Acanthella danerii sp. nov. (Demospongiae, Bubarida, Dictyonellidae) from Chilean fjords (South Pacific Ocean).

The use of SCUBA diving for marine research in the Chilean fjords has increased the possibility of obtaining information on the sponge assemblages living in this environment. However, much work is still needed to achieve a satisfactory knowledge of the benthos of this wide region. As to sponges, just consider that seventeen new species have been recently described by several authors (Hajdu et al., 2013; Fernandez et al., 2016; Bertolino et al., 2019) with detailed information of this benthic fauna for this area. Aim of this work is the description of a new species of Acanthella (Dictyonellidae van Soest, Diaz Pomponi, 1990), Acanthella danerii sp. nov.. It was collected at "Seno Magdalena" (44°61'48.63" S 72°95'83.12" W) (Chilean fjords) by SCUBA, at 20 m depth, on hard substrates of a vertical wall ending on a rocky bottom that slopes down to 32 m during a survey in August 2016.

Two new species of deep-sea sponges (Porifera, Demospongiae) from submarine canyons of the Sardinian continental margin (western Mediterranean Sea).

Here we describe two new species of deep-sea sponges collected during the exploration of Cold-Water Coral (CWC) banks discovered in the Nora and Coda Cavallo canyons (north-eastern and south coast of Sardinia respectively). Poecillastra tavianii n. sp. differs from the other congeneric species mainly for the dicho- and mesodichotriaenes, never observed in the genus, and the abundance and variety of spirasters. Hymedesmia (Hymedesmia) quadridentata n. sp. is characterized by the presence of two types of chelae. In particular, the unguiferate chelae (round shaft and four teeth at both extremities) represent a peculiar character of the species. Our contribution increases the number of sponge fauna associated to the best known Central Mediterranean CWC habitats to 98 improving the still scant knowledge on the biodiversity of the Mediterranean CWC habitats.

A new sponge species of the genus Antho (Demospongiae, Microcionidae) from the Tyrrhenian deep Sea.

The use of ROVs has greatly enhanced the possibility of obtaining information on living deep sponge communities (Bertolino et al. 2015). The aim of this work is to describe a new Mediterranean species, Antho (Plocamia) sarasiri sp. nov. (Microcionidae Carter, 1875), characterized by dumbbell spicules making up the framework of the choanosomal skeleton (Van Soest et al. 2013). Samples were collected by ROV during an oceanographic survey in September 2012 on board of the R/V 'Astrea' (ISPRA) in "Secca P.ta Fetovaia" (42°43'29.54"N 10° 9'31.64"E) (Elba Island, Tyrrhenian Sea) at 70 m depth. We compared our sample with additional material collected by Sarà Siribelli (1960, 1962).

The sponge fauna of the Seno Magdalena and Puyuhuapi Fjord (Chile), with a description of two new species.

The presence of fjords, islands and channels originating from glacial erosion and ice cap retreat, makes the Chilean benthic biodiversity difficult to explore and study. Our survey of this region allowed the identification of 29 Demospongiae species in total. Two of them are new to science and here described: Biemna lutea sp. nov., and Hamigera cleistochela sp. nov.. Two species (Clathria (Clathria) microxa and Lissodendoryx (Ectyodoryx) patagonica,) are new for the region and the Chilean fjords. Lissodendoryx (Ectyodoryx) patagonica was found for the second time after the original description by Ridley Dendy, 132 years ago. These results - considering the small number of species identified on the whole - are promising and confirm that the marine biodiversity of Chilean fjords is remarkable but not well known yet.

Demosponge diversity from North Sulawesi, with the description of six new species.

Sponges are key components of the benthic assemblages and play an important functional role in many ecosystems, especially in coral reefs. The Indonesian coral reefs, located within the so-called "coral triangle", are among the richest in the world. However, the knowledge of the diversity of sponges and several other marine taxa is far from being complete in the area. In spite of this great biodiversity, most of the information on Indonesian sponges is scattered in old and fragmented literature and comprehensive data about their diversity are still lacking. In this paper, we report the presence of 94 species recorded during different research campaigns mainly from the Marine Park of Bunaken, North Sulawesi. Six species are new for science and seven represent new records for the area. Several others are very poorly known species, sometimes recorded for the second time after their description. For most species, besides field data and detailed descriptions, pictures in vivo are included. Moreover, two new symbiotic sponge associations are described. This work aims to increase the basic knowledge of Indonesian sponge diversity as a prerequisite for monitoring and conservation of this valuable taxon.

The dynamics of a Mediterranean coralligenous sponge assemblage at decennial and millennial temporal scales.

This paper concerns the changes occurred over both decennial and millennial spans of time in a sponge assemblage present in coralligenous biogenic build-ups growing at 15 m depth in the Ligurian Sea (Western Mediterranean). The comparison of the sponge diversity after a time interval of about 40 years (1973-2014) showed a significant reduction in species richness (about 45%). This decrease affected mainly the massive/erect sponges, and in particular the subclass Keratosa, with a species loss of 67%, while the encrusting and cavity dwelling sponges lost the 36% and 50%, respectively. The boring sponges lost only one species (25%). This changing pattern suggested that the inner habitat of the bioconstructions was less affected by the variations of the environmental conditions or by the human pressures which, on the contrary, strongly affected the species living on the surface of the biogenic build-ups. Five cores extracted from the bioherms, dating back to 3500 YBP, allowed to analyse the siliceous spicules remained trapped in them in order to obtain taxonomic information. Changes at generic level in diversity and abundance were observed at 500/250-years intervals, ranging between 19 and 33 genera. The number of genera showed a sharp decrease since 3500-3000 to 3000-2500 YBP. After this period, the genera regularly increased until 1500-1250 YBP, from when they progressively decreased until 1000-500 YBP. Tentatively, these changes could be related to the different climatic periods that followed one another in the Mediterranean area within the considered time span. The recent depletion in sponge richness recorded in the Ligurian coralligenous can be considered relevant. In fact, the analysis of the spicules indicated that the sponges living in these coralligenous habitats remained enough stable during 3000 years, but could have lost a significant part of their biodiversity in the last decades, coinciding with a series of warming episodes.

Diversity of Porifera in the Mediterranean coralligenous accretions, with description of a new species.

Temperate reefs, built by multilayers of encrusting algae accumulated during hundreds to thousands of years, represent one of the most important habitats of the Mediterranean Sea. These bioconstructions are known as "coralligenous" and their spatial complexity allows the formation of heterogeneous microhabitats offering opportunities for a large number of small cryptic species hardly ever considered. Although sponges are the dominant animal taxon in the coralligenous rims with both insinuating and perforating species, this group is until now poorly known. Aim of this work is to develop a reference baseline about the taxonomic knowledge of sponges and, considering their high level of phenotypic plasticity, evaluate the importance of coralligenous accretions as a pocket for biodiversity conservation. Collecting samples in four sites along the coast of the Ligurian Sea, we recorded 133 sponge taxa (115 of them identified at species level and 18 at genus level). One species, Eurypon gracilis is new for science; three species, Paratimea oxeata, Clathria (Microciona) haplotoxa and Eurypon denisae are new records for the Italian sponge fauna, eleven species are new findings for the Ligurian Sea. Moreover, seventeen species have not been recorded before from the coralligenous community. The obtained data, together with an extensive review of the existing literature, increase to 273 the number of sponge species associated with the coralligenous concretions and confirm that this habitat is an extraordinary reservoir of biodiversity still largely unexplored, not only taxonomically, but also as to peculiar adaptations and life histories.