Suberites zeteki (de Laubenfels, 1936)

Lobate sponge

Phylum Porifera
Class Demospongiae
Order Hadromerida
Family Suberitidae

Description
Growth Form
Encrusting to massive, usually with large lobate or digitate projections.
Color
External color variable, usually red or red-orange, but also yellow, dark green, greenish purple, or turquoise; internal color always yellow-ochre.
Texture and Surface Features
Texture dense, flexible, rubbery, but easy to tear; like cheese. Surface generally smooth, some specimens with goose-bumps
Spicules
Straight sharply pointed tylostyles, large variation in size 300-700 mm, some smaller ones with irregularly shaped or lumpy heads; although ectosome consists of brushes of smaller tylostyles of nearly uniform size (300 mm), no distinct size classes are evident
Habitat
Common as fouling in harbors, especially those with some estuarine conditions, and in Kaneohe Bay, primarily on floating docks, dock pilings and mangrove roots, also on hulls of ships.
Distribution
Hawaiian Islands
Oahu - all leeward harbors and Kaneohe Bay
Kauai - Nawiliwili Boat Harbor
Native Range
Caribbean or west coast Panama
Present Distribution
Caribbean, Panama, Hawaiian Islands, Guam
Mechanism of Introduction
Unintentional introduction, most likely as fouling on ships' hull.
Impact
Fouling organism. Ecological impact unstudied, some competition for space with native species likely.
Ecology
Reproduction
Like all sponges, S. zeteki is capable of asexual reproduction by fragmentation of the adult. Details regarding sexual reproduction of this species are unknown. (See Reproduction of Haliclona caerulea for general description of sponge reproduction.)
Feeding
Sponges are filter feeders, continuously circulating water through their bodies. Microscopic food particles are removed from water by specialized collar cells. Digestion is intracellular.
Remarks
De Laubenfels (1950) thought S. zeteki to be the most abundant in Hawaii, especially in shallow-water protected environments such as boat harbors and embayments. Recent observations of sponge populations in these habitats around Oahu, suggest that the more recently introduced sponge, Mycale armata, not present during de Laubenfels' time, is now more abundant and widespread.
De Laubenfels (1950) considered the Hawaiian specimens to be identical to Laxosuberites zeteki which he described in 1936, found at both ends of the Panama Canal. We have examined the holotype of L. zeteki and concur with de Laubenfels' determination.
Mycale cecilia de Laubenfels 1936, a common West Indian species, is also very common in shallow water locations such as Honolulu and Pearl Harbors, leading him to speculate that: "The 2 Panamanian forms conceivably may have been bought to Hawaii on ship bottoms, one being abundant on those [ships] dry-docked at Pearl Harbor, or conversely, they may have been taken from Hawaii to Panama."
References
De Laubenfels, M.W. 1950. The sponges of Kaneohe Bay, Oahu. Pac. Sci. 4(1): 3-36.