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Adaptive morpho-traits, taxonomy and biogeography of the genus Metania Gray, 1867 (Porifera: Spongillina: Metaniidae) with the description of a new species from Madagascar
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Abstract
A comparative analysis of gemmular architecture adaptive morpho-traits at family level is reported for Metaniidae together
with the discovery and description of a new species from the River Mangoky (High Plateau), Madagascar. The new
Malagasy species, ascribed to Metania for diagnostic traits of the skeleton and the gemmular architecture, differs from all
the other known species of the genus in its unique combination of diagnostic traits. Metania madagascariensis sp. nov. is
characterised by encrusting growth form, conulose surface, specialized ectosomal skeleton, alveolate-reticulate choanosomal
skeleton, two types of megascleres as smooth oxeas (α) and acanthoxeas (β) ornamented with spines and/or tubercles,
one type of microsclere as acanthoxeas with dense spines/tubercles bearing rosettes of microspines at tips; gemmules
with or without cage of megascleres and frequently surrounded by microscleres; gemmular theca trilayered with pneumatic
layer of fibrous spongin, boletiform (trumpet-like) gemmuloscleres with proximal true rotule large, smooth and with
irregular blunt margins, and distal knob-like pseudorotule notably smaller, with a few hooks at the margins. M. madagascariensis
belongs to the Afrotropical species group of Metania. Identification keys and an annotated checklist at global
level are also provided together with a species-level discussion of Metania focusing on morphology, taxonomy, nomenclature
and biogeography.A comparative analysis of gemmular architecture adaptive morpho-traits at family level is reported for Metaniidae together
with the discovery and description of a new species from the River Mangoky (High Plateau), Madagascar. The new
Malagasy species, ascribed to Metania for diagnostic traits of the skeleton and the gemmular architecture, differs from all
the other known species of the genus in its unique combination of diagnostic traits. Metania madagascariensis sp. nov. is
characterised by encrusting growth form, conulose surface, specialized ectosomal skeleton, alveolate-reticulate choanosomal
skeleton, two types of megascleres as smooth oxeas (α) and acanthoxeas (β) ornamented with spines and/or tubercles,
one type of microsclere as acanthoxeas with dense spines/tubercles bearing rosettes of microspines at tips; gemmules
with or without cage of megascleres and frequently surrounded by microscleres; gemmular theca trilayered with pneumatic
layer of fibrous spongin, boletiform (trumpet-like) gemmuloscleres with proximal true rotule large, smooth and with
irregular blunt margins, and distal knob-like pseudorotule notably smaller, with a few hooks at the margins. M. madagascariensis
belongs to the Afrotropical species group of Metania. Identification keys and an annotated checklist at global
level are also provided together with a species-level discussion of Metania focusing on morphology, taxonomy, nomenclature
and biogeography
Adaptive morpho-traits, taxonomy and biogeography of Metania Gray, 1867 (Porifera: Spongillina: Metaniidae) with the description of a new species from Madagascar
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Contribution to the freshwater biodiversity assessment of Sardinian caves: planarians as model taxon.
No full textContribution to the assessment and conservation of biodiversity: inventory of some model taxa from Sardinian caves
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