Holothuria

About: Holothuria is a research topic. Over the lifetime, 362 publications have been published within this topic receiving 4982 citations.

CYTOTOXIC SATURATED FATTY ACIDS FROM THE INDONESIAN SEA CUCUMBER Holothuria sp.

Abstract: Sea cucumbers are one of Indonesia’s marine organism with the potential to be developed as possible herbal medicines. In a preliminary study of cytotoxic activity of ethanol extracts of 14Indonesian sea cucumber species, the most active extract came from the Holothuria sp. Thecurrent research aimed to identify the major cytotoxic component in the sea cucumber Holothuriasp., that yielded the most active extract. The samples were collected from South Lampung beach.Isolation of the cytotoxic component was done employing liquid flash and preparative reversedphase (C 18) chromatography. Cytotoxic ity evalu atio n of fractio ns collected durin g thechromatography was conducted using the MCF-7 tumor cell line. Elucidation of the structure ofmost active isolate was done by NMR (Nuclear Magnetic Resonance) spectroscopy and GC-FID(Gas-Chromatography-Flame Ionisation Detector) analysis. The results of these analyses showedthe most active compound to be stearic acid; IC 50towards MCF-7 cells 10.32 ppm.

New records of sea cucumbers (Echinodermata: Holothuroidea) at Islas Marietas, Central Mexican Pacific

Abstract: Sea cucumbers (phylum Echinodermata) are common members of benthic communities in many marine ecosystems. They function as nutrient recyclers and bioturbators of soft bottoms, and are preyed upon by birds, fishes, mollusks, crustaceans and other taxa. In the Central Mexican Pacific, Islas Marietas harbours a complex and diverse community of corals and benthic invertebrates, with a particularly well-represented assemblage of echinoderms. However, little is known about the diversity of holothurians in the area. Between 2012 and 2014 a bimonthly census was conducted at Islas Marietas, and seven species were recorded for the first time at this location: Holothuria (Halodeima) inornata, Holothuria (Mertensiothuria) hilla, Holothuria (Platyperona) difficilis, Neocucumis veleronis, Lissothuria ornata, Afrocucumis ovulum and Pachythyone pseudolugubris. The absence of previous records of these species may be associated with their low densities and cryptic habits. This report acts to fill a critical knowledge gap in the distribution of holothurians in the eastern tropical Pacific and highlights the under-appreciated biodiversity of this Natural Protected Area.

The sea cucumber Holothurialineata Ludwig, 1875 (Holothuroidea, Aspidochirotida, Holothuriidae) re-described from the newly found type.

Abstract: A re-description of the little-known holothurian species Holothuria (Lessonothuria) lineata Ludwig, 1875 is given. It is based on the single recovered type specimen and an individual recently collected on Glorioso Islands, near Madagascar. A key to separate three closely related and commonly confused species, i.e., Holothuria (Lessonothuria) pardalis Selenka, 1867, Holothuria (Lessenothuria) verrucosa Selenka, 1867 and Holothuria (Lessonothuria) insignis Ludwig, 1875, is presented.

Predator Defense Mechanisms in Shallow Water Sea Cucumbers (Holothuroidea)

Abstract: The various predator defense mechanisms possessed by shallow water sea cucumbers were surveyed in twelve different species and morphs. While many defense mechanisms such as the presence of Cuverian tubules, toxic secretions, and unpalatability have been identified in holothurians, I hypothesized that the possession of these traits as well as the degree to which they are utilized varies from species to species. The observed defense mechanisms were compared against a previously-derived phylogeny of the sea cucumbers of Moorea. Furthermore, I hypothesized that while the presence of such structures is most likely a result of the species’ placement on a phylogenetic tree, the degree to which they utilize such structures and their physical behavior are influenced by their individual ecologies. The presence of a red liquid secretion was restricted to individuals of the genus Holothuria (Linnaeus 1767) however not all members of the genus exhibited this trait. With the exception of H. leucospilota, which possessed both Cuverian tubules and a red secretion, Cuverian tubules were observed in members of the genus Bohadschia (Ostergren 1896). In accordance with the hypothesis, both the phylogenetics and individual ecology appear to influence predator defense mechanisms. However, even closely related species of similar ecology may differ considerably.

Distribution patterns and growth of two reef flat holothurians, Holothuria atra and Stichopus chloronotus

Abstract: Distribution patterns were studied in two species of aspidochirotes (Holothuria (Halodeima) atra and Stichopus chloronotus ) on a reef flat near Lizard Island, Great Barrier Reef. Abundance and wet weight of all specimens were monitored during six consecutive months (Nov. 1992 — April 1993) in three permanent transects. Additionally, the following physical parameters were determined along the transects: type of bottom coverage, water movement and water depth. As sediment parameters bacterial numbers, chlorophyll and protein content were measured. The mean body weight of both species decreased significantly in quadrats with high coral rubble cover. The main factor influencig the distribution was found to be by water movement. The biomass and abundance of S. chloronotus is lower in areas of high flow while H. atra is more adapted to these zones. The calculated mean growth rate was 12 g ww/month for S. chloronotus during the observation period, but evidence is found that the average annual growth is less then 144 g (12 × 12 g). For H. atra no growth rates could be obtained with the chosen method.