The term "sandfish" commonly refers to a specific species of sea cucumber known as Holothuria scabra. Here is a description of the sandfish sea cucumber:

1.     Appearance: The sandfish sea cucumber has a cylindrical and elongated body, resembling a cucumber. It can grow to a length of about 30 centimeters (12 inches) or more. The skin is typically rough, and the color can vary, often ranging from reddish-brown to dark brown.

2.     Habitat: Sandfish sea cucumbers are found in sandy or muddy seabeds, primarily in shallow coastal waters of the Indo-Pacific region. They are known to inhabit areas with soft substrates, where they burrow into the sand for protection.

3.     Behavior: Sandfish sea cucumbers are notable for their ability to move through the sand with ease. They have a unique mechanism for "swimming" in the substrate, using their muscular body and tube feet to create a peristaltic motion that allows them to bury and unbury themselves.

4.     Diet: Sea cucumbers, including the sandfish, are detritivores, feeding on organic matter and microorganisms present in the sand or mud. They ingest sediment and extract nutrients from it.

5.     Economic Importance: The sandfish sea cucumber is of economic importance, especially in the context of the sea cucumber fisheries and aquaculture. It is harvested for its high market demand, particularly in some Asian countries where sea cucumbers are considered a delicacy with potential medicinal properties.

6.     Aquaculture: Due to overharvesting and concerns about the sustainability of wild populations, there have been efforts to cultivate sandfish sea cucumbers through aquaculture. This helps meet the demand for sea cucumbers while reducing pressure on wild populations.

7.     Traditional Uses: Sea cucumbers, including the sandfish, are used in traditional medicine in some cultures. They are believed to have various health benefits, although scientific evidence supporting these claims is limited.