A new Acanthotetilla sponge from the Southwest Atlantic (Tetillidae, Spirophorina, Tetractinellida, Demospongiae), with an updated discussion on the diversity, distribution and morphologic characters of Acanthotetilla spp.

Acanthotetilla is a genus of tetillid sponges diagnosed by the presence of medium-sized, heavily spined oxeas, which are known as megacanthoxeas (or simply acanthoxeas). Currently, seven species are known worldwide: three from the Western Atlantic (A. gorgonosclera, A. rocasensis and A. walteri), three from the Western Indian (A. hemisphaerica, A. enigmatica and A. seychellensis) and one from the Western Pacific (A. celebensis). A megacanthoxea-bearing specimen was obtained from the Fernando de Noronha Archipelago, Southwest Atlantic, in 2016. It is described here as a new Acanthotetilla, namely, A. noronhensis sp. nov. This new species has two categories of megacanthoxeas, like A. celebensis from Celebes/Sulawesi Sea, Indonesia. However, the former differs from the latter, as well as from other congeners, by the combination of endolithic habit and spiculation. Acanthotetilla noronhensis sp. nov. is known on the basis of a single specimen from a large collection of sponges from Fernando de Noronha. Besides, the species was not found in other sponge collections from different areas of Brazil, including oceanic areas. Thus, the new species has probably a low abundance and restricted distribution, alike all other known Acanthotetilla species, aside A. celebensis, which (regardless its low abundance) occurs in a large sector of the western Pacific. Despite A. noronhensis sp. nov. and A. celebensis being separated by a wide geographic distance, the unique occurrence of two categories of megacanthoxeas might suggest closer phylogenetic relationship and biogeographic history as well. A wider discussion on the diversity, distribution and morphologic characters of Acanthotetilla spp. is supplied in this study. A comparative taxonomic table and a taxonomic identification key to Acanthotetilla spp. is supplied as well.

Checklist, diversity descriptors and selected descriptions of a highly diverse intertidal sponge (Porifera) assemblage at Costa do Descobrimento (Bahia, Brazil).

Costa do Descobrimento is located in southern Bahia, Brazil, and only 22 species of sponges (Porifera) were known from the area until now, despite its important reef formations. In the present study, we report a checklist of the sponges of Costa do Descobrimento and their distribution in the studied reefs, with several species illustrated in life. We also describe nine new sponge records for this region, some of which are new records for Brazil, or new records of species previously only poorly known. We present alpha and beta diversity indices and compare the sponge assemblage of the sampled locations. Four reefs were considered: two fringing reefs (Arraial D'Ajuda-AA and Coroa Vermelha / Mutá-CVM) and two offshore Municipal Marine Park "Parque Municipal Marinho- (P.M.M. Coroa Alta-CA and P.M.M. Recife de Fora-RF). A total of 229 specimens were collected (224 Demospongiae, 2 Homoscleromorpha and 3 Calcarea). These were classified in 101 morphotypes. Studied materials included representatives of 15 orders, 34 families and 48 genera. The richest orders are Haplosclerida (29 spp.), Poecilosclerida (15 spp.) and Tetractinellida (11 spp.). The richest families were Chalinidae (24 spp.), Clionaidae (7 spp.) and Mycalidae and Suberitidae (6 spp. each). The richest genus is, by far, Haliclona (20 spp.). Only 13 species were shared among all four reefs surveyed, namely Amphimedon viridis, Cinachyrella alloclada, C. apion, Cladocroce caelum, Cliona varians, Dysidea robusta, Mycale (Naviculina) diversisigmata, Niphates erecta, Spirastrella hartmani, Tedania (Tedania) ignis, Terpios fugax, Tethya bitylastra and T. maza. The reefs with the highest richness were CA and CVM, and the lowest richness was observed in RF. The most similar reefs in terms of species composition were CA and CVM, while AA and RF were more dissimilar to the previous reefs, but also from each other. While the difference among CA, CVM and AA was mainly explained by species turnover, RF differed from the previous based on its lower richness (nestedness component). Even though CA and CVM were the richest reefs, AA presented the highest number of exclusive species, highlighting the uniqueness of this reef, and urging the inclusion of local beachrock fringing reefs in a more holistic conservation strategy at Costa do Descobrimento.

Microbiome diversity from sponges biogeographically distributed between South America and Antarctica.

Sponges from South America and Antarctica are evolutionarily closely related. Specific symbiont signatures that could differentiate these two geographic regions are unknown. This study aimed to investigate the microbiome diversity of sponges from South America and Antarctica. In total 71 sponge specimens were analyzed (Antarctica: N = 59, 13 different species; South America: N = 12, 6 different species). Illumina 16S rRNA sequences were generated (2.88 million sequences; 40K ± 29K/sample). The most abundant symbionts were heterotrophic (94.8 %) and belonged mainly to Proteobacteria and Bacteroidota. EC94 was the most abundant symbiont and dominated the microbiome of some species (70-87 %), comprising at least 10 phylogroups. Each of the EC94 phylogroups was specific to one genus or species of sponge. Furthermore, South America sponges had higher abundance of photosynthetic microorganisms (2.3 %) and sponges from Antarctica, the highest abundance of chemosynthetic (5.5 %). Sponge symbionts may contribute to the function of their hosts. The unique features from each of these two regions (e.g., light, temperature, and nutrients) possibly stimulate distinct microbiome diversity from sponges biogeographically distributed across continents.

Three new Hymedesmia Bowerbank, 1864 (Demospongiae, Poecilosclerida, Hymedesmiidae) from the Southeast Pacific (Peru and Chile).

Despite its 2000 km long shoreline, to date less than 50 sponge species have been reported from the entire Peruvian coast. A large collecting effort targeting marine sponges was undertaken between 2007 and 2009, yielding a comprehensive collection of nearly 900 samples, whose taxonomic study is underway. Three new species of Hymedesmiidae are presently described from the Peruvian coast, all belonging in Hymedesmia (Hymedesmia), one of which also found in Chile. Hymedesmia (H.) santarositae sp. nov., from Isla Santa Rosa (Paracas), is characterized by the presence of microstrongyles next to sigmas. Hymedesmia (H.) peruana sp. nov., from Isla Foca (Piura), is diagnosed by its three categories of acanthostyles, and single categories of tornotes and arcuate isochelae. Hymedesmia (H.) humboldti sp. nov., from Moquega and Arequipa regions in Peru, and Antofagasta and Atacama regions in Chile, is diagnosed by its two categories of acanthostyles, and single categories of (aniso)strongyles and arcuate isochelae, the latter abundant at the surface. An identification key for Hymedesmia spp. from the South-eastern Pacific, South-western Atlantic, the Sub-Antarctic and the Antarctic is provided.

New species of Crella (Pytheas) Topsent, 1890 and Crellomima Rezvoi, 1925 (Crellidae, Poecilosclerida, Demospongiae) from Chilean shallow and Argentinean deep waters, with a synthesis on the known phylogenetic relationships of crellid sponges.

Here, we describe four new species of Crellidae Dendy, 1922 and discuss characters and relationships from published molecular phylogenies including crellid sponges. New species proposed are Crella (Pytheas) chiloensis Fernandez, Gastaldi, Pardo Hajdu, sp. nov., from southern Chile (15 m depth), C. (P.) desventuradae Fernandez, Gastaldi, Zapata-Herndez Hajdu, sp. nov., from Desventuradas Archipelago (1020 m depth), Crella (P.) santacruzae Fernandez, Gastaldi, Thompson Hajdu, sp. nov., from deep waters off Argentina (750 m depth) and Crellomima sigmatifera Fernandez, Gastaldi Hajdu, sp. nov., from the Chilean fjords region (ca. 20 m depth). These new species are set apart from each other and from known species mainly due to aspects of their spiculation. Chelae microscleres and acanthostyles supply characters that might be used to infer phylogenetic relationships and to verify the monophyly of Crella Gray, 1867 and Crellidae, which has seemingly been contradicted by preliminary molecular data available in the systematics literature. Our own interpretation of phylogenetic affinities, in the light of morphological characters from previous taxonomic studies, argues for a classification reassessment of materials (vouchers) included in these molecular phylogenies, especially in the case of Crella incrustans (Carter, 1885). We argue that currently available molecular phylogenetic outcomes for crellid sponges are not supportive of the polyphyly of Crella and Crellidae.

An update on the diversity of marine sponges in the southern gulf of Mexico coral reefs.

Until now, 127 species of marine sponges have been recorded in the southern Gulf of Mexico (SGoM). In this study, we describe the sponge fauna recorded on 16 coral reefs of the SGoM, defined as the Mexican waters of the Gulf of Mexico (GoM), during a period from 2005 to 2019. We report 80 sponge species, including 34 first geographic records for the southern GoM region. The latter are fully described and illustrated, taking into account 24 that represent new records for the GoM: Agelas conifera, Agelas sventres, Agelas wiedenmayeri, Prosuberites carriebowensis, Desmanthus meandroides, Cliona aprica, Cliona dioryssa, Placospongia ruetzleri, Haliclona (Gellius) megasclera, Haliclona (Reniera) aff. portroyalensis, Neopetrosia proxima, Xestospongia arenosa, Calyx podatypa, Shiphonodictyon xamaycaense, Acarnus innominatus, Iotrochota arenosa, Polymastia tenax, Svenzea cristinae, Svenzea flava, Svenzea tubulosa, Svenzea zeai, Timea stenosclera, Stellettinopsis megastylifera, Suberea flavolivescens. The present work highlights the understimated and remarkable diversity of reef-associated sponges within the Campeche Bank Coral reef systems. Present work data was compiled with existing published information to produce an updated list of 161 known sponges in the southern GoM.

Sponges from Doumer Island, Antarctic Peninsula, with description of new species of Clathria (Axosuberites) Topsent, 1893 and Hymeniacidon Bowerbank, 1858, and a re-description of H. torquata Topsent, 1916.

Antarctic sponges were mainly studied from trawling or dredging (shallow and deep water) during pioneering oceanographic expeditions carried out since the late 19th century. More recently, sponge collections by SCUBA diving have allowed the detection of species in more cryptic habitats such as rocky walls. In this study, we analyzed Antarctic sponges collected by SCUBA (in 2016 to 2018; shallower than 25 m) around Doumer Island (Palmer Archipelago, Western Antarctic Peninsula-WAP), where only five sponge species have been known. We gathered over 215 specimens, most part identified; 18 known species and one new species. Clathria (Axosuberites) retamalesi sp. nov., is set apart from its congeners on account of the combination of its habit, categories and dimensions of spicules. The East Antarctic material named as Hymeniacidon spec. (3397 m depth) from the Gauss scientific collection has been related to the shallow species H. torquata Topsent, 1916. We described H. torquata based in several specimens (n= 51) from Doumer Island (WAP), only ca. 41 km from Petermann Island (the type locality). Spicules of H. torquata are smaller than the ones present in the Hymeniacidon spec. material, which is here named Hymeniacidon hentscheli sp. nov., since it does not fit into any known cold water species of Hymeniacidon from Antarctica or the Southern Hemisphere, due to a combination of habit, oscula shape, and spicule dimensions. Only five sponge species were previously known from Doumer Island, also collected by SCUBA. Our findings suggest that the ongoing study of collections of sponges assembled at Doumer Island will still yield new taxonomic findings.

Taxonomy of deep-water tetillid sponges (Porifera, Demospongiae, Spirophorina) from Brazil, with description of three new species and new characters.

Since the 19th century the deep-sea sponges from Brazil have been studied and many of them are still being discovered. This study describes five species of tetillid sponges from deep waters of the Brazilian economic exclusive zone; three are new, one is a new occurrence, and another is a known species which is here analyzed. The new species found are: Cinachyrella clavaeformis sp. nov. from the Columbia Seamount (85 m depth), Cinachyrella strongylophora sp. nov. from the Almirante Saldanha Seamount (270 m depth) and Craniella curviclada sp. nov. from slope of the Espírito Santo Basin (500 m depth). The two new species of Cinachyrella possess microacanthoxeas like those found in Cinachyrella kuekenthali (Uliczka 1929); this last species occurs in Caribbean region (4-100 m depth) and in N, NE and SE Brazil (0.2-100 m depth). The type material of Craniella corticata (Boury-Esnault 1973); from NE Brazil (75 m depth), has been found to be a synonym of Cinachyrella kuekenthali. Craniella crustocorticata van Soest 2017; from the Guyana shelf and slope (618-500 m depth), is here reported from the slope of NE and SW Brazil (400-700 m depth). A disorganized choanosomal skeleton (in Cinachyrella clavaeformis sp. nov.), strongyles (in Cinachyrella strongylophora sp. nov.) and a single-layered cortex of tangential oxeas (in Craniella crustocorticata) are new diagnostic characters that have led us to propose slight amendments in the definitions of Cinachyrella Wilson 1925 and Craniella Schmidt 1870. We discuss these and other morphological characters as well as their usefulness in Tetillidae. The diversity, distribution and bathymetry of tetillid sponges from Brazil are discussed and our knowledge of the composition of deep-sea sponges (deeper than 100 m) off Brazil is updated.

Cinachyrella anatriaenilla sp. nov., a new tetillid sponge with microacanthoxeas from American Samoa in the South Pacific.

Several sponges from American Samoa, collected by the Coral Reef Research Foundation, Republic of Palau, were tentatively identified by one of us as Acanthotetilla cf seychellensis (Thomas 1973), due to the possession of relatively small acanthose oxeas, compared to those of other species of the genus Acanthotetilla Burton 1959. These sponges were later compared to Cinachyrella australiensis (Carter 1886), taking into account the lack of conspicuous spination on the acanthose oxeas and general features of spiculation and skeletal organisation. The specimens were later considered to represent a new species of the genus Cinachyrella Wilson 1925, after a careful comparison was made between the American Samoan specimens and C. australiensis which also contains small acanthose oxeas. Several recent molecular phylogenetic studies have confirmed the generic assignment of one of the American Samoan specimens as belonging to Cinachyrella. Cinachyrella anatriaenilla sp. nov., described herein, is the fifth of 40 Cinachyrella spp. that contain lightly spined microacanthoxeas.

Lissodendoryx (Ectyodoryx) Lundbeck, 1909 (Coelosphaeridae, Poecilosclerida, Demospongiae) from Southern Chile: new species and a discussion of morphologic characters in the subgenus.

Our ongoing studies of the Chilean sponge fauna revealed four new species of Lissodendoryx (Ectyodoryx) that are described here, including three from the fjord's region (< 30 m depth, L.(E.) ballena sp. nov., L. (E.) corrugata sp. nov.,      L. (E.) coloanensis sp. nov.), and one from the deep waters off Diego Ramírez Archipelago (ca. 2000 m, L. (E.) diegoramirezensis sp. nov.). In addition, the type of L. (E.) anacantha was revised and found to bear much larger acanthostyles than originally reported. Our results revealed skeletal architectures quite distinct from that reported from the type species of L. (Ectyodoryx), and not predicted in the current diagnosis of Lissodendoryx, requiring an amended diagnosis. Ectosomal megascleres also set the majority of the new species apart from the type species of L. (Ectyodoryx), which does not have terminally microspined (sub)tylotes. This character is widespread in Lissodendoryx and might be pointing to phylogenetic affinities across the current subgeneric arrangement. Further morphologic characters and alternative phylogenetic scenarios are discussed, including hymedesmiid and myxillid affinities of the species described here.

Phylogeny of Tetillidae (Porifera, Demospongiae, Spirophorida) based on three molecular markers.

Tetillidae are spherical to elliptical cosmopolitan demosponges. The family comprises eight genera: namely, Acanthotetilla Burton, 1959, Amphitethya Lendenfeld, 1907, CinachyraSollas, 1886, CinachyrellaWilson, 1925, Craniella Schmidt, 1870, Fangophilina Schmidt, 1880, Paratetilla Dendy, 1905, and Tetilla Schmidt, 1868. These genera are characterized by few conflicting morphological characters, resulting in an ambiguity of phylogenetic relationships. The phylogeny of tetillid genera was investigated using the cox1, 18S rRNA and 28S rRNA (C1-D2 domains) genes in 88 specimens (8 genera, 28 species). Five clades were identified: (i) Cinachyrella, Paratetilla and Amphitethya species, (ii) Cinachyrella levantinensis, (iii) Tetilla, (iv) Craniella, Cinachyra and Fangophilina and (v) Acanthotetilla. Consequently, the phylogenetic analysis supports the monophyly of Tetilla, a genus lacking any known morphological synapomorphy. Acanthotetilla is also recovered. In contrast, within the first clade, species of the genera Paratetilla and Amphitethya were nested within Cinachyrella. Similarly, within the fourth clade, species of the genera Cinachyra and Fangophilina were nested within Craniella. As previously postulated by taxonomists, the loss of ectodermal specialization (i.e., a cortex) has occurred several times independently. Nevertheless, the presence or absence of a cortex and its features carry a phylogenetic signal. Surprisingly, the common view that assumes close relationships among sponges with porocalices (i.e., surface depressions) is refuted.