Community structure, diversity, and distribution patterns of sea cucumber (Holothuroidea) in the coral reef area of Sapeken Islands, Sumenep Regency, Indonesia

Sea cucumbers (Holothuroidea) are one of the high value marine products, with populations
under very critical condition due to over exploitation. Data and information related to the condition of sea
cucumber communities, especially in remote islands, like the Sapeken Islands, Sumenep Regency, East
Java, Indonesia, is still very limited. This study aimed to determine the species, community structure
(density, frequency, and important value index), species diversity index, and distribution patterns of sea
cucumbers found in the reef area of Sapeken Islands, using a quantitative descriptive study. This
research was conducted in low tide during the day using the quadratic transect method. Data was
collected by making direct observations of the population under investigation. The results showed that
sea cucumbers belonged to 11 species, from 2 orders: Aspidochirotida, with the species Holothuria hilla,
Holothuria fuscopunctata, Holothuria impatiens, Holothuria leucospilota, Holothuria scabra, Stichopus
horrens, Stichopus variegates, Actinopyga lecanora, and Actinopyga mauritiana and order Apodida, with
the species Synapta maculata and Euapta godeffroyi. The density ranged from 0.162 to 1.37 ind m-2
, and
the relative density was between 0.035 and 0.292 ind m-2
. The highest density was found for H. hilla and
the lowest for S. maculata. The frequency ranged from 0.13 to 0.72, and the relative frequency ranged
from 0.037 to 0.206. The highest frequency value was found for H. hilla and the lowest for S. maculata.
The highest Importance Value Index was observed in the case of H. hilla (0.498), and the lowest was
found for S. maculata (0.072). The Shannon-Wiener (H') species diversity index value was 2.38, and the
evenness value (E) was 0.992, the community tending to be even (E value close to 1). The Index of
Morisita (IM) values range between 1.23 and 2.99, being bigger than 1, meaning that the distribution
pattern of all types of sea cucumbers was clumped.