New species calls an unfortunate looking sea cucumber its home
September 23, 2016
Many species depend upon others to live. Suckerfish are well known examples. Attaching themselves to their host, be that a whale, turtle or shark, the suckerfish can move freely across its body removing parasites and loose skin. It’s a mutual agreement, the suckerfish gets a meal and the others get a free clean.
The shell of the new species of bivalve, Borniopsis mortoni. Credit: Dr. Ryutaro Goto
Scientists recently discovered another species that clings on to sea cucumbers in mudflats at the mouth of the Souzu River in Japan. Named as Borniopsis mortoni, the cucumber dwelling creature is a bivalve species of the Galeommatoidea family (bivalves include clam, oyster and mussel families). It chose as its host the Patinapta ooplax, an unfortunate looking and kind-of earthworm-like sea-cucumber.
The author encourages you to come to your own conclusions as to what this
particular sea cucumber looks like. Credit: Mr. Hiroshi Ishikawa
B.mortoni clings on to body of the sea cucumber by its foot and its byssal threads, silky fibres that help bivalves latch on for dear life to whatever their surface of choice is. Most of the bivalve families either chose sand, mud or rocks to live on. But B.mortoni decided to buck this trend and the discovery makes B.mortini only the third of the Borniopsis family to live on sea cucumbers.
The research team led by Ryutaro Goto, of the Department of Ecology and Evolutionary Biology at the University of Michigan, and Hiroshi Ishikawa, an amateur mollusc researcher (or malacologist for the pros) believe that the adaption may be for protection from predators.
As its host has a long, narrow body, it is believed that B.mortoni’s small size, it stretches up to 4.1mm in length, is an adaptation to suit its living quarters. This could also aid its cramped living conditions as the scientists discovered that there could be more than 10 B.mortoni living upon the same host at the same time, side-by-side.
Unlike the suckerfish and its hosts, it remains to be seen what the sea cucumber gets out of this arrangement.