The sea squirts were gone, and all of a sudden the glass sponges had tripled" in number, Richter says.
Caption: Glass sponges, which provide habitat for feather and brittle stars in frigid Antarctic waters, flourished following the collapse of the Larsen A ice shelf.
Basket sponges, Geodia, and glass sponges comprised 66.
Only the basket sponges appeared to be affected; Geodia and glass sponges showed no evidence of necrosis.
More rigid species, such as Geodia, often found attached to cobbles, would probably be either crushed or rolled over; and glass sponges, flexible but usually associated with finer substrates and attached by tufts of spicules extending into the substrate (Brusca and Brusca, 1990), would be pulled from the substrate in their entirety.
Konecki and Targett (1989) note that glass sponges serve as important nesting and refuge sites for Antarctic fishes, and destruction of sponge communities by bottom trawling could have an impact on fish ecology in the region.
In addition, five glass sponges, Rhabdocalyptus sp.
Glass sponges are so called because their skeletons are built from glasslike silica minerals, not carbonates.
Such reef-building glass sponges disappeared from the fossil record about 120 million years ago, about the same time that diatoms, a type of single-celled marine algae with cell walls built of silica, first appeared in large numbers, says Johnson.
Reef-building glass sponges had previously been found only in the protected waters of a near-shore strait, so researchers had presumed that the creatures could thrive only in certain restricted ecological niches.
Only glass sponges (class Hexactinellida) are known to be able to arrest flagella in response to mechanical stimuli (see review by Leys and Meech, 2006).
In situ feeding and metabolism of glass sponges (Hexactinellida, Porifera) studied in a deep temperate fjord with a remotely operated submersible.