Amphimedon species (Porifera: Niphatidae) from the Gulf of Aqaba, Northern Red Sea: Filling the gaps in the distribution of a common pantropical genus
Helmy, Tamer
Van, Rob W. M.
Soest
Zootaxa
2005
859
1
18
D3NF
[264,540,284,310]
Demospongiae
Niphatidae
Amphimedon
Animalia
Haplosclerida
11
12
Porifera
species
hamadai
sp. nov.
Material examined. Holotype ZMAPor. 17343, El Gharkana, 10m, coll. T. Helmy, 30072000.
Description.Colour: Brown with purple shades. Shape: Irregularly lobate ( Figure 5A), sometimes with fingerlike projections 3–4 cmin diameter, with some randomly distributed clearly raised oscula, rims 1 mmhigh, and 2–3 mmin diameter. The sponge is solidly attached to the substratum with its whole underside. Surface: Bumpy, more or less smooth, nonpunctate on the flattened parts. Texture: Compressible and difficult to tear. Skeleton.Ectosomal skeleton ( Figure 5B) composed of thin spicule tracts 283342 µm in thickness, with inconspicuous spongin sheath enveloping 7–12 spicules, forming isotropic meshes 140180250 µm in diameter. Choanosomal skeleton ( Figure 5C) anisotropic with quadrangular meshes 90115130 µm in diameter formed by spicule tracts in a ladder like construction. The primary tracts are 404550 µm in diameter and are cored by approximately 10 spicules in cross section. They are interconnected by secondary fibres of 202530 µm diameter cored by fewer spicules. Spicules: Oxeas ( Figure 1F), short straight, 4855 60 x 2–3µm.
Etymology.The species is named after Mohamed Helmy for his help during the collection of the species. Ecology.Always attached to dead corals or rocks in the coral reef community.
Distribution.Found in Ras Nusrani, Shark Observatory and Hurgada (pers. obs. T.H.).
Remarks.The new species differs from A. dinae sp.nov.and A. jalae sp.nov.as well as from A. chlorosand Indian Ocean A. brevispiculifera( Dendy, 1905)and A. delicatula(Dendy, 1889)in having unusually short and at the same time relatively thick oxeas. From A. dinae sp.nov.and A. jalae sp.nov.it differs furthermore in lacking a punctate surface. From A. chlorosit differs in being more irregular in shape and having a different live colour.