A tropical eastern Pacific invasive brittle star species (Echinodermata: Ophiuroidea) reaches southeastern Florida

Peter W. Glynn, Renata Alitto, Joshua Dominguez, Ana B. Christensen, Phillip Gillette, Nicolas Martinez, Bernhard M. Riegl, Kyle Dettloff

Research output: Chapter in Book/Report/Conference proceedingChapter

2 Scopus citations

Abstract

The invasive brittle star Ophiothela mirabilis (family Ophiotrichidae), a tropical Indo-Pacific endemic species, first reported in Atlantic waters off southern Brazil in 2000, has extended its range northward to the Caribbean Sea, to the Lesser Antilles in 2011, and was first reported in south Florida in January 2019. Its occurrence in southeast Florida extends along nearly 70 km of coastline, from near the Port of Miami, Miami-Dade County, northward to Deerfield Beach, Broward County. It occurs abundantly as an epizoite on octocorals, attaining population densities of 25 individuals and more per 10-cm long octocoral stem. The surface texture of octocoral hosts (rough, smooth) did not affect the densities of the ophiuroid epizoites, and there were significantly greater abundances on octocorals during two winter sampling periods than in the summer. Beige and orange-coloured morphs are sometimes present on the same octocoral stem. Gut content analysis supported a suspension feeding mode, revealing essentially identical ingested items in both colour morphs with a preponderance of amorphous detritus and filamentous algae. Molecular genetic evidence (COI & 16s) has established the identity of O. mirabilis and its relationship to invasive Brazilian populations. The orange and beige morphs form two distinct, but closely related lineages that may represent two separate introductions. The orange morph shares haplotypes with Brazilian and Caribbean specimens suggesting a further range expansion of the ‘original’ invasion. The beige morph, however, shares haplotypes with specimens from the Mexican Pacific and Peru and potentially represents a secondary introduction. Traits promoting dispersal and establishment of this species in new habitats are manifold: vagility and ability to cling tightly to diverse host taxa (e.g. sponges, cnidarians, bryozoans, and echinoderms), frequent asexual reproduction (fissiparity), suspension feeding, including a wide range of dietary items, possession of integument-covered ossicles and arm spines offering protection from predators, and an effective competitive edge over associated microbiota for substrate space.

Original languageEnglish (US)
Title of host publicationAdvances in Marine Biology
EditorsBernhard M. Riegl
PublisherAcademic Press
Pages443-472
Number of pages30
Edition1
ISBN (Print)9780128215296
DOIs
StatePublished - Jan 2020

Publication series

NameAdvances in Marine Biology
Number1
Volume87
ISSN (Print)0065-2881
ISSN (Electronic)2162-5875

Keywords

  • Brazil
  • Invasive ophiuroid
  • Octocoral epizoite
  • Ophiotrichidae
  • South Florida

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Aquatic Science

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