Lithistid Sponges from the Norfolk Rise. Recent and Mesozoic Genera

Lévi, Claude

doi:10.1007/978-3-642-75656-6_7

Cited by 34 publications

(36 citation statements)

References 1 publication

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“…In these articulate zygoses, the perfect fitting of the zygomatic plates around the spine-like structures of adjacent desmas suggests that growth of the spinelike structures has to be finished before the zygomatic plates contact with them. From morphological observations, it has been postulated that the silicification process in desmas has two phases (L6vi, 1991;Uriz & Maldonadol 1995). The first phase, where silicification is guided by the axial filament, would yield crepis of very constant shape.…”

Section: Remarkable Featuresmentioning

confidence: 99%

Skeletal morphology of two controversial Poecilosclerid genera (Porifera, Demospongiae):Discorhabdella andCrambe

Maldonado

Uriz

1996

Helgolander Meeresunters

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The genera Discorhabdella and Crambe are characterized by bearing uncommon spicule types, i.e. pseudoastrose acanthostyles and sphaeroclones, respectively. They have traditionally been considered to be unrelated taxa, but the present reexamination made evident that an important amount of skeletal features are shared by both. Some of these morphological features, such as the ornamentation on the point of the ectosomal subtylostyles, are reported for the first time. The study also revealed that a tuberose nature of the tyles of the main choanosomal megascleres could be a common ancestral condition in both genera. The morphology of the multi-toothed anchorate chelae showed a gradual transition across the species, suggesting that the morphological diversity in chelae was generated in these genera through a "palmate-anchorate-arcuate" evolutionary sequence. However, the forward or backward direction of this sequence remained unclear from the available evidence. Important levels of skeletal variability were found to affect many of the skeletal characters, especially in the genus Crambe. In some cases, this variabihty transgressed the limits theoretically defining a species, making evident that the traditional procedure just based on comparison of the skeletons becomes unreliable when tackling the taxonomy of these genera. Most of the skeletal variability seemed to correspond to genetic polymorphisms, except in the case of C. acuata. In this taxon, the skeletal variability could be a result of the existence of a cryptic species, originated by a misconceived synonymy between C. acuata and C. chelastra.Besides the skeletal variability, the obscure taxonomic meaning of many skeletal features favored the existence of conflicting taxonomic proposals for the suprageneric location of these genera, depending on the author's criteria. This study made evident that any subsequent attempt of phylogenetic inference should be based on an unweighted analysis of the available skeletal information.

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Section: Remarkable Featuresmentioning

confidence: 99%

Skeletal morphology of two controversial Poecilosclerid genera (Porifera, Demospongiae):Discorhabdella andCrambe

Maldonado

Uriz

1996

Helgolander Meeresunters

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“…Nine species belonging to 9 genera of 6 families have been until now recorded in the Mediterranean Sea (Appendix 1) (Topsent 1892a(Topsent , 1893(Topsent , 1925Vacelet 1960Vacelet , 1969Pouliquen 1969Pouliquen , 1972Pulitzer-Finali 1970Pansini 1992Pansini , 1995Boury-Esnault et al 1994;Magnino et al 1999;Pansini and Longo, 2003;Perez et al 2004;Longo et al 2005;Manconi et al 2006;Zibrowius and Taviani 2005). Th e taxonomic richness appears to be notably higher in the tropics (Lévi 1991;Pisera and Lévi 2002;Schlacher-Hoenlinger et al 2005) whereas the low values in the Mediterranean may be explained by the occurrence of extinction phenomena due to harsh environmental/climatic changes during the history of this basin (e.g. cooling phases in Plio-Pleistocene time, see Wiedenmayr 1994:107).…”

Section: Introductionmentioning

confidence: 99%

Rare sponges from marine caves: discovery of Neophrissospongia nana nov. sp. (Demospongiae, Corallistidae) from Sardinia with an annotated checklist of Mediterranean lithistids

Manconi¹,

Serusi²

2008

496

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A new record of lithistid demosponges is reported from a western Sardinian karstic cave. Th e new specimen matches the trait of the genus Neophrissospongia (Corallistidae) for an ectosomal skeleton of radial dichotriaenes, a choanosomal skeleton as a network of dicranoclone desmas, and streptaster/amphiaster microscleres with short spiny rays bearing blunt tips. Th e cave-dwelling N. nana nov. sp. diverges from the other species of the genus in diagnostic characters such as the large irregular plate-like growth form, the topographic distribution of inhalant and exhalant apertures, and a smaller size of all spicular types. Moreover it displays an additional rare second type of dichotriaenes with smooth cladomes, shared with other genera of Corallistidae but never reported before for the genus Neophrissospongia. In addition N. nana nov. sp. bears stylelike sub-ectosomal spicules shared with N. microstylifer from deep water of New Caledonia. As for the latter trait, a present in-depth analysis of N. nolitangere from the Atlantic Ocean contrasts with previous historical records reporting monaxial spicules as oxeas/anisoxeas. Th e diagnosis of the genus Neophrissospongia is therefore emended for the growth form and for the micro-traits of dichotriaenes and monaxial sub-ectosomal spicules. Morphological data indicate that the new species is allied to N. nolitangere and N. microstylifer from Eastern Atlantic and New Caledonian deep water, respectively, and its record confi rms the highly disjunct geographic range of the genus Neophrissospongia in the Lusitanian-Macaronesian-Mediterranean area and the western Pacifi c Ocean supporting the relic condition of the genus in the Mediterranean Sea. Th is discovery stresses the key status of Mediterranean palaeoendemics as possible remnants of an ancient Tethyan fauna and focuses the need to plan conservation measures for these rare cave-dwelling sponges.

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“…In contrast, hexactinellid sponges, of which rare spicules also occur in the studied turbiditic material, are commonly found in deep ocean and cold-water habitats (e.g., Rice et al 1990, Lévi 1991; however, they are also present in shallow and warm environments (e.g., Gammon et al 2000) but usually under special conditions (e.g., Whitney et al 2005). It should be stressed that the main controlling factor in the distribution of lithistid versus hexactinellid sponges in geological records and present-day communities is not bathymetry but the predominant type of food availability and sedimentation rate (Pisera et al 1992, Pisera 1997, Krautter 1997, Duarte et al 2001.…”

Section: Depth Of Sponge Associationsmentioning

confidence: 95%

“…Recent demosponges are found mainly on the intrabasinal plateaus and shelves surrounding the continents at water depths from very shallow down to approximately 600 m (Lévi 1991). In contrast, hexactinellid sponges, of which rare spicules also occur in the studied turbiditic material, are commonly found in deep ocean and cold-water habitats (e.g., Rice et al 1990, Lévi 1991; however, they are also present in shallow and warm environments (e.g., Gammon et al 2000) but usually under special conditions (e.g., Whitney et al 2005).…”

Section: Depth Of Sponge Associationsmentioning

confidence: 99%

Sponge growth on the Cenomanian carbonate shelves of the Carpathian Basin: a record from spicule-rich turbidites

Bąk¹,

Górny²,

Bąk³

2015

Bull. Geosci.

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The composition and features of numerous bioclasts found in the sandy/silty fraction of turbidite layers in the Middle-Upper Cenomanian deep-water sediments of the Silesian Nappe in the Outer Carpathians, dominated by sponge spicules, suggest that they originated from the growth and destruction of sponge assemblages formed on shelves of the northern margin of the Silesian Basin. The morphological types of spicules, by comparison with fossil and living species, lead to their attribution predominantly to three orders: Lithistida, Hadromerida and Astrophorida. Sponges lived in association with other benthic fauna such as calcareous benthic foraminifers and echinoids. Many sponge spicules were calcified in their primary environment before their redeposition by turbiditic flows. Favourable conditions for development of sponge assemblages occurred during the Cenomanian transgressions, being related to balanced delivery of sediment particles trapped by sponges and waters enriched with nutrients. The amount of nutrients absorbed by sponges is related to the dissolved silica content that originated from two sources: 1) terrestrial chemical weathering on the low-gradient plains of the shelves and 2) opal grains, such as siliceous plankton, suspended in the water column during bloom periods forced by seasonal upwelling. •

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Lithistid Sponges from the Norfolk Rise. Recent and Mesozoic Genera

Cited by 34 publications

References 1 publication

Skeletal morphology of two controversial Poecilosclerid genera (Porifera, Demospongiae):Discorhabdella andCrambe

Skeletal morphology of two controversial Poecilosclerid genera (Porifera, Demospongiae):Discorhabdella andCrambe

Rare sponges from marine caves: discovery of Neophrissospongia nana nov. sp. (Demospongiae, Corallistidae) from Sardinia with an annotated checklist of Mediterranean lithistids

Sponge growth on the Cenomanian carbonate shelves of the Carpathian Basin: a record from spicule-rich turbidites

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