A new species of habitat–forming Suberites (Porifera, Demospongiae, Suberitida) in the Benguela upwelling region (South Africa)

Abstract

S. dandelenae sp. nov. is described from the west coast of South Africa and occurs at depths of 80-500 m among unconsolidated sediments. Specimens can reach 40 cm in length and in some areas off South Africa, up to 18 tons/km2 can be collected in a single demersal trawl. Morphologically, the sponge is straw yellow, massive with rounded lobes and has a velvety surface: it is characterized by subradiate, irregular reticulation of bundles of tylostyles and tylostrongyles. Specimens of S. dandelenae sp. nov. have three size classes of tylostyles with the largest tylostyle lengths being 516 μm (441-614 μm), medium tylostyle lengths being 352 μm (307-422 μm) and the shortest tylostyle lengths being 215 μm (153-288 μm). Apart from the presence of tylostyles, some specimens of S. dandelenae sp. nov. also possess centrotylostongyles/oxeas, tylostrongyles and microacanthostrongyles spicules. We have used morphological characters to distinguish this species and a molecular marker (cox1) to conform that all specimens are the same species. At the spicular level, S. dandelenae sp. nov. is characterized by a complex of spicule types that vary with specimen size. Following a histological investigation and re-description of the holotypes of S. ficus (Johnston, 1842) and S. tylobtusus Lévi, 1958, and comparisons with S. carnosus (Johnston, 1842), S. stilensis Burton, 1933, and other Suberites species described from the African region, it is clear that the new species is different in spicule morphology, spicule size and external morphology. For example, microacanthostrongyles are not present in S. tylobtusus and S. carnosus, whilst S. ficus possesses a second, non-spinose category of microstrongyles. Suberites tylobtusus has tylostyles that are sometimes polytylote, with heads either well formed, pear shaped or reduced, in only one size catogory. The 'tylobtuse' condition of the tylostyles is also different to the kidney-shaped and centrotylostrongyles found in S. dandelenae sp. nov. Suberites stilensis Burton, 1933 has larger and thicker tylostyles (800 μm length x 10 μm thick) than those of S. dandelenae sp. nov. A comparative analysis of partial cox1 sequences from morphologically diverse specimens of S. dandelenae sp. nov. with published material indicates that all specimens comprise a monophyletic clade. The combined morphological and genetic data support the designation of Suberites dandelenae sp. nov.

A critically endangered estuarine limpet’s only two populations are genomically and morphologically distinct

“…It is recognized that differences in size could be related to the fact that poikilotherms grow larger in colder water, as previously shown for a co-distributed estuarine snail, Nassarius kraussianus (Teske et al, 2007). However, the combination of numerous additional morphometric characters that together make the shells readily distinguishable from each other strongly suggests that the two populations are morphometrically unique as well as being genomically distinct, and thus need to be managed as distinct Hui, 2020), some of which have subsequently been described as morphologically distinct species (Dawson & Griffiths, 2012;Nangammbi, Herbert & Teske, 2016;Samaai et al, 2017). Within the genus Siphonaria, sufficient genetic differences (up to 23 mutational steps) have been recognized between populations of what was previously regarded as a single species, S. pectinata, to split western Atlantic populations from those of eastern Atlantic and Mediterranean, assigning the name S. naufragum to the former and S. pectinata to the latter, and recognizing a third species, S. placentula, from the Cape Verde Archipelago (Giribet & Kawauchi, 2016).…”

“…previously overlooked) species or subspecies. Cryptic speciation based on the phylogenetic species concept has been demonstrated for numerous other marine animals in the region by means of genetic methods (von der Heyden, 2009; Teske et al, 2011; Greenan, Griffith & Santamaria, 2018; Mbongwa et al, 2019; von der Heyden, Mbongwa & Hui, 2020), some of which have subsequently been described as morphologically distinct species (Dawson & Griffiths, 2012; Nangammbi, Herbert & Teske, 2016; Samaai et al, 2017). Within the genus Siphonaria , sufficient genetic differences (up to 23 mutational steps) have been recognized between populations of what was previously regarded as a single species, S. pectinata , to split western Atlantic populations from those of eastern Atlantic and Mediterranean, assigning the name S. naufragum to the former and S. pectinata to the latter, and recognizing a third species, S. placentula , from the Cape Verde Archipelago (Giribet & Kawauchi, 2016).…”

Two new sponge species (Demospongiae: Chalinidae and Suberitidae) isolated from hyperarid mangroves of Qatar with notes on their potential antibacterial bioactivity

“…Suberitidae Schmidt, 1870 and Genus Suberites Nardo, 1833 due to its massively globularlobate shape, possession of a spicule complement consisting only of tylostyles, and the presence of an ectosomal palisade formed of bouquets of smaller tylostyles than those of the choanosome [48]. Genus Suberites has 80 species worldwide [48][49][50] [54]. A sixth species Suberites carnosus (Johnston, 1842) was previously recorded from the Indian Ocean, more specifically from the Seychelles and Minicoy Islands and the coast of India (Mumbai) [55][56][57].…”

“…novaezealandiae and var. ramosus are not now considered to inhabit any marine province in the Indian Ocean [50] and therefore this species and its variants were discarded from this comparison. A comparison with the aforementioned biogeographically related species is presented in Table 2.…”

“…nov. in terms of morphology and habitat preferences. Suberites bengalensis is a deepsea species recorded from 1190 m [49]; S. tylobtusus, when living, is a bright orange colour [50]. Suberites diversicolor has spicules of a similar size range to S. luna.…”