Phakellia cf. tropicalis Alvarez & Hooper, 2009

Alvarez, Belinda, De Voogd, Nicole J. & Soest, Van, 2016, Sponges of the family Axinellidae (Porifera: Demospongiae) in Indonesia, Zootaxa 4137 (4), pp. 451-477 : 464-466

Phakellia cf. tropicalis Alvarez & Hooper, 2009

( Fig. 2 , 8 )

Phakellia tropicalis Alvarez & Hooper, 2009: 29 ; Przeslawski et al. 2014, 2015 (listed only)

Material examined. ZMA Por. 0 9017, Indonesia, NE coast of Sumba, E of Melolo, Nusa Tenggara, 9.9033°S, 120.725°E, 50 m depth, 15 September 1984, coll. R.W.M. van Soest on Snellius II Expedition, Sta. 061/ V/18. ZMA Por. 0 9139, Indonesia, NE coast of Sumba, E of Melolo, Nusa Tenggara, 9.8917°S, 120.7117°E, 75 m depth, 13 September 1984, coll. R.W.M. van Soest on Snellius II Expedition, Sta.051, dredge. ZMA Por. 12218, Indonesia, Saleh Bay, N coast of Sumbawa, Lesser Sunda Islands, 8.3166°S, 117.6833°E, 274 m depth, 14 February 1900, coll. Siboga Expedition, Sta. 312, trawl. ZMA Por. 0 1226, Indonesia, Lesser Sunda Islands, 8.5°S, 119.125°E, 73 m depth, 12 February 1900, coll. Siboga Expedition, Sta. 312, trawl. ZMA Por. 12252, 12268, 12356, Indonesia, Solor Strait, mid channel off Kampong Menanga, Lesser Sunda Islands, 8.4152°S, 123.043°E, 113 m depth, 8 February 1900, coll. Siboga Expedition, Sta. 305, dredge.

Remarks. The material examined includes a collection of specimens from the area of Lesser Sunda very similar in shape and skeletal organisation to Phakellia tropicalis . The Lesser Sunda specimens are found deeper, down to 274 m depth, than the northern Australian populations, and have thicker and longer spicules. Some specimens are infested with the Parazoanthus . Further illustrations ( Fig. 8 ) and spicules measurements ( Table 7 ) are provided here for comparative purposes.

This species was first described from northern Australia and assigned to Phakellia provisionally because it shares characteristic of the skeleton with the dictyonellid genus Acanthella , and surface characteristics with axinellid genera such as Axinella and Cymbastela . The species is genetically related to Axinella and Dragmacidon spp. ( Alvarez et al. 2000; Redmond et al. 2013), which are characterized by different morphologies, skeletal organisation and spicule composition. Alvarez & Hooper (2009) also suggested that the species might belong to a new genus which could accommodate species of erect form and ‘bubaris-like’ skeletons currently assigned to hidden Acanthella and Phakellia .

Distribution. The species was first described for the Sahul Shelf (with the majority of records reported from northern Australia (i.e Bonaparte Gulf and Arnhem Coast to Gulf of Carpenteria MEOW) ( Alvarez & Hooper 2009). It is also found in the Northwest Australian Shelf province (Alvarez & Fromont unpublished data). Assuming that this material is conspecific with P. tropicalis , the distribution of the species is wider than initially thought and should be extended to the Central-Indo Pacific province ( Fig.2 ).

x 3.7–9.5µm (7±1.6) x 9 –16.4µm (13.8±2)

NTM Z004463* Wessel Is 293.1–800µm (553.4±134.6) 273.6–658.2µm (439.6±111.1)

x 4.4–8.4µm (6.6±1.1) x 8.3–16µm (11.2±2.2)

QM G312926* Papua New Guinea 277.8–696.3µm (476.4±117.6) [24] 239.6–490.6µm (343.5±69.5)

x 4.2–8.4µm (6.3±1.1) x 5.9–11.5µm (8.7±1.8)

*Data from Alvarez & Hooper (2009)

Figures

FIGURE 2. Map showing the geographical location of the described species.

FIGURE 8. Phakellia cf. tropicalis. A, ZMA Por. 12356, preserved specimen. B, ZMA Por. 12356, light microphotograph of skeleton, C, drawing of spicules. Scale bars: A, 2 cm; B, 500 µm; D, 100 µm.

Tables

TABLE 7. Spicule dimensions of Phakellia cf. tropicalis.

Specimen Locality	Strongyles	Styles
ZMA Por. 12218 Sumbawa, Lesser Sunda	429.3–1068µm (735.7±154.2) x 7.4–17.7µm (11.4±2.6)	186.4–1097.1µm (646±249.2) x 6–24µm (15.6±4.3)
ZMA Por. 12268 Solor Strait,. Lesser Sunda	518.6–1086.4µm (784.2±181.7) [16] x 8–18.5µm (12.5±2.5) [16]	249.1–707.2µm (401.6±96.9) x 11.1–18.2µm (14.3±1.8)
P. tropicalis
NTM Z005847 Stevens Rock (holotype)*	284.1–651.2µm (480.4±105.3) x 3.8–8.4µm (5.7±1.2)	231.9–549.2µm (385.7±82.5) x 7.3–430.9µm (29.8±83.6)
NTM Z004488* Bynoe Harbour	222.8–670.7µm (435.5±135)	353.9–703.6µm (484.6±102.2)