A new species of glass sponge (Hexactinellida: Sceptrulophora: Uncinateridae) from the Weijia Seamount in the northwestern Pacific Ocean

In this article we report on a hexactinellid sponge new to science, Tretopleura weijicus sp. nov., which was collected from the Weijia Seamount in the northwestern Pacific Ocean at a depth of 1995 m. Its blade-like and branching body form, the primary choanosomal framework consisting of multiaxial longitudinal strands without synapticula, and the presence of sceptrules suggest placement within the family Uncinateridae Reiswig, 2002, which is also supported by molecular phylogenetic evidence from COI and 16S sequences. The absence of swollen dermal spurs or regular pentactins and the presence of two types of discohexasters characterize it as a new species. More specimens should be collected to revise the generic characters.

A new glass sponge genus (Hexactinellida: Euplectellidae) from abyssal depth of the Yap Trench, northwestern Pacific Ocean

In this article we report on a hexactinellid sponge new to science, Rhizophyta yapensis gen. et sp. nov., which was collected from the Yap Trench in the northwestern Pacific Ocean at an abyssal depth of 4159–4779 m. Its fungus-like body form with long peduncle and absence of hypodermalia suggest placement within the euplectellid subfamily Bolosominae Tabachnick, 2002, whereas molecular phylogenetic evidence suggests that it is sister to all remaining Euplectellidae Gray, 1867. Its rhizophytous method of attachment to the substrate, hitherto unknown from bolosomine Euplectellidae, a veil of pentactins covering the peduncle, and the presence of toothed discohexasters as the only type of microscleres, clearly characterize it as a new genus. The intraspecific divergence between holotype and paratypes of the new species is examined with both morphological and molecular approaches. This report represents the first record of a hexactinellid sponge from the Yap Trench.

A new hexactinellid sponge from the Silurian of the Pentland Hills (Scotland) with similarities to extant rossellids

ABSTRACTThe Pentland Hills sponge fauna (Llandovery, Telychian) consists of an unusual, aberrant assemblage, but of low diversity. A new specimen of a unique sponge, Eoghanospongia carlinslowpensis gen. et sp. nov., is described from the classic locality of R82. The mushroom-shaped, probably stalked body (peduncle attachment to body not exposed) resembles that of some living rossellids, especially Caulophacus. The sponge also shows prominent projecting pentactins and monaxon derivatives – a spicule type diagnostic of the Rossellidae among living taxa, albeit in a robust form not described from extant sponges, including Caulophacus or other pedunculate lyssacinosidans. Certain attribution to the Rossellidae is not possible from the single specimen, largely because of weak preservation of the primary spicule skeleton, but no other fossil or modern sponges show any significant similarity to it. Although similarly early relatives of the Rossellidae have recently been described from elsewhere, the new sponge is even more unexpected in being from a shallow-water environment, making the absence of rossellids through the rest of the Palaeozoic much more problematic.

New Hexactinellid Sponge Chaunoplectella megapora sp. nov. (Lyssacinosida: Leucopsacidae) from Clarion-Clipperton Fracture Zone, Eastern Pacific Ocean

The new Hexactinellid sponge Chaunoplectella megapora sp. nov. reported in this study was collected from the COMRA contract area, the western part of Clarion-Clipperton Fracture Zone (CCFZ) in the eastern Pacific Ocean at a depth of 5258 m. This sponge’s extraordinary multiporous body with the presence of unique codonhexasters, sigmatocomes, toothed discohexasters and hemidiscohexasters, as well as stellate disocohexasters, characterizes it as a new species in the genus Chaunoplectella. This report presents the first record of family Leucopsacidae at this site in the eastern Pacific Ocean.