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1.
Sci Rep ; 9(1): 7989, 2019 05 29.
Artículo en Inglés | MEDLINE | ID: mdl-31142811

RESUMEN

Macrodasyida (phylum Gastrotricha) comprises 365 species distributed across 34 genera and 10 families. However, current classification is under revision due to the contradictory results of molecular and morphological cladistic analyses. Studies aimed at bridging the gaps took advantage of supplementary assessments of poorly known species and particularly from observations of new taxa showing original traits that could help to identify plesiomorphic character states in these anatomically diverse micrometazoa. We follow this path by describing three new interesting macrodasyidan species respectively from Italy, Brazil and Sweden. In many respects, the new species resemble most closely species of the genus Macrodasys; however, details of the external morphology, in combination with the different lay-out of the reproductive system and the tiny spermatozoa lacking a visible flagellum, suggest they belong to a new genus, possibly in the family Macrodasyidae. These hypotheses are supported by the phylogenetic relationships of 47 taxa inferred from analyses of the 18S rRNA gene, which found the new species clustering with Thaidasys tongiorgii in a subset of a larger clade containing Macrodasys. Accordingly, the establishment of the following taxa is proposed: Kryptodasys gen. nov., K. marcocurinii sp. nov., K. carlosrochai sp. nov. and K. ulfjondeliusi sp. nov.


Asunto(s)
Organismos Acuáticos/genética , Clasificación , Filogenia , ARN Ribosómico 18S/genética , Animales , Organismos Acuáticos/clasificación , Brasil , Análisis de Datos , Italia , Suecia
2.
Zookeys ; (734): 105-119, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29674856

RESUMEN

The study falls within the framework of a wider research programme aimed at investigating the gastrotrich diversity of the Tropical North-Western Atlantic (TNWA). A new macrodasyidan gastrotrich is described from fine-medium sand collected at Duncans Bay, Jamaica. The description is based on observations carried out on living specimens using differential interference contrast microscopy. Paraturbanella xaymacanasp. n., the third gastrotrich taxon reported from Jamaica, is a mid-sized species, up to 564 µm long, with a feeble peribuccal swelling. The most obvious autapomorphic traits pertain to the testes and the male pore, both of which are located approximately at mid body, rather than at- or near the pharyngo-intestinal junction as occur in the other species of the genus. Additional differences with congeners are discussed and a key to the Paraturbanella species is provided, in the hope it will be useful to both gastrotrich experts and marine ecologists who discover these microscopic metazoans during their research.

3.
Zookeys ; (289): 13-24, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23794850

RESUMEN

A new species of marine Gastrotricha from Brazil is described and discussed. Ptychostomella lamelliphora sp. n. is one of the several new taxa that were found during an extensive survey of the gastrotrich fauna carried out in 2002 and 2003 along the coastline of the State of São Paulo. The new species is unique in that it possesses cuticular ornamentations in the form of plate-like structures (scales) along the lateral borders of the body and two massive clusters of densely packed adhesive tubes on the ventral surface, near the ano-genital opening. Both these features appear to be adaptations to challenge the high energy waters that characterize the species' microhabitat: the coarse sublittoral sand in the channel between the mainland and the largest island in the State, Ihlabela. Additionally, a key to the described Ptychostomella species of the world is provided.

4.
Zookeys ; (223): 39-51, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23166459

RESUMEN

In previous papers, faunistic and preliminary taxonomic data on the gastrotrich communities along the coastline of the Brazilian states of São Paulo and Rio de Janeiro were reported; among the over 40 records, the occurrence of several species new to science was highlighted. One of such new taxa is described here based on observation carried out on living and SEM prepared specimens. Pseudostomella dolichopodasp. n. (Gastrotricha: Thaumastodermatidae) is the only species in the genus that attains 420 µm in total length, is covered by pentancres and possesses, among others, caudal pedicles up to 45 µm in length. Additional differences with co-generic taxa characterized by a pentancrous covering are discussed. Furthermore, a key to the described Pseudostomella species of the world based on easily discernible traits, visible in both living and formalin-fixed specimens, is provided.

5.
J Dairy Sci ; 80(11): 3023-9, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9406096

RESUMEN

Test day models were used to estimate the lactation curves for Valle del Belice ewes and to study the main environmental effects on milk yield and on percentage of fat and protein. Environmental effects were treated as fixed. A random effect was associated with each lactation to evaluate the mean correlation among all test day records of an individual ewe. Lactation curves were constructed by adding solutions for classes of either days in milk nested within parity or days in milk nested within season of lambing to appropriate general means. Parity primarily affected the lactation curve for milk yield, which was lower and flatter for first lambing ewes; effects on fat and protein were smaller. Season of lambing affected all traits. Seasonal productivity had the greatest effect on milk composition, resulting in an imbalance between fat and protein percentages. Flock and feed supplementation affected only the lactation curve for milk yield. The lactation curve of Valle del Belice ewes stood at a relatively high level. However, the presence of notable, perturbative effects (environmental and random variation) on milk yield and composition suggests that management is unable to meet the requirements of ewes consistently.


Asunto(s)
Lactancia , Lípidos/análisis , Proteínas de la Leche/análisis , Leche/química , Ovinos/fisiología , Alimentación Animal , Animales , Femenino , Modelos Biológicos , Paridad , Embarazo , Estaciones del Año
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