Protosuberites sp.

Protosuberites sp.

Fig. 24 View Fig

Material examined (3 specimens)

SWEDEN • 1 spec.; Saltbacken ; 59.0832° N, 11.2242° E; 24Apr. 2018; Mats Larsson leg. [MM-180424- 1]; SCUBA; LAR-180424-4583–4584; GenBank no.: OM436223 View Materials (coxI); voucher: GNM Porifera 1114 GoogleMaps • 1 spec.; Svartejan ; 59.1102° N, 11.3219° E; 4 Dec. 2018; Mats Larsson leg. [MM-181204-1]; SCUBA; LAR-181204-8156, 8159–8160; GenBank nos: OM628824 View Materials (coxI), OM415645 View Materials (28S D3- D5); voucher: GNM Porifera 1115 GoogleMaps • 1 spec.; same collection data as for preceding; LAR-181218-8476, 8478, 8481; voucher: GNM Porifera 1116 GoogleMaps .

Description

The specimens were all thin encrusting, 6 mm of maximum diameter ( Fig. 24A–C View Fig ). The alive colour was pale yellow or greenish yellow turning beige when preserved in ethanol. The surface is microhispid, with visible spicules in bouquets/bundles ( Fig. 24D View Fig ). The pores as well as the oscula are visible. Oscules are elevated in translucid chimneys ( Fig. 24A–B View Fig ).

Skeleton

Skeleton is confused apart from the bouquets/bundles of tylostyles on the surface. Megascleres are tylostyles ( Fig. 24E View Fig ), usually straight and with a very defined head, rarely displaced in the shaft ( Fig. 24F View Fig ) or in ring shape. They are in a wide size range, but not separated in discrete size classes ( Fig. 24C View Fig ), measuring 74.4– 187.9 –449.9± 101.8× 2.3– 3.6 –3.4 ±1.4 µm (N= 13). Some tylostyles are slightly curved near the tyle. No microscleres were found.

Remarks

There are currently nine valid species of Protosuberites reported in the Mediterranean and the NEA. The external morphology in colour and in habitus is similar to what is described for the common European P. denhartogi van Soest & de Kluijver, 2003 , and this includes the subsurface patterns. However, our specimens present tylostyles smaller than what is reported for P. denhartogi , which presents the smallest size of tylostyles (74 µm in length) in one occurrence whereas the remaining spicules are all bigger than 100 µm, averaging 248 µm in size. In contrast, our specimens have an average spicule size of 189 µm. We were inclined to call these specimens P. denhartogi , but coxI does not group with a sequence of P. denhartogi ( Fig. 2 View Fig ). Therefore, we prefer to call these specimens Protosuberites sp. for now. More specimens of Protosuberites need to be barcoded to begin to understand this group.