Integrative systematics illuminates the relationships in two sponge-associated hydrozoan families (Capitata: Sphaerocorynidae and Zancleopsidae)

Abstract

An integrated approach using morphological and genetic data is needed to disentangle taxonomic uncertainties affecting the hydrozoan families Sphaerocorynidae and Zancleopsidae. Here we used this approach to accurately characterise species in these families, identify the previously unknown polyp stages of the genera Euphysilla and Zancleopsis, which were originally described exclusively based on the medusa stages, describe a new sphaerocorynid genus and species, and assess the phylogenetic position of the two families within the Capitata. The monotypic genus Astrocoryne was found to be a synonym of Zancleopsis. Astrocoryne cabela was therefore transferred to the genus Zancleopsis as Zancleopsis cabela comb. nov. The new polyp-based genus and species Kudacoryne diaphana gen. nov. sp. nov. was erected within the Sphaerocorynidae. Both taxa are primarily based on genetic data, but the introduction of this new genus was made necessary by the fact that it clustered with the genera Heterocoryne and Euphysilla, despite showing Sphaerocoryne-like polyps. Interestingly, the species analysed in this work showed contrasting biogeographical patterns. Based on our data and literature records, some species appear to have a wide circumtropical range, whereas others are limited to few localities. Overall, these results lay the ground for future investigations aimed at resolving the taxonomy and systematics of these two enigmatic families.

The pressures and opportunities for coral reef preservation and restoration in the Maldives

“…The majority of species are invertebrates, including 400 species of mollusks, 120 species of copepods, 15 species of amphipods, over 145 species of crabs and 48 species of shrimps (Convention on Biological Diversity). This census of species is subject to change as these species are often cryptic, morphologically very simple and difficult to study from a taxonomical point of view (Montano et al, 2015a,b;Maggioni et al, 2016Maggioni et al, , 2017aMaggioni et al, ,b, 2021.…”

Odd family reunion: DNA barcoding reveals unexpected relationship between three hydrozoan species

“…Hydrozoan species have often been described based on a single life stage, which has led to the development of parallel taxonomies with separate names for polyps and their respective medusae ( Brooks, 1886 ; Cornelius, 1977 ). Many of these names are still in use, and the process of unifying these classification systems is far from finished ( Schuchert, Hosia & Leclére, 2017 ; Maggioni et al, 2021 ). Even when the relationships between polyps and medusae are known, some stages have never been observed in nature and their morphology is described solely based on animals reared in laboratory and/or for juvenile or immature specimens ( Russell, 1953 ; Bouillon et al, 2006 ).…”

Systematics and character evolution of capitate hydrozoans

“…This class has been estimated to be the second most species‐rich within Cnidaria, after Anthozoa (Appeltans et al., 2012), and new taxa are continually being added (e.g. Toshino et al., 2019; Galea and Maggioni, 2020; Maggioni et al., 2021; Tödter et al., 2023). Yet, part of its diversity is still unknown (Appeltans et al., 2012), also as a consequence of the pervasive occurrence of morphologically cryptic species (Postaire et al., 2016, 2017; Maggioni et al., 2020a, 2022a).…”

“…Despite several taxonomic and systematic issues being clarified by Nawrocki et al (2010), some relationships are still uncertain and many genera and species are currently lacking DNA data. Zancleida, on the other hand, shows a greater family and genus diversity, and some recent works focused on the diversity and evolution of certain families or clades (Miglietta et al, 2019;Maggioni et al, 2021Maggioni et al, , 2022b. A striking example of taxonomic and systematic uncertainties in Zancleida is represented by the family Zancleidae Russell, 1953, the most diverse of the clade, which has been demonstrated to be polyphyletic and to contain several cryptic species (Maggioni et al, 2018(Maggioni et al, , 2020a(Maggioni et al, , 2022a.…”