Who’s there? – First morphological and DNA barcoding catalogue of the shallow Hawai’ian sponge fauna

<div><p>The sponge fauna has been largely overlooked in the Archipelago of Hawai’i, notwithstanding the paramount role of this taxon in marine ecosystems. The lack of knowledge about Porifera populations inhabiting the Hawai’ian reefs limits the development of ecological studies aimed at understanding the functioning of these marine systems. Consequently, this project addresses this gap by describing the most representative sponge species in the shallow waters of the enigmatic bay of Kane’ohe Bay, in O’ahu Island. A total of 30 species (28 demosponges and two calcareous sponges) living associated to the reef structures are here reported. Six of these species are new records to the Hawai’ian Porifera catalogue and are suspected to be recent introductions to these islands. Morphological descriptions of the voucher specimens are provided, along with sequencing data of two partitions involving the mitochondrial cytochrome oxidase subunit 1 (COI) marker and a fragment covering partial (18S and 28S) and full (ITS-1, 5.8S and ITS-2) nuclear ribosomal genes. Species delimitations based on genetic distances were calculated to valitate how taxonomic assignments from DNA barcoding aligned with morphological identifications. Of the 60 sequences submitted to GenBank ~88% are the first sequencing records for the corresponding species and genetic marker. This work compiles the first catalogue combining morphological characters with DNA barcoding of Hawai’ian sponges, and contributes to the repository of public databases through the Sponge Barcoding Project initiative.</p></div

Chondrilla mixta.

<p>A alive specimen; B-D sphaerasters; E oxysphaeraster.</p

Mycale (Mycale) grandis.

<p>A alive specimen; B ectosomal skeleton; C choanosomal skeleton; D fibres echinated by the larger anisochelae; E mycalostyle; F anisochela I; G anisochela II; H anisochela III; I sigma I; J sigma II; K raphides in trichodragma.</p

Comparison of the tylostyles and of other morphological characteristics among <i>S</i>. <i>diversicolor</i>, <i>S</i>. <i>aurantiacus</i> and its synonimies.

<p>Comparison of the tylostyles and of other morphological characteristics among <i>S</i>. <i>diversicolor</i>, <i>S</i>. <i>aurantiacus</i> and its synonimies.</p

<i>Callyspongia (Toxochalina)</i> cf. <i>pseudotoxa</i>.

<p>A alive specimen; B ectosomal skeleton; C, D choanosomal skeleton; E stout oxea; F, G oxhorn toxas I with variable angle of curvature; H oxhorn toxa II.</p

Pseudoceratina purpurea.

<p>A live specimen; B magnification with in evidence the smooth surface.</p

Echinodictyum asperum.

<p>A fresh collected specimen; B choanosomal skeleton; C oxea; D straight style; E club-shaped acanthostyle; F magnification of the acanthostyle head; G magnification of the acanthostyle tip.</p

Spicule measurements of <i>Mycale (M</i>.<i>) grandis</i>.

<p>Spicule measurements of <i>Mycale (M</i>.<i>) grandis</i>.</p

Tedania (Tedania) ignis.

<p>A alive specimen; B alive specimen with flattened projections; C choanosomal skeleton; D irregular isotropic reticulation of the choanosomal skeleton; E style; F tornote; G magnification of the microspined tip; H onychaete I; I onychaete II.</p

Sponge specimens not identified at the species levels.

<p>A Leucosolenida; B <i>Leucetta</i> sp.; C <i>Callyspongia (Cladochalina)</i> sp.; D <i>Gelliodes</i> sp.; E <i>Dysidea</i> sp. 1, SPO12; F <i>Dysidea</i> sp. 1, SPO18; G <i>Dysidea</i> sp. 2.</p