Taxonomy of some halisarcida and homosclerophorida (Porifera: Demospongiae) from the indo‐pacific

Abstract

Several sponges with a thin encrusting form and of fragile construction have been collected in the Indo‐Pacific, and have proved difficult to differentiate, let alone identify, without recourse to electron microscopy. Here we re‐describe Halisarca melana de Laubenfels, 1954 from Palau, and H. metabola de Laubenfels, 1954 from Majuro Atoll in the Marshall Islands from new material, emphasising field characters such as coloration in life, surface features, and histological details accessible by light microscopy. Using similar characters two new species of Halisarca, H.ferreus sp. nov., from Zanzibar, Tanzania, and H. cerebrum sp. nov., from Palau, are recognised and described. Another genus belonging to a different subclass of Demospongiae also has fragile construction and encrusting growth form; this is Oscarella, and two new species of this genus are also described, O. stillans sp. nov. from the Philippines, and O. nigraviolacea sp. nov., from Pemba Island, Tanzania.

Keywords:

• Porifera
• Demospongiae
• Homosclerophorida
• Halisarcida
• Halisarca
• Oscarella
• Palau marine lake
• Tanzania
• Philippines
• new species

Notes

Author for correspondence.