Haliclona (Rhizoniera) indistincta ( Bowerbank, 1866 )

Haliclona (Rhizoniera) indistincta ( Bowerbank, 1866) View in CoL

( Figure 14 View FIGURE 14 )

Isodictya indistincta Bowerbank, 1866: 290–292 .

Haliclona indistincta, de Weerdt, 1986: 129–132 View in CoL .

Material examined: ESFM-POR / 2017-499 , S10, 25 m, on coralligenous habitat, 1 specimen , ESFM-POR / 2017- 42 , S26, 10 m, on stone, 1 specimen ; ESFM-POR / 2017-499 , S31, 10 –20 m, on stone, 1 specimen .

Description: Specimens are encrusting (height: 0.5–0.9 cm) and have a punctate, slightly irregular, surface. Exhalant canals are clearly visible.The color is brown in alcohol. The consistency is soft and friable ( Figure 14a View FIGURE 14 ). The osculum is slightly elevated from the sponge surface and is 1.5–3 mm in diameter. The choanosomal skeleton was an anisotropic reticulation with distinct pauci-multispicular primary tracts composed of 2 to 9 spicules, and paucispicular secondary lines that were composed of 1 to 4 overlapping spicules. However, a third paucimultispicular tract forms a triangular reticulation. Its spicules consist of fine fusiform oxea (110–150 × 3–7.5 μm) ( Figure 14b–d View FIGURE 14 ). The choanosomal skeleton has an isotropic reticulation ( Figure 14c View FIGURE 14 ). Spongin is present in small amounts only at the tips of the spicules.

Habitat and distribution: This species was reported at depths of 0–30 m under rocks and in shaded habitats ( Carballo & Garcia-Gómez 1994). It has an Atlantic-Mediterranean distribution ( de Voogd et al. 2024). It was previously reported from the Azores (Topsent 1892), the Celtic Sea ( Bowerbank 1866, de Weerdt 1986), and the western Mediterranean (Alboran Sea) ( Carballo & Garcia-Gómez 1994). This species is a new addition to the marine fauna of the eastern Mediterranean Sea.