Life history of the frog Crinia signifera in Tasmania, Australia

2005 ◽  
Vol 53 (1) ◽  
pp. 21 ◽  
Author(s):  
B. Lauck
Keyword(s):  
Life History ◽  
Body Size ◽  
Sexual Maturity ◽  
Reproductive Traits ◽  
Pitfall Trap ◽  
Male Reproductive Success ◽  
Female Life History ◽  
Primary Determinant ◽  
History Of ◽  
One Year

A pitfall-trap study was used to investigate the importance of body size, age, body condition (males only), season and growth history as determinates of male and female life-history fitness traits in a population of the frog Crinia signifera. Specimens were dissected to determine physiological characteristics and skeletochronology was used to determine age. Females lived longer and attained a larger size than males by delaying sexual maturity. Most females and males attained sexual maturity after three and two years, respectively; although eggs were found in females as young as one year old. Body size (but not age) was the primary determinant of fecundity, total reproductive output (clutch mass) and oviduct mass for females. Season was the predominant influence on egg size, with smaller eggs produced in summer than in other seasons. Direct investment in male gonads (testes size) was determined by body size and also by age. This, and the fact that sexual size dimorphism in amphibians is commonly female biased, suggests that male size is not necessarily the primary determinant of male reproductive success in C. signifera. Whereas selection on reproductive traits in females is likely to act predominantly on body size, selection in males is also likely to act on survival.

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

Age, growth, and reproduction in Hector's dolphins

1991 ◽  
Vol 69 (6) ◽  
pp. 1689-1700 ◽  
Author(s):  
Elisabeth Slooten
Keyword(s):  
Life History ◽  
Body Size ◽  
Sexual Maturity ◽  
Fishing Gear ◽  
Male And Female ◽  
Pulp Cavity ◽  
Traditional Procedure ◽  
History Of ◽  
Growth And Reproduction ◽  
Beach Cast

Data are provided on the reproductive biology and life history of Hector's dolphin, Cephalorhynchus hectori, a species found only in New Zealand waters. Samples were taken from 60 dolphins found beach-cast or killed incidentally in fishing gear. Male and female reproductive tracts were examined macroscopically and histologically, and tooth sections provided an age estimate for each individual. The traditional procedure for preparing dolphin teeth was simplified by using a faster stain and more readily available embedding and sectioning equipment. An important advantage of this method is that it facilitates the cutting of thinner sections, increasing the chances of obtaining a section through the centre of the pulp cavity. Sectioning revealed an open pulp cavity in all the teeth examined. The maximum observed age was 19 years for females and 20 years for males. Females reach a larger body size than males, and are apparently larger than males at any given age. Males appear to reach sexual maturity between 6 and 9 years of age, whereas females give birth to their first calf at 7–9 years of age. Mature males have extremely large testes relative to their body size. The largest male found in this study weighed 41.5 kg, with testes (including epididymides) totalling 1.21 kg.

On the Correlation of the Life-history of the Acephaline Gregarine, Gonospora, with the Sexual Cycle of its Host

Parasitology ◽  
1930 ◽  
Vol 22 (4) ◽  
pp. 505-509 ◽  
Author(s):  
C. C. Hentschel
Keyword(s):  
Life History ◽  
Sexual Maturity ◽  
Sexual Cycle ◽  
History Of

1. In general there is a correlation between the life-history of Gonospora arenicolae and the sexual cycle of its host, Arenicola ecaudata, similar to that between G. varia and Audouinia tentaculata.2. In the species under consideration the correlation is not so definite and the life-history of a generation of parasites does not necessarily coincide with a sexual cycle of the host. This is complicated by the double annual spawning of the host.3. The formation of sporocysts is simultaneous with the sexual maturity of the worm.4. It is suggested that, as in Audouinia, a secretion produced by the gonads stimulates the development of the gregarine.5. The ejection of the sporocysts with the gametes was observed.6. It is suggested that phagocytosis may be the cause of the rupture of the gametocysts in this species.

Life history of Mysis stenolepis Smith (Crustacea, Mysidacea)

1975 ◽  
Vol 53 (7) ◽  
pp. 942-952 ◽  
Author(s):  
T. Amaratunga ◽  
S. Corey
Keyword(s):  
Young Adults ◽  
Life History ◽  
New Brunswick ◽  
Shallow Water ◽  
Field Study ◽  
Sexual Maturity ◽  
Developmental Stages ◽  
Shallow Waters ◽  
Passamaquoddy Bay ◽  
History Of

A 17-month field study showed that Mysis stenolepis in Passamaquoddy Bay, New Brunswick lives for about 1 year. Young are released in shallow water early in spring and grow rapidly during the summer. In the fall, young adults migrate to deeper water where they reach sexual maturity. Transfer of sperm lakes place during winter in deeper regions of the Bay. soon after which the males die. Females survive and in spring migrate to shallow waters to release young after which they die. Females breed once and carry an average of 157 young per brood. Developmental stages of the postmarsupial young are described and discussed.

THE ECOLOGY AND LIFE HISTORY OF RETUSA OBTUSA (MONTAGU) (GASTROPODA, OPISTHOBRANCHIA)

1967 ◽  
Vol 45 (4) ◽  
pp. 397-405 ◽  
Author(s):  
S. Tyrell Smith
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Life Span ◽  
High Tide ◽  
Breeding Period ◽  
Protandrous Hermaphrodite ◽  
History Of ◽  
Natural Breeding ◽  
One Year ◽  
Short Time

The habitat, diet, life history, and reproductive cycle of Retusa obtusa were investigated over a period of [Formula: see text] years in a population found in the Inner Harbour at Barry, Glamorgan, U.K. A technique was devised for extracting Retusa from the mud of this area. R. obtusa occurs in the topmost 3.5 cm of fine mud covering Barry harbor, which is immersed by the sea for only a short time at each high tide. The principal prey was found to be Hydrobia ulvae.The life cycle was found to be annual, the adults dying in spring, following the natural breeding season. Occasionally, a short extra breeding period occurs in the fall. The life span in no case greatly exceeded one year. Retusa is a protandrous hermaphrodite, and copulates in the fall. The eggs mature through the late fall and the winter, a few at a time, until oviposition occurs in the spring. The average number of eggs produced per individual was 33, deposited in 1–4 egg batches. Development is direct.

Comparative life history features of the western spotted frog, Rana pretiosa, from low- and high-elevation populations

1975 ◽  
Vol 53 (9) ◽  
pp. 1254-1257 ◽  
Author(s):  
Lawrence E. Licht
Keyword(s):  
British Columbia ◽  
Life History ◽  
Body Size ◽  
Sexual Maturity ◽  
High Elevation ◽  
The Body ◽  
Female Fecundity ◽  
Size At Sexual Maturity ◽  
Rana Pretiosa

Comparisons are made of life history features of the western spotted frog, Rana pretiosa pretiosa, living at 70 m in southwestern British Columbia, and 2600 m in Yellowstone Park, Wyoming.Lowland tadpoles remain longer as larvae and transform at twice the body size as highland tadpoles.Growth rates of juveniles and adults are rapid in the lowland population and the same amount of growth achieved by them in 2–3 years takes 8–10 years for highland frogs.Body size at sexual maturity is the same for frogs from both populations, but B.C. frogs breed at half the age of Wyoming frogs. Female fecundity, the number of eggs at spawning, is the same, but lowland females breed annually, while high-elevation females breed only every 2 or 3 years.Various explanations are put forth to account for observed differences.

The life history of a tropical dragonfly: Cora marina (Odonata: Polythoridae) in Guanacaste, Costa Rica

1996 ◽  
Vol 12 (4) ◽  
pp. 573-581 ◽  
Author(s):  
Gordon Pritchard
Keyword(s):  
Life History ◽  
Costa Rica ◽  
Hyporheic Zone ◽  
Flight Period ◽  
Low Oxygen ◽  
Wet Season ◽  
Oxygen Conditions ◽  
History Of ◽  
One Year ◽  
Oviposition Sites

ABSTRACTThe life history of Cora marina was followed for one year in two permanent streams at 600 m elevation in Guanacaste National Park; Costa Rica. The water temperature was c. 21°C year-round, but there was a distinct wet-dry seasonality, very little rain falling from January to May. In both streams, C. marina was univoltine. Adults first appeared at the beginning of May and the flight period coincided with the wet season. The availability of water-soaked logs as oviposition sites probably restricts reproduction to the wet season. Eggs hatched from mid-July to December. Recruitment to subsequent larval instars was slow during the wet season but increased at the start of the dry season. Final-instar larvae were collected from March to October. Oviposition in logs above the stream and the ability to live in the low oxygen conditions of the hyporheic zone probably allow eggs and small larvae to survive wet season spates.El ciclo biológico de una libelula tropical: Cora marina (Odonata: Polythoridae) en Guanacaste, Costa Rica.

STUDIES ON CESTODES OF THE GENUS TRIAENOPHORUS FROM FISH OF LESSER SLAVE LAKE, ALBERTA: V. DESCRIPTION AND LIFE HISTORY OF TRIAENOPHORUS STIZOSTEDIONIS N.SP.

1945 ◽  
Vol 23d (5) ◽  
pp. 117-127 ◽  
Author(s):  
Richard B. Miller
Keyword(s):  
Life History ◽  
Male Genitalia ◽  
Sexual Maturity ◽  
Morphological Characters ◽  
Parietal Peritoneum ◽  
Stizostedion Vitreum ◽  
Pike Perch ◽  
History Of

Triaenophorus stizostedionis is a pseudophyllidean cestode that occurs as an adult in the intestine of the pike-perch, Stizostedion vitreum. It differs from T. crassus and T. nodulosus in several morphological characters but particularly in the shape of the scolex hooks and the size and disposition of the male genitalia. Sexual maturity is attained in the spring; spawning and death take place during the first two weeks of June. The eggs average 56 μ long by 40 μ wide. The coracidia average 73 by 71 μ. The procercoid develops in the copepod, Cyclops bicuspidatus, in from 10 days to two weeks. When fully grown it reaches 220 μ. The plerocercoids occur encysted on the visceral and parietal peritoneum of the trout-perch, Percopsis omiscomaycus. The life history is completed when an infested trout-perch is swallowed by a pike-perch.

A multi-year and multi-site population study on the life history of Salamandrina perspicillata (Savi, 1821) (Amphibia, Urodela)

2008 ◽  
Vol 29 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Carlo Utzeri ◽  
Claudio Angelini ◽  
Damiano Antonelli
Keyword(s):  
Life History ◽  
Body Size ◽  
Population Study ◽  
Climatic Conditions ◽  
Life History Variation ◽  
Differential Growth ◽  
History Of ◽  
Natural Pond ◽  
The Mean ◽  
Site Population

Abstract We studied nine populations of Salamandrina perspicillata for two to nine years and described the life history variation among these population. Despite experiencing similar climatic conditions, populations differed in mean body size: populations using still water bodies for oviposition were larger body-sized than those using brooks. One semi-natural pond was used by particularly small individuals and was probably recently colonised. The mean body size of ovipositing females varied from year to year. Measurements of individuals in successive years showed that the tail grew more than the trunk and this differential growth increased with age. Females did not oviposit every year and, within a given population, the number of ovipositing females varied widely from year to year.

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