Holothuria

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

Reproductive cycle of the sea cucumber Holothuria forskali (Holothuriida: Holothuriidae) in the Ría de Vigo (NW of Spain)

Abstract: Introduction: The exploitation of the sea cucumber (Holothuria (Panningothuria) forskali) in Ria de Vigo (NW Spain) is recent (2015) and it has been done until now with scarce or no information about some key biological aspects as reproduction, recruitment or growth. Objective: To describe the reproductive cycle of H. forskali in Ria de Vigo. Methods: We sampled fortnightly throughout 2018. We calculated gonadal condition indices (GCI) and gametogenic stages by classic histological methods. Results: The reproductive cycle of H. forskali in the Ria de Vigo is characterized by a sexual resting stage during spring, when temperature and daylight hours are lower; the beginning of gametogenesis during summer, when temperature is higher, daylight hours longer and the sea bottom is rich in nutrients; then, a period of spawns interspersed with a gonadal restoration during autumn and winter, when temperature is lower and food is scarce. Sex ratio is 1:1, however, the studied population is not synchronized, because females initiate maturation earlier. The comparison of the histological results with GCI indices suggest that GCI is a good indicator for gonadal stage. Fishery management strategies, such as a closure period, must be adapted to the reproductive stage. We recommend avoiding fishing between November and February to increase spawning potential ratio and, consequently, recruitment.

The occurence & distribution of two black sea cucumber species in pombo island, central maluku (indonesia)

Abstract: The so called “black sea cucumber” are found in Indonesia as several species including Holothuria atra , H. leucospilota , H. coluber , H. excellens and H. turriscelsa. The local community of Wainure village near Pombo Island in central Maluku had reported that most sea cucumbers inhabiting the island are the black sea cucumbers or locally known as “teripang hitam.” They are occasionally consumed but not exploited excessively by the locals. The goals of this study are to identify the species of black sea cucumbers inhabiting Pombo Island and map their distribution to understand the microhabitats of black sea cucumber. Two field surveys conducted in March and April 2014 collected more than 550 individuals of black sea cucumbers that belong to two species Holothuria (Halodeima) atra Jaeger, 1833, and Holothuria (Mertensiothuria) leucospilota Brandt, 1835. Furthermore, distribution maps of these two species show that they are found only along the SE to SW coast of the island. Such distribution may relate to the availability of marine vegetation, as well as boulders and stones that provide shelters to the organism. The distribution maps also show that H. atra has a wider distribution than H. leucospilota in Pombo Island. This may be due to the semi-cryptic habit of H. Leucospilota ’s (i.e. hiding its posterior body under rocks or crevices), making its distribution restricted to areas that provide ample shelters.

Microbial population in the coelomic fluid of stichopus chloronotus and holothuria (Mertensiothuria) leucospilota collected from Malaysian waters

Abstract: This preliminary study aimed to isolate and identify microbes that inhabit the coelomic fluid of two local species of sea cucumbers collected from Malaysian waters - a ‘gamat’ species i.e. Stichopus chloronotus Brandt, 1835 and the most abundant ‘timun laut’ species in Malaysia i.e. Holothuria (Mertensiothuria) leucospilota (Brandt 1835). Phylogenetic analyses of partial 16S rRNA mtDNA gene sequences suggested the presence of at least eight microbial genera i.e. five bacterial genera - Bacillus, Exiguobacterium, Pseudomonas, Stenotrophomonas and Vibrio - isolated from the coelomic fluid of H. leucospilota and three genera of gram-positive bacteria from the Micrococcaceae family - Kytococcus, Micrococcus and either Kocuria or Rothia - isolated from the coelomic fluid of S. chloronotus. We speculate that less diverse microbial population in S. chloronotus as compared to H. leucospilota could be due to a number of environmental factors e.g. penetration of light surrounding the habitats of both species, the feeding behaviour of H. leucospilota and the higher level of antimicrobial properties of coelomic fluid in S. chloronotus. In terms of antimicrobial-resistance capability test, an isolate from genus Pseudomonas that is suspected to be P. alcaligenes exhibited high resistance towards streptomycin. Another isolate from genus Stenotrophomonas that was suspected to be S. maltophilia showed moderate resistance towards streptomycin and lower resistance towards kanamycin. Both isolates were from the coelomic fluid of H. leucospilota. Tetracycline inhibited the growth of all bacterial isolates tested. Further studies with more specimens of S. choronotus and H. leucospilota from broader geographical locations and the use of complete mtDNA genes along with morphological approaches for species identification may facilitate to provide better insights into the microbial population in the coelomic fluid of both local sea cucumber species.

Antioxidant and antibacterial activities in 21 species of Indonesian sea cucumbers

Abstract: Sea cucumbers are marine organisms with uses in food, cosmetics, and medicine This study aimed to identify Indonesian sea cucumbers with high antioxidant and antibacterial activities Twenty-one sea cucumber species were used for this study Antioxidant capacity was evaluated using the 2,2-diphenyl-β-picrylhydrazine assay Antibacterial activity was assessed using the disk diffusion assay, whereas the resazurin-based assay was employed to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) Volatile compounds possibly related to the biological activity of sea cucumbers were analyzed via gas chromatography–mass spectrometry (GC–MS) Holothuria atra had the strongest antioxidant capacity (IC50 = 1422 ± 087 µg µL−1) Stichopus vastus displayed the best antibacterial activity against Staphylococcus aureus, whereas Stichopus ocellatus extract was most potent against Vibrio cholerae Holothuria albiventer, which controlled Bacillus subtilis most effectively while also being active against S aureus and V cholerae, was the optimal antimicrobial species H albiventer and Actinopyga echinites inhibited B subtilis growth at 125 µg µL−1 The MBC tests indicated that the antibacterial activities of sea cucumbers at the MIC were bacteriostatic, rather than bactericidal, in nature GC–MS analysis uncovered long-chain fatty acids that might be associated with the antibacterial activities of sea cucumbers