Neopetrosia exigua ( Kirkpatrick, 1900 )

Setiawan, Edwin, Erpenbeck, Dirk, Wörheide, Gert & De Voogd, Nicole J., 2018, Bearing the wrong identity: A case study of an Indo-Pacific common shallow water sponge of the genus Neopetrosia (Haplosclerida; Petrosiidae), Zootaxa 4500 (1), pp. 43-58 : 46-47

Neopetrosia exigua ( Kirkpatrick, 1900)

Figure 1B , 2B , 3B , Table 1

Petrosia exigua Kirkpatrick, 1900: 139 , Pl, XII, Fig. 7, Pl. XIII, Fig. 4

Material examined: Holotype: BMNH 1898.12.20.49, Australia, Christmas Island, Indian Ocean.

Description (amended from Kirkpatrick 1900): Sponge forms a hard, thick, nodulated crust, smooth surface, showing an irregular reticulate pattern formed by pore-areas, oscules are measured in a range of 1-5 mm in diameter.

Colour. Pale gray brown in the dry condition.

Skeleton. Forms of slender main lines of fibres passing vertically to the surface and connected at right angles to this plane by closely packed single spicules, so as to form circular or obscurely polygonal tubes about 70 mm in diameter. The skeletal network is dense and irregularly oriented.

Spicules. Oxeas in a size range of 70- 113.8 -130 x 5- 7.3 -10 µm. Remarks: Kirkpatrick (1900) remarked that spicules are considerably smaller than the allied species Petrosia similis (less than half the size). We also discovered that only a very small fragment of the type material is left in the BMNH collections.

Figures

FIGURE 1. A Neopetrosia chaliniformis (Thiele, 1899) holotype ZMB2889, B Neopetrosia exigua (Kirkpatrick, 1901), holotype BMNH1898.12.20.49, C Xestospongia pacifica Kelly-Borges & Bergquist, holotype AM Z4999, and D Neopetrosia pandora de Laubenfels, 1954, holotype USNM4806. Scale bar= 1 cm.

FIGURE 2. Oxea from the holotypes of A Neopetrosia chaliniformis (Thiele, 1899) ZMB2889, B Neopetrosia exigua (Kirkpatrick, 1901), BMNH1898.12.20.49, C Xestospongia pacifica Kelly-Borges & Bergquist, AMS Z4999, and D Neopetrosia pandora de Laubenfels, 1954, USNM4806. Scale bar= 50 µm

FIGURE 3. Spicule arrangement in holotypes of A Neopetrosia chaliniformis (Thiele, 1899) ZMB2889, B Neopetrosia exigua (Kirkpatrick, 1901), BMNH1898.12.20.49, C Xestospongia pacifica Kelly-Borges & Bergquist, AMS Z4999, and D Neopetrosia pandora de Laubenfels, 1954, USNM4806. Scale bar= 150 µm.

FIGURE 4. In situ photo of sponges identified as N. exigua, that were collected in (A) Northern Territory Australia, QM G303302, (B) Palau, QM G306321, (C) Tonga, QM G313297 and (D) a sponge identified as N. chaliniformis that was photographed in Probolinggo, East Java, Indonesia.