scholarly journals The History of Sexual Dimorphism in Ostracoda (Arthropoda, Crustacea) Since the Palaeozoic

10.5772/55329 ◽  
2013 ◽  
Author(s):  
Hirokazu Ozawa
Keyword(s):  
Sexual Dimorphism ◽  
History Of

Sexual dimorphism, deformations, and epibionts of Phrynops tuberosus (Testudines, Chelidae)

2015 ◽  
Vol 65 (3-4) ◽  
pp. 311-320 ◽  
Author(s):  
João Fabrício Mota Rodrigues ◽  
José Roberto Feitosa Silva
Keyword(s):  
Sexual Dimorphism ◽  
Natural History ◽  
Tail Length ◽  
Condition Index ◽  
Head Width ◽  
Body Condition Index ◽  
Future Studies ◽  
History Of ◽  
One Year ◽  
Effective Conservation

Studies focusing on the natural history of species are essential for developing effective conservation measures and evaluating ecological hypotheses. To this end, we describe natural history data of the Cotinga River toadhead turtle, Phrynops tuberosus, in the Banabuiú River in Ceará, Brazil, and evaluated sexual dimorphism, epibionts, and mutilation effects. We hand-captured 134 individuals by snorkeling, over a period of one year, resulting in the capture of 94 males, 24 females, and 16 juveniles. Females had larger head width and body mass than males, while males had longer tail length. One quarter of the turtles captured had some sort of injury or deformation, most common injuries being missing claws, mutilations, and shell deformations. We found no difference in body condition index between mutilated and non-mutilated animals. Mollusks, insects, and leeches were found as epibionts on P. tuberosus and most of the captured turtles had extensive algal cover. Future studies should focus on understanding the effect of mutilations on animal fitness and reproductive success.

Life on the edge: the ecology and life history of the tropidurine iguanid lizard Uranoscodon superciliosum

1990 ◽  
Vol 68 (7) ◽  
pp. 1366-1373 ◽  
Author(s):  
Jeffrey M. Howland ◽  
Laurie J. Vitt ◽  
Pamela T. Lopez
Keyword(s):  
Life History ◽  
Social Interaction ◽  
Sexual Dimorphism ◽  
Small Diameter ◽  
Habitat Specialization ◽  
Large Size ◽  
Tropical Wet Forest ◽  
History Of ◽  
Forest Streams ◽  
Small Forest

An Amazonian population of the iguanid lizard Uranoscodon superciliosum was studied in lowland tropical wet forest in central Pará, Brazil. These nonheliothermic lizards are restricted to densely vegetated habitats near (often over) water, particularly riverbanks and small forest streams, where they utilize small-diameter perches and feed on a wide variety of invertebrates, apparently at the water's edge. They mature at moderate to large size at an age of about 1.5 years. Production of moderate-sized clutches of eggs is seasonal, and reproduction and fat storage both cycle in association with rainfall and flooding. Although they occur in fairly high densities, social interaction is uncommon and sexual dimorphism is not pronounced. The ecology and life history of this lizard seem to be strongly influenced by the unusual habitat specialization.

Some hydrozoans (Cnidaria) from Central Chile and the Strait of Magellan

Zootaxa ◽  
2012 ◽  
Vol 3296 (1) ◽  
pp. 19 ◽  
Author(s):  
HORIA R. GALEA ◽  
DIRK SCHORIES
Keyword(s):  
Life Cycle ◽  
Sexual Dimorphism ◽  
Intermediate Zone ◽  
Present Material ◽  
Central Chile ◽  
Strait Of Magellan ◽  
The Strait Of Magellan ◽  
History Of ◽  
Biogeographical Regions

This report supplements a series of earlier accounts on the hydrozoan fauna of Chile, and discusses 34 species of hydroidsand one hydromedusa. The available collection was gathered from three distinct biogeographical regions: the southernborder of the Peruvian Province around Punta de Choros, the southern Intermediate Zone around Corral, and the northernand southern parts of the Magellan Province, around Reloncaví Sound and in the Strait of Magellan, respectively. All thespecies are fully illustrated and, when necessary, data on the cnidome composition are provided. Six species, Haleciumannuliforme, Sertularella curvitheca, Sertularella mixta, Symplectoscyphus patagonicus, Halopteris plumosa, and Clytiareloncavia, are described as new. The gonothecae of Halecium fjordlandicum Galea, 2007, Symplectoscyphusmagellanicus (Marktanner-Turneretscher, 1890), and Campanularia hartlaubi (El Beshbeeshy, 2011) are described for thefirst time, while those of Kirchenpaueria curvata (Jäderholm, 1904) were rediscovered and are accurately redescribed.Morphological differences between C. hartlaubi and C. lennoxensis (Jäderholm, 1903), two species with similartrophosomes, are highlighted. Large, fertile specimens of Halecium pallens Jäderholm, 1904, as well as a female colonyof Hydractinia parvispina Hartlaub, 1905, allowed new redescriptions to be made. Due to insufficient taxonomicinformation on several species created more than a century ago, two Chilean records are doubtfully assigned toSertularella implexa (Allman, 1888) and Sertularella lagena Allman, 1876, respectively, the former represented by fertilespecimens, and thus allowing the first description of its gonothecae. The long history of the confused taxonomy of SouthAmerican "Symplectoscyphus subdichotomus (Kirchenpauer, 1884)" is now entirely settled. All the available records areconfidently assigned to the synonymy of Symplectoscyphus filiformis (Allman, 1888), whose sexual dimorphism ofgonothecae, first indicated by Totton (1930), is confirmed in light of the present material. Five species represent newrecords for the country: Staurocladia vallentini (Browne, 1902), Samuraia tabularasa Mangin, 1991, H. pallens,Sertularella blanconae El Beshbeeshy, 2011, and Symplectoscyphus paraglacialis El Beshbeeshy, 2011, the latter twobeing redescribed. Due to the scarcity of available material and the lack of gonophores of both sexes, six species ofEudendrium Ehrenberg, 1834 could be identified to genus only. Similarly, a species of Sertularella Gray, 1848 and twobelonging to Symplectoscyphus Marktanner-Turneretscher, 1890, are awaiting reliable identifications based on fertile specimens. A species of Clytia Lamouroux, 1812 could not be determined to species in the absence of life cycle studies.

Demodex antechini sp.nov. (Acari, Demodicidae) parasitic on Antechinus stuartii (Marsupialia)

Parasitology ◽  
1970 ◽  
Vol 60 (3) ◽  
pp. 425-429 ◽  
Author(s):  
W. B. Nutting ◽  
Gordon K. Sweatman
Keyword(s):  
Life Cycle ◽  
Sexual Dimorphism ◽  
Evolutionary History ◽  
Antechinus Stuartii ◽  
History Of ◽  
Early Origin

SUMMARYThe first marsupial demodicid, Demodex antechini, is described with notes on its life cycle, sexual dimorphism and pathology. This species is remarkably similar except for the marked sexual dimorphism, to demodicids of eutherian mammals. This suggests an early origin and a long evolutionary history of parallelism within the genus.Our thanks to Patricia Woolley, Waite Agricultural Institute, Glen Osmond, Australia, for the specimens used in preparing this paper. We would also like to thank Clifford Desch for the photography and the drawings. The work reported here was supported in part by NSF Grant (GB-3516).

The Tasmanian Whitebait, Lovettia seali (Johnston), and the Whitebait Fishery

1950 ◽  
Vol 1 (2) ◽  
pp. 155 ◽  
Author(s):  
M Blackburn
Keyword(s):  
Growth Rate ◽  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Incubation Period ◽  
Standard Length ◽  
Southern Population ◽  
History Of ◽  
One Year

The biology of the aplochitonid Lovettia seali (Johnston), which comprises over 95 per cent. of the Tasmanian whitebait catch, has been studied. Over 78,000 fish from 95 samples were sexed and measured, and 1,200 were classified as to maturity, pigmentation stages, and the presence or absence of food in the stomach. Vertebra counts were made for 1,200 specimens, and there were other observations upon smaller amounts of material. There are marked resemblances to other salmonoids in most points of the biology. There is conspicuous sexual dimorphism. The fish are anadromous and at their ascent are all mature or almost so, and all of the same age (one year by otoliths). After spawning begins there is progressive discoloration and emaciation, followed almost invariably by death. About 0.001 per cent. of the stock consists of two-year fish. The eggs are large compared with the size of fish (extremes of standard length in the adult stock are 33 and 70 mm.) and the incubation period is about three weeks. The larvae drift downstream to the sea. Sex ratio is highly variable, but generally the males greatly outnumber the females. A northern and a southern population can be distinguished, the differences being in growth rate and pigmentation. Each population supports a separate fishery, which operates on the ascending shoals. The history of the fisheries is outlined. The southern fishery has never been important because the fish available at the principal fishing locality are excessively pigmented. More suitable fish could be taken by operating further downstream, where the fish are typically at an earlier stage of maturity. The northern fishery has been vigorously prosecuted and overfishing was probably the cause of the decline in abundance of stock in 1947 and 1948. If there was overfishing, it operated purely by excessive removal of reproducers. The order of the optimum catch is empirically identified and a programme for the management of the stock, aiming at its rehabilitation, is recommended.

Sexual Selection in Dung Beetles .1. A Multivariate Study of the Morphological Variation in 2 Species of Onthophagus (Scarabaeidae, Onthophagini)

1987 ◽  
Vol 35 (2) ◽  
pp. 123 ◽  
Author(s):  
D Cook
Keyword(s):  
Sexual Selection ◽  
Sexual Dimorphism ◽  
Morphometric Analysis ◽  
Body Shape ◽  
Dung Beetles ◽  
Structural Polymorphism ◽  
Multivariate Study ◽  
History Of ◽  
Males And Females ◽  
Horned Beetles

Sexual dimorphism in horned beetles reflects a history of different selection pressures operating on males and females. A multivariate morphometric analysis was carried out on two scarabaeine dung beetles, Onthophagus binodis Thunberg and O. ferox Harold. There is clear structural polymorphism within O. binodis; horned males, females and hornless males were separated on the basis of body shape. Sexual dimorphism within O. ferox was established; sexes were separated according to the size of pronotal and cephalic horns. The effect of differential selection is discussed within the context of sexual selection.

Sexual dimorphism and life history of Keichousaurus hui (Reptilia: Sauropterygia)

2009 ◽  
Vol 29 (2) ◽  
pp. 401-408 ◽  
Author(s):  
Yen-Nien Cheng ◽  
Robert Holmes ◽  
Xiao-Chun Wu ◽  
Noel Alfonso
Keyword(s):  
Life History ◽  
Sexual Dimorphism ◽  
History Of

scholarly journals Life history of Tendaguru sauropods as inferred from long bone histology

Fossil Record ◽  
1999 ◽  
Vol 2 (1) ◽  
pp. 103-112 ◽  
Author(s):  
P. M. Sander
Keyword(s):  
Life History ◽  
Body Size ◽  
Sexual Dimorphism ◽  
Sexual Maturity ◽  
Upper Jurassic ◽  
Bone Histology ◽  
Long Bone ◽  
Large Mammals ◽  
Growth Series ◽  
History Of

Abstract. Sauropod dinosaurs present exceptional challenges in understanding their biology because of their exceptional body size. One of these, life history, can be inferred from the histology of their bones. For this purpose, the diverse sauropod assemblage of the Upper Jurassic Tendaguru beds was sampled with a new coring method which provided unprecented access to and insights into sauropod bone histology. Growth series of humeri and femora as well as long growth records from single bones suggest that all four sauropod taxa are characterized by continued growth after sexual maturity but that growth was determinate. Fibrolamellär bone is dominant in the samples, indicating that the bones of the Tendaguru sauropods grew at rates comparable to those of modern large mammals. The growth pattern of these sauropods thus combines typically reptilian traits with typically mammalian traits. In the details of their bone histology, the Tendaguru sauropod taxa show considerable variation which reflects life history. In addition, Barosaurus exhibits probable sexual dimorphism in bone histology. Das Verständnis der Biologie der sauropoden Dinosaurier wird durch ihre enorme Körpergröße außerordentlich erschwert. Allerdings kann ein Aspekt, die Lebensgeschichte, anhand der Histologie ihrer Knochen untersucht werden. Zu diesem Zweck wurde die diverse Sauropoden-Vergesellschaftung der oberjurassischen Tendaguru-Schichten beprobt, und zwar mit einer neuartigen Kernbohrmethode, die einen herausragenden Zugang und Einblick in die Knochenhistologie der Sauropoden ermöglichte. Wachstumsserien von Humeri und Femora sowie umfassende Überlieferungen des Wachstums von Individuen anhand einzelner Knochen machen es wahrscheinlich, daß alle vier Sauropoden-Taxa der Tendaguru-Schichten durch ein auch nach der Geschlechtsreife anhaltendes Wachstum gekennzeichnet waren. Allerdings ging das Wachstum nicht bis zum Tode des Tieres weiter, sondern kam bei einer etwas variablen Maximalgröße zum Stillstand. Fibrolamellärer Knochen ist der vorherrschende Knochentyp in den Proben, was anzeigt, daß die Tendaguru-Sauropoden mit für Säugetieren typische Raten wuchsen. Die Tendaguru-Sauropoden kombinerten also ein für Reptilien typisches Muster des Wachstums, nämlich nach der Geschlechtsreife anhaltendes Wachstum, mit für Säuger typischen Raten des Wachstums. Die verschiedenen Sauropoden-Taxa zeigen erstaunliche Unterschiede in den Details ihrer Knochenhistologie, die Unterschiede in der Lebensgeschichte belegen. Bei Barosaurus scheint außerdem ein Geschlechtsdimorphismus in der Histologie der Langknochen vorzukommen. doi:1002/mmng.1999.4860020107

scholarly journals Natural history of the rare and endangered snake Atractus ronnie (Serpentes: Colubridae) in northeastern Brazil

2019 ◽  
Vol 18 (1) ◽  
pp. 77-87
Author(s):  
Cristiana Ferreira-Silva ◽  
Samuel Cardozo Ribeiro ◽  
Edna Paulino de Alcantara ◽  
Robson Waldemar Ávila
Keyword(s):  
Sexual Dimorphism ◽  
Natural History ◽  
Diet Composition ◽  
Northeastern Brazil ◽  
Activity Period ◽  
Pitfall Traps ◽  
Insect Larvae ◽  
Rare And Endangered ◽  
History Of ◽  
Visual Searches

Natural history of the rare and endangered snake Atractus ronnie (Serpentes: Colubridae) in northeastern Brazil. The habitat use, activity period, sexual dimorphism, morphological variation, reproduction and diet composition of this fossorial and nocturnal snake are reported. The snakes were captured between 2008–2014 in the Chapada do Araripe in northeastern Brazil, and were collected by active visual searches, as well as in pitfall traps with drift fences. Although females are larger than males, the males have longer tails, and scale counts differ between the sexes. Reproduction is seasonal, occurring during the rainy season. Brood sizes rang from one to four eggs. Atractus ronnie preys on earthworms, in addition to ants (Crematogaster sp.) and insect larvae.

A remarkable new species of flesh-fly mimicking weevil (Coleoptera: Curculionidae: Conoderinae) from Southeastern Brazil

Zootaxa ◽  
2012 ◽  
Vol 3413 (1) ◽  
pp. 55 ◽  
Author(s):  
SERGIO A. VANIN ◽  
TADEU J. GUERRA
Keyword(s):  
New Species ◽  
Sexual Dimorphism ◽  
The Other ◽  
Southeastern Brazil ◽  
Serra Do Cipó ◽  
The Family ◽  
History Of ◽  
Species Type ◽  
And Behavior ◽  
Flesh Flies

Timorus sarcophagoides, new species (type-locality: Brazil, Minas Gerais, Santana do Riacho - Serra do Cipó, 43o35'W 19o17'S, 1200–1300m ASL), is described and illustrated. The new species can be distinguished mainly from the other species of the genus by the sexual dimorphism of the male rostrum armed with a hooked tubercle at the base of the dorsal carina, while the tubercle is absent in the female and the corresponding region of the carina is only tumid. The new species has a striking pattern of coloration and behavior that mimics flesh-flies in the family Sarcophagidae. Observations on the natural history of the new species are reported and discussed.

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