Spicular Complement Research Articles

Morphological and molecular analysis of Ephydatia fluviatilis (Porifera: Spongillida: Spongillidae) from Nanjing, China

We present a comprehensive morphological description of Ephydatia fluviatilis collected in Nanjing for the first time in studies of freshwater sponges in China, based on scanning electron micrography of the sponge meshwork, the megascleres, the gemmules, and the delicate gemmuloscleres, in comparison with relevant data reported worldwide. The morphotype revealed in this study shows a peculiar spicular complement of the skeleton composed of two types of megascleres (the normal oxeas and occasional styles) with abundant tiny, centrally distributed microspinoses, gemmules (ca. 440 μm in diameter) bearing two types of spinose decoration on the shaft (i.e., erect long spines and microspinoses). We report the first complete ITS sequences of the morphotype of E. fluviatilis from China, which, combined with homologous sequences of related taxa from GenBank, are used in a phylogenetic analysis in order to understand the species relationship within Ephydatia and neighbouring taxa. Combining the ITS phylogeny and the gemmulosclere morphotypes, we identify three clades in the paraphyletic genus Ephydatia that are distinguished by different birotule gemmulosclere morphotypes for gemmule-bearing species. Multiple losses of gemmules within endemic taxa, as previously proposed, are confirmed in this study in a phylogenetic context obtained herein. Additionally, genetic similarities are found in some morphologically diverse species, likely indicating recent endemism leading to morphological specialization. Considering the diverse fossil record of Ephydatia from Cenozoic sedimentary strata of wide geographic ranges, we hypothesize that Ephydatia might have a deep root in the Paleogene or earlier and experienced a rapid, Quaternary radiation with emergences of specialized endemic species that lost gemmules under glacial-interglacial paleoenvironment.

Insight into the evolutionary history of freshwater sponges: A new genus and new species of Spongillida (Porifera: Demospongiae) from Upper Cretaceous (Maastrichtian) Deccan intertrappean lacustrine deposits of the Malwa Group, Central India

New fossil freshwater sponges are recorded from the Upper Cretaceous (Maastrichtian) intertrappean lacustrine sediments of Malwa Group associated with Deccan volcanic province in Central India. The micro-palaeontological analysis of diagnostic spicular morphotraits supports the ascription of these fossils to the order Spongillida. The description of new genus Palaeocorvospongilla (family Palaeospongillidae) is based on the entire spicular complement of Palaeocorvospongilla cretacea gen. et sp. nov. It is distinguished from other extant and fossil Spongillida by pseudobirotules and oxeas with morphometries, indicating a very large size of skeletal microscleres from Deccan intertrappean fossils. From an evolutionary point of view, data on Indian fossils indicate a clear trend of long term conservative morphology in the evolutionary history of this genus since the Upper Cretaceous. Fossil data also indicate an early splitting (Mesozoic) and spreading of freshwater sponges Spongillida taxa in the Asian continent.

Integrative taxonomy reveals the first record and a new species for the previously monotypic genus Tethytimea (Tethyida: Tethyidae) in the Gulf of Mexico.

The first record of the previous monotypic genus Tethytimea and the description of a new species from cryptic habitats of Gulf of Mexico are presented. Tethytimea carmelita sp. nov., is a red orange cushion shaped sponge (about 5 mm thick) with a tuberculate to granular surface. The spicular complement is formed by tylostyles (200-1120 µm length), smooth spheres (12.5-55 µm in diameter); megasters-spheroxyasters (12.5-90 µm in diameter); and micrasters in two categories: oxy-strongylasters (12.5-27.5 µm in diameter) and spherotylasters (2.5-25 µm in diameter). The new species differs from the only species known T. tylota (Hentschel, 1912) mainly by differences in the size and shape of spicules. T. tylota possesses tylostyles in two size categories; megasters include giant oxyspherasters up 250 µm and micrasters in a single category. Additionally, to the morphological characteristics, we integrated partial sequences of a large sub-unit ribosomal 28S rDNA gene region (D1-D2 domains), in order to establish the molecular taxonomic position of our new species (and genus). Tree topologies (Maximum Likelihood and Bayesian Inference) were congruent in phylogenetic hypothesis, retrieving the Order Tethyida as monophyletic. In this clade, the family Timeidae was separated from the other families Tethyidae + Hemiastrellidae. Inside this latter group and according to the taxonomic hypothesis based on morphology, Tethytimea carmelita sp. nov. was included in Tethyidae clade, together with a sequence of Tethya sp. (AY626300), forming a sister group with representatives of genera Xenospongia and Thectitethya. Our new species constitutes the second valid known species for the genus Tethytimea and the first record of genus for the Atlantic Ocean.

Coping with brackish water: A new species of cave-dwelling Protosuberites Porifera: Demospongiae: Suberitidae) from the Western Mediterranean and a first contribution to the phylogenetic relationships within the genus.

We used both morphological and genetic approaches to investigate and to describe a new Mediterranean sponge species of the genus Protosuberites from the estuarine-anchialine Bue Marino Cave of Sardinia (Tyrrhenian Sea). The morphotraits of the specimens were compared versus congeneric species with the strongest affinities, covering the genus geographic range worldwide. Protosuberites mereui sp. nov. is light yellow, thinly encrusting, devoid of any special ectosomal skeleton, with spicular complement of tylostyles of three size classes, single or arranged in bundles/tufts, with round to suboval heads. The new species is characterized by an exclusive diagnostic trait recorded for any cave-dwelling Protosuberites i.e. suboval and basally plated resting bodies with a foraminal aperture ornate by a collar. Resting bodies were found in the basal spongin plate firmly adhering to the substratum singly or in small groups. Also the rare, small tylostyles with a sinuous shaft and a typical mushroom-like head were never recorded in the Western Mediterranean and Atlantic species of the genus. The phylogenetic reconstruction using maximum likelihood (ML) and Bayesian Inference (BI) analyses (COI, 18S rRNA, and 28S rRNA) recovered a robustly supported sister relationship between the Mediterranean P. mereui sp. nov. and Protosuberites sp. 'Panama' from the Eastern Pacific Ocean. The genetic distances based on COI sequences between all compared Protosuberites species were always higher than 2%, a value sufficient to confirm that P. mereui sp. nov. is a distinct species within the genus. Morphological and genetic analyses confirm unanimously P. mereui sp. nov. as a new species. Our results contribute to the assessment of biodiversity in anchialine/estuarine caves and increase data on sponge adaptive strategies in these extreme ecosystems.

A new species of Agelas from the Zanzibar Archipelago, western Indian Ocean (Porifera, Demospongiae).

A new sponge species (Demospongiae: Agelasida: Agelasidae) is described from the eastern coast of Unguja Island in the Zanzibar Archipelago. Agelas sansibarica sp. n. is compared to all other Agelas species described so far. The new species differs from its congeners mainly in its three categories of verticillate spicules (acanthostyles, acanthostrongyles, and acanthoxeas) and their sizes. Acanthostrongyles, well represented in the spicular complement, are an exclusive trait of the new species widening the morphological range of the genus. Summarizing on spicular complement and spicular morphotraits of 36 species belonging to the genus Agelas: i) 32 species show only acanthostyles from Indo-Pacific (n = 14), Atlantic (n = 17), and Mediterranean (n = 1); ii) three Indo-Pacific species show acanthostyles and acanthoxeas; iii) one species Agelas sansibarica sp. n. from the western Indian Ocean is characterised by the unique trait of three categories of verticillate spicules (acanthostyles, acanthostrongyles and acanthoxeas). A key for the Indo-Pacific species is supplied together with short descriptions, illustrations, and geographic range; literature on chemical bioprospecting of the genus Agelas is also provided.

Biodiversity in South East Asia: an overview of freshwater sponges (Porifera: Demospongiae: Spongillina)

Despite the fact that South East (SE) Asia is considered as a biodiversity hotspot, knowledge of sessile invertebrates such as freshwater sponges (Porifera: Haplosclerida: Spongillina) in this region is poor and scarcely reported. For this synopsis, diversity and distribution of SE Asian inland water sponges is reported on the basis of available literature and a recent biodiversity assessment of the Lower Mekong basin. A diagnostic key of families/genera from SE Asia is provided together with Light Microscopy and Scanning Electron Microscopy protocols to prepare the basic spicular complement for taxonomic identification. So far, SE Asian freshwater sponges consist of widespread and/or endemic species belonging to the families Metaniidae, Potamolepidae, and Spongillidae. The highest diversity is recorded from Indonesia, Philippines, Thailand, and Myanmar, respectively. Data from the other countries are necessary for our understanding of their diversity and distribution. Biodiversity in SE Asia is strongly underestimated, as indicated by recent new records and the discovery of new species of freshwater sponges in Thailand. Further investigations should reveal higher values of taxonomic richness, highlighting biogeographic patterns at the family/genus/species levels. A cooperative network involving Thai, Laotian and Italian researchers, was set up to contribute and fulfil knowledge on taxonomy, ecology and biotechnological potentialities of these neglected filter feeders, playing a key role in water purification and biomass production in both lentic and lotic ecosystems in the tropics.

New species of excavating sponges (Porifera: Demospongiae) on coral reefs from the Mexican Pacific Ocean

Three new species of coral reef boring sponges were found in remote coral reefs from Revillagigedo Island, an archipelago that is 386 km from the continent.Cliona medinaesp. nov. is a sponge with orange-yellow papillae characterized by short almost straight spirasters.Cliona tropicalissp. nov., is a yellow papillate sponge with a spicule complement similar to the species included in theCliona viridiscomplex. However, the new species differs from the rest of the species mainly in its external morphology and by differences in the size and shape of spicules.Thoosa purpureasp. nov. is characterized by its purple colour, and the spicular complement formed by tylostyles, two amphiaster categories, bi- tri- and tetra-radiate oxyasters and smooth or microspined centrotylote oxeas. In addition,Cliothosa tylostrongylatasp. nov. is also described from coral reefs from the southern Mexican Pacific Ocean. This is a light red species, with tylostyles and tylostrongyles as megascleres and ramose and nodulose amphiasters as microscleres. The four species were found exclusively excavating skeletons of live or dead corals of the genusPocillopora. This study increases the number of boring sponges known from the Mexican Pacific Ocean to 22 species and it is the first study on marine sponge fauna from the Revillagigedo archipelago.

A new species ofTriptolemma(Porifera: Pachastrellidae) from the Pacific Ocean with a revision of the genus

A new species,T. strongylatasp. nov. is described on the basis of material collected from the Pacific Ocean. The new species is characterized by the presence of sinuous strongyles. Moreover the incomplete description ofT. simplex(Sarà, 1959) is implemented on the basis of new abundant material allowing, for the first time, the complete description of the skeleton of aTriptolemmaspecies and the detecting of the presence of monaxonic spicules in the spicular complement of the genus. The skeleton is composed of a thick crust of disorderly arranged mesotriaenes and scattered microscleres, supported by diverging spicule tracts formed by oxeas towards the surface. Both species were recorded associated to boring sponges(SpiroxyaandCliona)in excavations of the calcareous scleraxis of precious corals or in organogenic concretions. In the cavities where the tissue ofTriptolemmawas recorded the wall of the excavation partially lost its typical pattern characterized by ovoid scars and became irregularly eroded. Our hypothesis is thatTriptolemmainsinuates inside the erosions produced by other sponges and it is able to enlarge them by an etching mechanism based on chemical dissolution only.

Sponges boring into precious corals: an overview with description of a new species of Alectona (Demospongiae, Alectonidae) and a worldwide identification key for the genus

AbstractPrecious corals represent peculiar substrata for several species of boring sponges that exploit their carbonatic scleraxis, strongly decreasing their commercial value. Here we describe a new species of the genus Alectona from Japan recorded in a colony of Paracorallium japonicum (Kishinouye, 1903). The spicular complement of the new species consists of diactinal spicules covered by mushroom‐like tubercles, often modified into styloid forms, and fusiform amphiasters with two or sometimes four verticils, each generally made up of six short tubercled rays. A complete survey of the literature on boring sponges recorded in precious corals in the Mediterranean Sea and Pacific Ocean indicates that the species of the family Alectonidae are the most strictly associated to this kind of substratum. Their world distribution, in fact, partially or totally overlap that of their coral hosts.

A new species of Thoosa (Demospongiae, Hadromerida) excavating precious coral Corallium sp. from Midway

A new species of Thoosa, T. midwayi n. sp., excavating the scleraxis of Corallium sp. and collected in the Midway Islands, is described on the basis of its spicular complement characterised by two types of amphiasters. The new species differs from the closest species, T. amphiasterina Topsent, in the shape and size of the amphiasters. Although still at a very initial stage, the study of the sponges boring into the scleraxis of Pacific precious corals suggests that the boring assemblage varies according to the different coral populations probably due to the different species of the genus Corallium present in the Pacific area and to the geographical isolation of the precious coral banks.

Symbiosis of Mycale (Mycale) vansoesti sp. nov. (Porifera, Demospongiae) with a coralline alga from North Sulawesi (Indonesia)

Abstract. The symbiotic association between the new sponge species Mycale vansoesti and the coralline alga Amphiroa sp. from the Bunaken Marine Park (North Sulawesi, Indonesia) is described. The alga completely pervades the sponge. The color of the sponge ectosome is white, both on the external surface and on the atrial wall, but where the alga is present the sponge takes on the light pink color of the alga. The sponge spicular complement is characterized by mycalostyles, anisochelae of two types, sigmas (often “C” shaped), and extremely abundant toxas organized in bundles forming toxadragma. In the association, the sponge shows very low silicate value, and consequently the alga represents the main skeleton of the sponge. On the other hand, the sponge affects the morphology of the alga, leading to a cylindrical shape, with thalli running parallel to the sponge surface. This association seems to be obligate for the sponge, as we found no sponges of this species living in isolation.

Redescription of Alectona verticillata (Johnson) (Porifera, Alectonidae) boring into Japanese precious coral

The boring sponge Alectona (Nisella) verticillata (Johnson, 1899) was recorded, for the first time after the description, in a colony of Corallium elatius collected in the south of the Ryukyu Islands (Japan Sea). The material recorded allowed a redescription of the species based on the SEM analyses of its spicular complement. Alectona verticillata is the only species of the genus characterised by three kinds of amphiasters and by the lack of the large, spiny or tubercolate diactines, considered typical of the genus. Its distribution recalls the Tethyan distribution of the genus Corallium, indicating a high specificity of boring sponges for their substrata.

Delectona madreporica n. sp. (Porifera, Demospongiae) boring the corallites of some scleractinians from the Ligurian Sea

A new species of sponge, belonging to the genus Delectona, has been observed in the corallites of Leptopsammia pruvoti and Madracis pharensis living in semidark caves on the Portofino Promontory (Ligurian Sea). The species, here described as Delectona madreporica, has a spicular complement composed of rhabds, which are very irregular in shape and size and derived from fusiform amphiasters, by oxyasters derived from slender amphiasters and by toxiform, sometimes centrotylote, microxeas. The taxonomic position of this species is discussed.

Delectona ciconiaesp. nov. (Porifera, Demospongiae) boring in the scleraxis ofCorallium rubrum

A new species of sponge, belonging to the genusDelectona, has been observed in the scleraxis ofCorallium rubrumfrom three Mediterranean banks (Alboran, Elba Island and Bosa Marina). The species, described here as Delecfonsciconiae, shows a spicular complement composed of spiny rhabds, very irregular in shape and size, whose derivation from amphiasters has been suggested; toxiform centrotylote oxeas; slender, irregular amphiasters and subcircular or ovoid rough discs. The taxonomic position of this species, within the Clionidae, has been discussed.