lipoproteins, from the walls of the stomach and intestine through the blastocoel to the HS; here, they are converted to triacylglycerol with a higher saturated fatty acid content. During metamorphosis the HS decreased in size as the triacylglycerol was consumed and LTC again transported neutral lipids within the blastocoel. Conclusion The HS in A. mollis functions as a nutrient storage structure that separates lipid stores from the major morphogenic events that occur during the metamorphic transition from auricularia–doliolaria–pentactula (settled juvenile). The discovery of LTC within the blastocoel of sea cucumbers has implications for other invertebrate larvae with a gel-filled blastocoel and for our understanding of lipid use during metamorphosis in marine invertebrates.

Despite descending from heavily calcified ancestors, the holothuroid skeleton is fully internal and composed of microscopic ossicles and a ring of plates bound by connective tissue, the calcareous ring. The calcareous ring exhibits a complex and poorly understood morphology; as a result, establishing unambiguous homology statements about its macrostructure has been challenging and phylogenetic studies have had to simplify this important structure. Here, we provide the first broad comparative study of Dendrochirotida calcareous rings using micro‐computed tomography (μCT). A detailed description of the three‐dimensional macrostructure of the calcareous ring of 10 sea cucumber species, including rare and type specimens, is presented. The structures observed were highly variable at the subfamily level, especially at the point of tissue attachment. The relationship between the calcareous ring and its associated organs, and their functional morphology are discussed. To aid future phylogenetic studies, we listed 22 characters and performed a preliminary cladistic analysis. The topology obtained supports the idea that the simple, cucumariid ring is ancestral to the mosaic‐like phyllophorid ring; however, it did not support the monophyly of the cucumariids. It also did not support the family Sclerodactylidae, which was described based on the ring morphology. Differently from the dermal ossicles, which are highly homoplastic, the general homoplasy index of the calcareous ring characters was relatively low. This result highlights the importance of this structure for phylogenetic inference. Unfortunately, time since collection, rough collection methods and fixation can damage the skeleton, and the calcareous ring is often overlooked in taxonomic descriptions. The data presented here will improve our understanding of holothuroid relationships and facilitate studies on holothuroid functional morphology and biomechanics. [ABSTRACT FROM AUTHOR]

The main goal of this study was to investigate the seasonal chemical changes of two sea cucumber species caught from Portugal. The potential contribution to human health of lipids was also evaluated. For this, the chemical composition (protein, ash, and fat) and lipids composition of Holothuria arguinensis and Holothuria forskali was followed in summer and winter. Both species presented adequate levels of protein and ash and low content of total lipids, although their lipid profile showed a high proportion of polyunsaturated fatty acid (PUFA). Eicosapentaenoic acid (EPA) was abundant in all samples, and a favorable and similar n-3/n-6 ratio was found for both species. The atherogenic and thrombogenicity indices and hypocholesterolaemic/hypercholesterolaemic ratio suggests a high-quality for H. arguinensis and H. forskali. In general, significant differences were observed between species but not between summer and winter. Some significant variations were observed between summer and winter in the lipid profile of both species and in the chemical composition of H. forskali. Results indicate that these species have adequate nutritional quality for human consumption and may be suitable for the development of reliable fatty acid guides in sea cucumbers. [ABSTRACT FROM AUTHOR]

Thyonella gemmata , also known as the Green sea cucumber, is a biomedically and ecologically important species. In this study, the complete mitogenome of T. gemmata (Echinodermata: Holothuroidea) collected from the Florida Panhandle, USA is reported. The mitochondrial genome of T. gemmata consisted of 15,696 base pairs, and was composed of 36.10% A, 28.27% T, 23.18% C, and 12.45% G. There were 13 protein coding genes, 22 tRNA genes, and 2 rRNA genes within the mitogenome of T. gemmata. Mapping out the complete mitochondrial genome of T. gemmata, will help aid in future evolutionary studies and can be applied to future phylogenetic research of holothurians and related species.

The aim of this study was to determine the concentration of proAKAP4 and other indicators of cryopotential of spermatozoa cryopreserved in extender with Holothuroidea extract addition. Nine Holstein Friesian bulls, 3.5 years old, of known health status, were used for the study. The animals were kept and fed equally. Semen was collected once a week using an artificial vagina. The commercially available Holothuroidea extract was used as a supplement to the commercial extender (0, 2, 4 and 6 µL/mL) before the freezing/thawing process. The viability, motility, motion parameters, and acrosome integrity of the sperm were analyzed with (test) or without (control) extract samples. Furthermore, the concentration of the proAKAP4 biomarker in frozen sperm was assessed. It was shown that the addition of 4 and 6 µL of the extract may have a positive effect on the quality parameters of the sperm after thawing. The results indicate that extender supplementation with the above extract modulates (increases) the concentration of proAKAP4 in sperm at all tested levels. Additionally, this indicator has become helpful in identifying sperm of poor biological quality. Moreover, it has been proven that the proAKAP4 biomarker can be successfully used to evaluate the effectiveness of the use of various extenders for semen cryopreservation.

Introduction: The genus Leptopentacta has only been previously reported from Florida, Cuba, Colombia, Costa Rica, and Suriname. Objective: To present the first record of the genus for Nicaragua. Methods: The morphological characters of Nicaraguan material at the Smithsonian Institution (USNM 1014529), were corroborated with the original description. Results: The five specimens collected in the Nicaraguan Caribbean match the genus. Conclusions: Leptopentacta is reported for the first time from the Nicaraguan Caribbean Sea. This increases the number of Nicaraguan echinoderms to 194 species. [ABSTRACT FROM AUTHOR]

A new species of dendrochirotid holothurian, Cucumaria fedotovi sp. nov. (Holothuroidea, Dendrochirotida, Cucumariidae), has been described in the Karaginskii Gulf, Bering Sea, Russia, from the depths of 31–34 m. The new species differs from the other species of the genus Cucumaria by the shape of ossicles of the body skin and by tube feets. The new species is characterized by ossicles in form of large lobed perforated plates with sharp teeth on the outer edge. In the tube feets, large, specific, laciniate, stellate plates predominate (up to ten rays), with numerous holes and sharp teeth along the outer edge. [ABSTRACT FROM AUTHOR]

The Polynoidae, commonly known as "scale-worms" due to the scale-like elytra on the dorsal surface, contains many species living in symbioses with other invertebrates. Most of these symbionts are host-specific, but some have a wide range of hosts. The genus Asterophilia includes two species living in shallow subtropical to tropical waters in the Pacific Ocean as ectosymbionts of asteroids and, more rarely, crinoids. Here, we recorded Asterophilia culcitae from asteroid hosts (Culcita novaeguineae, Linckia laevigata, L. guildingi, and Leiaster leachi) and, for the first time, from holothurian hosts [Stichopus chloronotus, Holothuria atra, H. (Stauropora) pervicax, and Bohadschia argus] along warm Japanese Pacific coasts. The cytochrome c oxidase subunit I sequences of the specimens from holothurians did not differ significantly from those on asteroid hosts, proving that A. culcitae has a wide host range across three different echinoderm classes: asteroids, holothurians, and crinoids. The general body color of A. culcitae was constantly reddish (female) or whitish (male), regardless of the host body color, although a previous study suggested that it differs in accordance with the host body color. However, we found that one individual from a holothurian host showed a different color pattern: A. culcitae typically shows three whitish or yellowish elytral mounds that have been suggested to mimic the tube foot of the asteroid hosts, whereas one individual from S. chloronotus had reddish brown translucent mounds, which we suggest might be cryptic on its holothurian host. [ABSTRACT FROM AUTHOR]

Bromlichnus bromleyi n.igen. n.isp., a compound trace fossil consisting of two segments representing dwelling and feeding, is described. Owing to a concentric spreite in a bow-shaped burrow, B. bromleyi is interpreted as made by holothurians. In most cases, it is connected to a repichnion. The new ichnotaxon derives from the narrow Pfalzpaint Subbasin of the Solnhofen archipelago (Upper Jurassic, SE Germany), interpreted as a tidal channel connecting two basins. The interrelationships of different behaviours reflected in compound trace fossils allow holistic analysis of the work of individual animals, enabling more accurate interpretation of tracemaker anatomy and function. [ABSTRACT FROM AUTHOR]

This study established the DNA barcodes of 19 economically important Philippine sea cucumbers belonging to Class Holothuroidea under Phylum Echinodermata using the cytochrome c oxidase I (COI) gene. These include sea cucumbers from the Family Holothuriidae under Order Aspidochirotida: Bohadschia marmorata, B. koellikeri, B. vitiensis, B. argus, Bohadschia sp. 1, Actinopyga echinites, A. lecanora, Holothuria scabra, H. fuscogilva, H. atra, H. impatiens, and H. albiventer; from the Family Stichopodiidae under Order Aspidochirotida: Stichopus horrens, S. monotuberculatus, S. vastus, S. hermanni, S. chloronotus, and Thelenota ananas; and from the Family Phyllophoriidae under Order Dendochirotida was Neocucumis proteus. Based on Kimura-2 pairwise (K2P) distances, low genetic variation within species of 0.005-0.018 was observed except for several species such as S. chloronotus, H. albiventer, A. echinites, and H. scabra - which had 0.057, 0.181, 0.207, and 0.215 within-species genetic variations, respectively. On the other hand, variation between species within a genus was 0.123 for Bohadschia, 0.18 for Actinopyga, 0.19 for Holothuria, and 0.071 for Stichopus. Phylogenetic tree using neighbor-joining analysis showed monophyletic clades for the genera Bohadschia, Actinopyga, Stichopus, Thelenota, and Neocucumis while paraphyletic clade was formed for the genus Holothuria. COI DNA sequences and barcodes were established for the first time for Neocucumis proteus and Holothuria albiventer. [ABSTRACT FROM AUTHOR]