The Marine fauna of New Zealand. Squat lobsters (Crustacea, Decapoda, Chirostyloidea) / Kareen E. Schnabel.

Accepted for publication by Michelle Kelly & Sadie Mills, 31 March 2020, published 30 June 2020.

Series and Managing Editor Michelle Kelly, NIWA. Technical Editor Sadie Mills, NIWA.

Keywords: Anomura, Chirostylidae, Eumunididae, Sternostylidae, Chirostylus, Eumunida, Gastroptychus, Heteroptychus, Pseudomunida, Sternostylus, Uroptychodes, Uroptychus, systematics, taxonomy, DNA barcoding, new species,seamounts, deep sea, associations, corals, Lord Howe Rise, Louisville Seamount Chain, Norfolk Basin, Norfolk Ridge, West Norfolk Ridge, Lord Howe Island, Lord Howe Rise, Challenger Plateau, Three Kings Ridge, Norfolk Basin, Macquarie Ridge, South Pacific, Wanganella Bank, New Zealand EEZ, Australian EEZ, International Waters.

‘Squat lobster’ is the popular name for two distantly related groups of decapod crustaceans that have a similar body form, the Galatheoidea and Chirostyloidea. They are conspicuous elements of most marine environments, from shallow coastal waters to abyssal depths, in unusual habitats such as hot vents and cold seeps, and across most latitudes worldwide. Current global diversity stands at around 1300 species of galatheoids and around 345 chirostyloids. Over the last four decades, they have been the subject of considerable taxonomic and systematic study internationally, but the New Zealand squat lobster fauna has not been comprehensively examined. New Zealand species of squat lobsters (Superfamily Chirostyloidea) are presented in this work, which considers and revises records spanning nearly 150 years of collections in the region (1874–2017). Prior to this study, 38 species from two of the four families of the Chirostyloidea were known from the New Zealand region. The New Zealand chirostyloid fauna now comprises 86 species in three families and eight genera, of which 26 species are new to science and 23 are new records. All available material is examined and listed, all species are illustrated, and diagnoses and keys are provided. A wider phylogenetic study of the group is under way but preliminary results of DNA barcoding are presented and discussed. Collection records often point to a host association between the squat lobsters and other macroinvertebrates, most commonly large black corals or gorgonian octocorals, and occasionally sponges. These are usually concentrated on vulnerable marine habitats such as seamounts or deep-sea ridges. Additionally, three of the four families have a shorter larval development which has been suggested as the reason for the more limited regional distribution ranges. As expected, the New Zealand chirostyloid fauna shows a close affinity with the tropical SW Pacific and eastern Australian species, with a limited number of widespread Indo-West Pacific species present, and over 40% are currently considered endemic. Results of the present study demonstrate a considerably higher species richness than previously known, more than doubling the known fauna of the region. Many global regions remain entirely or partially unstudied, implying that a huge potential for species discovery remains globally. The inventory of the New Zealand region is considered complete, with only a few potentially new chirostyloid squat lobsters to be recorded in the future. The inventory of the other superfamily, Galatheoidea, is still far from complete, however.