# Potential transoceanic dispersal of Geodia cf. papyracea and six new tetractinellid sponge species descriptions within the Hawaiian reef cryptofauna

## TL;DR

This study explores new sponge species in Hawaiian reefs and investigates the possible spread of a sponge from the Caribbean to Hawai‘i.

## Contribution

The paper introduces six new sponge species and provides evidence for transoceanic dispersal using molecular and morphological methods.

## Key findings

- Geodia papyracea may have dispersed from the Caribbean to Hawai‘i.
- Six new sponge species from the genus Stelletta and one from Stryphnus were described.
- Molecular and morphological data improved species identification accuracy.

## Abstract

Kāne‘ohe Bay has historically been known for the introduction of alien species from the Caribbean and the Western Indo-Pacific. Recent efforts that explore the reef cryptofauna have shown that in addition to the diversity of non-indigenous species, patch reef environments are rich with undescribed species. Here we integrate molecular phylogeny and systematics to distinguish introduced species from those that are potentially native or endemic. We focus on the order Tetractinellida and document the potential transoceanic dispersal of Geodia papyracea from the Caribbean to Hawai‘i. Our integrative approach allowed us to describe new species of Stelletta (Stelletta kela sp. nov., Stelletta hokunalohia sp. nov., Stelletta kuhapa sp. nov., Stelletta hokuwanawana sp. nov., Stelletta apapaola sp. nov.) and one new species of Stryphnus (Stryphnus huna sp. nov.); all collected from the reef cryptofauna via the use of Autonomous Reef Monitoring Structures. Specimens were barcoded using 28S and COI molecular markers, providing insights into the phenotypic plasticity of sponges and the phylogenetic placement of these new species based on morphological characters. Using both molecular phylogeny and traditional taxonomy enhances the accuracy of species identification and classification, contributing to a broader understanding of sponge biodiversity within the Hawaiian archipelago.