1,721,030 research outputs found
Antygomonas caeciliae, a new kinorhynch from the Mediterranean Sea, with report of mitochondrial genetic data for the phylum
No full textKinorhyncha is a phylum of microscopic marine metazoans living from intertidal to abyssal depths. More than 200 species are known; nevertheless, recent studies have pointed out that most of this group's diversity has not been revealed. A survey of the peculiar Meloria Shoals seabed (Ligurian Sea, Italy) led to the discovery of a new kinorhynch named Antygomonas caeciliae sp. nov. A cytochrome c oxidase subunit I (COI) mtDNA gene is reported for the new species; hence, a morphological and molecular approach is used for the description of this new taxon, and a comparison with related species is proposed, including a key to the species of Antygomonas. Some additional COI sequences are reported for other taxa of the phylum, with the aim of developing molecular tools which will be useful for species identification, particularly when dealing with juvenile stages
Investigation of echinoderid kinorhynchs described 90 years ago: redescription of Echinoderes capitatus (Zelinka, 1928) and Echinoderes ferrugineus Zelinka, 1928
Full text linkThe two kinorhynch species Echinoderes capitatus (Zelinka, 1928) and Echinoderes ferrugineus Zelinka,
1928 are redescribed herein, based on specimens collected at different Mediterranean locations. Echinoderes
capitatus is characterized by the presence of middorsal acicular spine on segment 4 and lateroventral
acicular spines on segments 6e9; at least three pairs of tubes on segment 2 (subdorsal,
midlateral, and ventrolateral); subdorsal tubes on segment 8; laterodorsal tubes on segment 10; lateral
accessory tubes on segments 5 and 8; subdorsal sensory spots on segments 1 and 3e11; and ventromedial
sensory spots on segments 2 and 5e7, often additionally on segment 8; occurrence of subdorsal
tubes on segments 6 and 7, laterodorsal tubes on segment 2, midlateral tubes on segments 7 and 8, and
ventromedial tubes on segment 8 showing intraspecific variation; and the absence of the type-2 gland
cell outlets. The pattern of the additional tubes is relatively well-preserved within a population but
differs among populations. Echinoderes ferrugineus is characterized by the presence of middorsal acicular
spines on segment 4e8; lateroventral acicular spines on segments 6e9; lateral accessory tubes on
segment 5; type-2 gland cell outlets in subdorsal, laterodorsal, sublateral, and ventrolateral position on
segment 2, subdorsal and midlateral position on segment 4, midlateral position on segment 5, and
midlateral position on segment 8; long lateral terminal spines (ca. 140e180 mm, 45e63% of trunk length).
Comments are provided on the intraspecific variation in tube pattern in E. capitatus, and its potential
importance in a speciation and evolutionary context
Analysis of the macrozoobenthic community of a perifluvial buffer of the Secchia river (Reggio Emilia, Emilia-Romagna)
No full textIn aprile 2018 è stato intrapreso uno studio biologico dell’area perifluviale di un tratto collinare del
Fiume Secchia in località Tressano di Castellarano (Reggio Emilia). La prima indagine si è concentrata
sulla comunità macrozoobentonica che popola uno stagno situato nel cuore di quest’area. I
macroinvertebrati bentonici sono considerati ottimi bioindicatori della qualità dell’ambiente acquatico;
per questo motivo sono state valutate sia la loro ricchezza specifica, sia l’abbondanza. Oltre alla
determinazione morfologica dei macroinvertebrati, i dati quali-quantitativi sono stati sottoposti ad
analisi multivariate. Inoltre, nel corso dello studio sono stati registrati i parametri chimico-fisici delle
acque. I dati preliminari hanno consentito di ottenere un quadro qualitativo dello stagno, funzionale
a futuri progetti di valorizzazione ambientale.Analysis of the macrozoobenthic community within a perifluvial buffer zone of the River Secchia
(northern Italy). In April 2018, a biological study of a foothill perifluvial buffer zone of the River
Secchia at Tressano di Castellarano (province of Reggio Emilia) was carried out. First investigations
focused on the macrozoobenthic community of a pond located within the study area. Benthic
macroinvertebrates are considered excellent bioindicators of the quality of the aquatic environment:
so, both the richness and abundance of species were assessed. In addition to the morphological
determination of macroinvertebrates, quali-quantitative data underwent multivariate analyses.
Finally, water chemical-physical parameters were recorded during the study. The preliminary data
allowed a qualitative picture of the pond to be obtained, which can be useful for future environmental
improvement projects
The soil fauna of a perifluvial buffer of the Secchia river (Reggio Emilia, Emilia-Romagna)
No full textIn aprile 2018 è stato intrapreso uno studio biologico dell’area perifluviale di un tratto collinare del
Fiume Secchia in località Tressano di Castellarano (Reggio Emilia). La prima indagine si è concentrata
sulla comunità macrozoobentonica che popola uno stagno situato nel cuore di quest’area. I
macroinvertebrati bentonici sono considerati ottimi bioindicatori della qualità dell’ambiente acquatico;
per questo motivo sono state valutate sia la loro ricchezza specifica, sia l’abbondanza. Oltre alla
determinazione morfologica dei macroinvertebrati, i dati quali-quantitativi sono stati sottoposti ad
analisi multivariate. Inoltre, nel corso dello studio sono stati registrati i parametri chimico-fisici delle
acque. I dati preliminari hanno consentito di ottenere un quadro qualitativo dello stagno, funzionale
a futuri progetti di valorizzazione ambientale.Analysis of the macrozoobenthic community within a perifluvial buffer zone of the River Secchia
(northern Italy). In April 2018, a biological study of a foothill perifluvial buffer zone of the River
Secchia at Tressano di Castellarano (province of Reggio Emilia) was carried out. First investigations
focused on the macrozoobenthic community of a pond located within the study area. Benthic
macroinvertebrates are considered excellent bioindicators of the quality of the aquatic environment:
so, both the richness and abundance of species were assessed. In addition to the morphological
determination of macroinvertebrates, quali-quantitative data underwent multivariate analyses.
Finally, water chemical-physical parameters were recorded during the study. The preliminary data
allowed a qualitative picture of the pond to be obtained, which can be useful for future environmental
improvement projects
Una nuova specie di Antygomonas (Kinorhyncha: Cyclorhagida) dalla costa toscana
No full textA new species of the rare genus Antygomonas (Kinorhyncha) is reported from the Meloria shoals (Leghorn, Italy). While the finding represents the first record of this genus in Italian waters, the high number of specimens recovered will contribute to the development of molecular tools useful for species identification, a difficult task especially when dealing with juveniles
Italian Kinorhyncha: status of Biodiversity and distribution
No full textKinorhyncha are microscopic marine metazoans constituting a phylum that comprises more than 250 described species living from intertidal to abyssal depths. Studies on the Italian kinorhynch fauna have been rather erratic in space and time, with most records originating in the first decades of the XX century from the Gulfs of Naples and Trieste. Here, we provide information based on a careful taxonomic revision of published material but mainly on new data from recent surveys carried out in areas of Ligurian Sea (4), Tyrrhenian Sea (8), Ionian Sea (1), and Adriatic Sea (3 localities). New data derives from qualitative as well as from quantitative samples. During our surveys, 30 species in 11 genera and 6 families were recorded. Of the species found, 16 appear new to science or new to the national fauna, while 14 were previously known from Italian waters. Particularly relevant is the finding of two new species of the rare genus Condyloderes, unreported before from the Mediterranean Sea. The new faunistic information, along with novelties in the systematics of the phylum, prompted us to prepare an updated checklist, which brings to 37 species, 11 genera and 6 families the number of kinorhynch taxa known from the Italian seas. The most speciose genus is Echinoderes, followed by Pycnophyes, with 11 and 10 species, respectively. The former genus includes the species showing the highest abundances, E. capitatus, with recorded densities up to 184 ind./10 cm2, while the latter includes the most common species P. communis, found in 12 localities from the Ligurian, Tyrrhenian, and Adriatic Seas. Concerning distribution, it appears that five species only can be considered ubiquitous in the four Italian sea basins, whereas the other species seem to be restricted to one or two basins. However, many sectors of the national waters remain unexplored. Further research should concentrate especially on peculiar habitats, such as coarse biogenic sediments, submarine caves, and lagoons, which our studies indicated as biodiversity hotspots for the ‘mud dragons’
Un aberrante nuovo genere di Chinorinchi, con analisi della sua posizione filogenetica e delle relazioni interne al phylum
No full textIl phylum Kinorhyncha è costituito da circa 200 specie meiobentoniche rinvenute nei mari di tutto il mondo. La sistematica del gruppo è fondata unicamente su caratteristiche morfologiche e poche sono state finora le indagini filogenetiche, tra le quali una sola, preliminare, ha utilizzato dati di genetica molecolare. La recente scoperta, in sabbie provenienti dal Brasile, di una specie di particolare interesse, poiché non ascrivibile a nessun genere noto, ha fornito lo spunto per intraprendere uno studio approfondito sulle relazioni interne del phylum. Gli esemplari brasiliani sono caratterizzati da un tronco molto flessibile e circolare in sezione trasversa. I segmenti 1, 2 e 11 sono formati da anelli cuticolari interi, mentre i segmenti dal 3 al 10 presentano placche articolate ventralmente. Il collo, privo di placidi, ha l’aspetto di un segmento addizionale. Il segmento terminale porta una spina mediana dorsale e due coppie di spine laterali. Poiché le caratteristiche anatomiche rendono difficile la collocazione del nuovo genere nell'ambito del phylum, le sue relazioni filogenetiche sono state indagate utilizzando come marker il gene nucleare 18S rRNA; nella ricerca sono state coinvolte altre specie raccolte durante studi paralleli. Complessivamente sono state analizzate le sequenze di 48 specie, appartenenti a 15 generi e 8 famiglie ripartite nei due ordini in cui il phylum viene suddiviso: Homalorhagida e Cyclorhagida. Le analisi, condotte con tre metodi diversi, Maximum Likelihood, Massima Parsimonia e Inferenza Bayesiana, evidenziano chiaramente che il nuovo genere è un homaloragide basale, sebbene le sue caratteristiche morfologiche sembrassero in prima istanza indicare affinità con il cicloragide Cateria. Le topologie rivelano inoltre importanti differenze rispetto alla sistematica tradizionale, di fatto indicando come non monofiletici i due ordini oggi riconosciuti. Le novità più eclatanti riguardano l’inclusione nel clade degli Homalorhagida della famiglia Dracoderidae, attualmente affiliata ai Cycloragida, e alcune alleanze tra taxa anch’essi inclusi al momento nell’ordine Cycloragida. I risultati ottenuti, nel dimostrare che molti aspetti dello scenario evolutivo corrente sono da riconsiderarsi, suggeriscono una rivalutazione in chiave evoluzionistica di alcuni caratteri morfologici finora negletti negli studi filogenetici
A NEW SPECIES OF ANTYGOMONAS (KINORHYNCHA: CYCLORHAGIDA) FROM THE TUSCANY COAST
No full textA new species of the rare genus Antygomonas (Kinorhyncha) is reported from the Meloria shoals (Leghorn, Italy). While the finding represents the first record of this genus in Italian waters, the high number of specimens recovered will contribute to the development of molecular tools useful for species identification, a difficult task especially when dealing with juveniles
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