Search

Start Over Subject life history

21. Seasonal variations in somatic condition, hepatic and gonad activity of sand smelt Atherina boyeri (Teleostei, Atherinidae) in the Mar Menor coastal lagoon (SE Iberian Peninsula)

Creator:
Andreu-Soler, Asunción, Oliva-Paterna, Francisco J., and Torralva, Mar
Type:
article and TEXT
Subject:
condition residual index, hepatosomatic residual index, gonadosomatic residual index, and life history
Language:
English
Description:
Seasonal changes in somatic condition, hepatic and gonad activity, as well as their effects with age and sex were examined in Atherina boyeri from the Mar Menor coastal lagoon (SE Spain). Seasonal cycles of somatic condition, hepatic and gonad activity were similar in both sexes, consisting of three phases. Somatic condition increased during summer, remained constant from autumn to mid-spring and decreased from mid-spring to the beginning of summer, coinciding with reproduction. Hepatic activity remained constant from mid-summer to winter, increased sharply from winter to spring and decreased during the spawning period, which lasted 4–5 months (similar to other Mediterranean locations). These cycles suggest that the species is well adapted to local conditions, ensuring reproductive success without endangering individual survival.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

22. Taxonomy of European Eristalinus (Diptera: Syrphidae) based on larval morphology and molecular data

Creator:
Pérez-Banón, Celeste, Rojo, Santos, Stahls, Gunilla, and Marcos-García, Angeles
Type:
article, model:article, and TEXT
Subject:
Syrphidae, Eristalinus, immature stages, morphology, life history, molecular data, and Europe
Language:
English
Description:
The taxonomy of European Eristalinus syrphid flies is reviewed. New data on their life histories, biological notes and a key to species using pupal characters are provided. The larvae and puparia of Eristalinus taeniops (Wiedemann, 1818) and Eristalinus megacephalus (Rossi, 1794) are described for the first time, including new morphological characters of the thoracic respiratory process of all species. The morphology of the male genitalia of E. megacephalus is described and compared with that of E. taeniops. The results of our morphological studies of the male genitalia and molecular data (mitochondrial COI and nuclear 28S rDNA) do not support the traditional adult classification based on the patterning on the eyes (fasciate vs punctate). We present a phylogeny of the species based on molecular data. The molecular and morphological data indicate that the relationship between some species with punctate eyes and those with fasciate eyes may be closer than with other species with punctate eyes. Moreover the results of the molecular studies support two clades, which does not accord with the traditional arrangement of this group of Syrphidae. Accordingly we propose that the characters of male genitalia stated by Kanervo in 1938 (but subsequently largely ignored) for arranging the European species of the Eristalinus-Eristalodes-Lathyrophthalmus complex, are suitable for classifying these species.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

23. Tragopogon porrifolius × T. pratensis: the present state of an old hybrid population in Central Bohemia, the Czech Republic

Creator:
Krahulec, František, Kaplan, Zdeněk, and Novák, Jan
Type:
article and TEXT
Subject:
Asteraceae, chromosome numbers, distribution, DNA content, life history, morphology, and Tragopogon
Language:
English
Description:
A population of a hybrid between Tragopogon porrifolius and T. pratensis (T. ×mirabilis), which occurs in SW part of the town of Roudnice nad Labem, N part of Central Bohemia, was analysed with respect to its morphology, fertility, life history, ploidy level and DNA content. Both parental species vary relatively little morphologically; they are biennials (monocarpic perennials) and diploids. T. pratensis is a native species in the Czech Republic, T. porrifolius was cultivated there in the past. The hybrid plants are extremely morphologically variable, with variation ranges of some characters overlapping those of the parental species (e.g. ligules are often longer than involucral bracts, peduncles are often lanate). Only diploids were found within the hybrid population; however, they have substantially lower DNA content than both parents (18% lower than T. pratensis, 42% lower than T. porrifolius). The plants of the Roudnice hybrid population are polycarpic perennials in contrast to the monocarpic perennial (mostly biennial) parents. The distribution is described in detail; it shows that the hybrid plants are spreading and at present even occur outside the town. The long-persisting population of fertile diploid hybrid plants in Roudnice nad Labem is an alternative evolutionary pathway to that of the allotetraploid Tragopogon species known from North America.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/