Search results for "Systematics"
showing 10 items of 6702 documents
Phytochemical characterization and antioxidant activity of the aerial part extracts from two species of Matthiola wild in Sicily: Matthiola sinuata a…
2022
As part of a project aimed at investigating the specific and intraspecific taxa of Matthiola which grow spontaneously in Sicily (Italy), in this work our research has been focused on Matthiola tricuspidata and Matthiola sinuata. The phenolic and volatile compounds of the hydroalcoholic extracts from the aerial parts of the selected species have been characterized by HPLC-PDA/ESI-MS and SPME-GC/MS analyses. Moreover, the antioxidant capacity in vitro (1,1-diphenyl-2-picrylhydrazil (DPPH), reducing power and Fe2+ chelating activity assays) and the toxicity (Artemia salina lethality bioassay) of the extracts were investigated. The phytochemical analyses highlighted quite different phenolic and…
Diplopod hemocyanin sequence and the phylogenetic position of the Myriapoda
2001
Hemocyanins are copper-containing respiratory proteins of the Arthropoda that have so far been thoroughly investigated only in the Chelicerata and the Crustacea but have remained unstudied until now in the Myriapoda. Here we report the first sequence of a myriapod hemocyanin. The hemocyanin of Spirostreptus sp. (Diplopoda: Spirostreptidae) is composed of two distinct subunits that are arranged in a 6 x 6 native molecule. The cloned hemocyanin subunit cDNA codes of for a polypeptide of 653 amino acids (75.5 kDa) that includes a signal peptide of 18 amino acids. The sequence closely resembles that of the chelicerate hemocyanins. Molecular phylogenetic analyses reject with high statistical con…
Investigating Müllerian mimicry: predator learning and variation in prey defences
2006
Inexperienced predators are assumed to select for similarity of warning signals in aposematic species (Mullerian mimicry) when learning to avoid them. Recent theoretical work predicts that if co-mimic species have unequal defences, predators attack them according to their average unpalatability and mimicry may not be beneficial for the better defended co-mimic. In this study, we tested in a laboratory environment whether a uniform warning signal is superior to a variable one in promoting predator learning, and simultaneously whether co-mimics are preyed upon according to their average unpalatability. There was an interaction of signal variation and unpalatability but inexperienced birds did…
Honesty of agonistic signalling and effects of size and motivation asymmetry in contests
1999
Game theoretical models predict that the main function of fighting behaviour is to assess the relative fighting ability of opponents. The sequential assessment game has often been used to investigate contests, while honest signalling theory has received much less attention. With the wolf spider Hygrolycosa rubrofasciata we investigated whether male agonistic signalling can reveal honest information about fighting ability, and how size and motivation asymmetries affect male fighting behaviour. We also determined whether male–male competition affects the courtship behaviour of the males. We found that agonistic drumming activity is an honest indicator of male fighting ability, and that relati…
Silene crassiuscula (Caryophyllaceae), a new species from Sicily
2015
Silene crassiuscula,, a new species of S. sect. Dipterosperma, is described and illustrated from North-Western Sicily. It is an annual halophyte with succulent growing on carbonatic or calcarenitic rocks of coastal stands. From the morphological point of view , S. crassiuscula appears to be similar to the species belonging to the S. colorata group especially to S. nummica, from Sardinia, from which it differs in several features chiefly regarding the habit, leaves, inflorescences, floral pieces and seed micro-morphology. An analytical key of the taxa belonging to this section is also provided.
Spiralian phylogenomics supports the resurrection of Bryozoa comprising Ectoprocta and Entoprocta.
2007
Phylogenetic analyses based on 79 ribosomal proteins of 38 metazoans, partly derived from 6 new expressed sequence tag projects for Ectoprocta, Entoprocta, Sipuncula, Annelida, and Acanthocephala, indicate the monophyly of Bryozoa comprising Ectoprocta and Entoprocta, 2 taxa that have been separated for more than a century based on seemingly profound morphological differences. Our results also show that bryozoans are more closely related to Neotrochozoa, including molluscs and annelids, than to Syndermata, the latter comprising Rotifera and Acanthocephala. Furthermore, we find evidence for the position of Sipuncula within Annelida. These findings suggest that classical developmental and mor…
Effect of epidermal papillomatosis on survival of the freshwater fish Rutilus rutilus.
2004
Epidermal papillomatosis occurs in several marine and freshwater fish species. Previously, papillomatosis has been shown to induce mortality in juvenile carp. We studied the effect of epidermal papillomatosis on the survival of adult male roach Rutilus rutilus by caging naturally diseased, marked (by us) fish in the field. Within the constraints of the experimental design, there was no difference in survival between healthy, slightly diseased and heavily diseased fish. Therefore, we conclude that the possible effect of epidermal papillomatosis on the mortality of wild roach is relatively minor.
Quantification de révolution morphologique du crâne des Hominidés et hétérochronies
1998
Abstract Comparisons of adult skulls of various species of great apes, fossil hominids and modern humans in the sagittal, Francfort and ortho-sagittal planes reveal a series of three separate organisation plans: ‘Great Ape’, ‘Australopithecine’ and ‘Homo’, the latter including primitive men ( Homo ergaster-erectus-neandertalensis ) and modern humans ( Homo sapiens ). Morphological changes between these plans are quantified for the first time here by vector fields. This study confirms the existence of cranio-facial contraction, which occurs as a series of leaps. The juvenile morphology of the great ape skull is broadly preserved in adult Homo sapiens, suggesting that numerous heterochronies …
Influences of Relatedness, Food Deprivation, and Sex on Adult Behaviors in the Group-living Insect Forficula auricularia
2014
The evolution of group living is generally associated with the emergence of social behaviors that ensure fitness benefits to group members. However, the expression of these behaviors may depend on group composition, which can vary over time with respect to sex, starvation status, and relatedness. Here, we investigated (1) whether adults of the group-living European earwig, Forficula auricularia, show cooperative behaviors toward conspecifics and (2) whether sex, food availability, and relatedness shape the nature and frequency of these behaviors. We conducted a full-factorial experiment using 108 unisexual pairs of adults, in which we manipulated these three factors and video-recorded the e…
Chemosensory Receptors in the Larval Maxilla of Papilio hospiton
2022
Among the butterflies of the genus Papilio (Lepidoptera: Papilionidae), Papilio hospiton (Géné) has a geographical distribution limited to the Mediterranean islands of Sardinia (Italy) and Corsica (France). This is mainly due to the host range that includes only a few plant species of Apiaceae and Rutaceae growing on these islands. In a previous electrophysiological investigation conducted on the maxillary gustatory system of larvae of P. hospiton and its closely phylogenetically related species Papilio machaon, a significantly higher spike activity was shown for the gustatory neurons of lateral and medial styloconic sensilla in P. hospiton when bitter compounds were tested. This effect was…