scholarly journals Life history of the Muricid Gastropod, Cronia margariticola(Broderip, 1833): Growth Mode Transition with Season and Sexual Maturity

2004 ◽  
Vol 59 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Ishida So
Keyword(s):  
Life History ◽  
Sexual Maturity ◽  
Growth Mode ◽  
Mode Transition ◽  
History Of

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.

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.

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

Aspects of the life history of Meganyctiphanes norvegica (M. Sars), Crustacea (Euphausiacea), in Passamaquoddy Bay

1974 ◽  
Vol 52 (4) ◽  
pp. 495-505 ◽  
Author(s):  
K. W. Hollingshead ◽  
S. Corey
Keyword(s):  
Life History ◽  
Life Span ◽  
Sexual Maturity ◽  
Gonadal Development ◽  
Age Group ◽  
Group I ◽  
Passamaquoddy Bay ◽  
History Of ◽  
Meganyctiphanes Norvegica ◽  
First Time

Monthly collections of Meganyctiphanes norvegica for a 19-monih period in Passamaquoddy Bay showed that these euphausiids were present in the bay in varying numbers from February to November but virtually disappeared in December and January. Sexual maturity is attained in 1 year with gonadal development taking 3 months, and spawning occurring in July and August. The resulting generation will breed and spawn for the first time the next July as age group I. Age group I grows from April until August; from September until March, very little growth occurs. After a second breeding and spawning, the animals die, having a life span of 2 years.

The life history of Halosaccion ramentaceum

1981 ◽  
Vol 59 (4) ◽  
pp. 433-436 ◽  
Author(s):  
John P. van der Meer
Keyword(s):  
Life History ◽  
Chromosome Number ◽  
Sexual Maturity ◽  
Mutant Phenotype ◽  
Sexual Cycle ◽  
Palmaria Palmata ◽  
Male And Female ◽  
Haploid Male ◽  
History Of ◽  
Mendelian Transmission

The complete life history of Halosaccion ramentaceum has been determined. It is very similar to that of Palmaria palmata, consisting of haploid male and female gametophytes alternating with a diploid tetrasporophyte. As for P. palmata, there is no carposporophyte. Male and female gametophytes attain sexual maturity almost a generation apart. Whereas male plants require approximately 1 year's growth before producing spermatia, female gametophytes are microscopic and reach sexual maturity only a few days after tetraspore germination. The diploid tetrasporophyte initiates its development on the female, but almost immediately forms an independent holdfast on the substratum beside the female. The first diploid fronds arise from that holdfast after it is well established.The existence of a complete sexual cycle was proven by demonstrating: fertilization of trichogynes by spermatia; meiosis in tetrasporangia, with a chromosome number of n = ~24 in gametophytes and 2n = ~48 in tetrasporophytes; and by documenting the Mendelian transmission of a mutant phenotype from the male parent to the F1 gametophytes.

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.

The Life-History of Limnaea truncatula under Laboratory Conditions

1953 ◽  
Vol 27 (1-2) ◽  
pp. 17-28 ◽  
Author(s):  
S. B. Kendall
Keyword(s):  
Life History ◽  
Incubation Period ◽  
Environmental Conditions ◽  
Sexual Maturity ◽  
Atmospheric Temperature ◽  
Egg Laying ◽  
Rate Of Growth ◽  
Laboratory Conditions ◽  
Controlled Conditions ◽  
History Of

1. This paper describes the life-history of Limnaea truncatula under laboratory conditions.2. Under controlled conditions sexual maturity may be reached in 28 days and egg laying continues for the greater part of the snail's life.3. Under good environmental conditions each snail may lay as many as 60 eggs in a single day and a total of more than 3,000 in a life approximately a year.4. Egg laying occurs during every month and at temperatures as low as 10°C. to 11°C. The incubation period of the egg is related to the atmospheric temperature.5. The longevity of the snail is likely to be related to its rate of growth and to environmental conditions including periods of drought.6. The snail remains fully active at temperatures as low at 1.5°C.Sustained temperatures much above 20°C. are unfavourable, temperaturesabove 25°C. proving markedly deleterious.

scholarly journals Sexual Maturity and Early Life History of the Mudskipper Scartelaos gigas (Pisces, Gobiidae): Implications for Conservation

2011 ◽  
Vol 14 (4) ◽  
pp. 403-410 ◽  
Author(s):  
Jin-Koo Kim ◽  
Hea-Ja Baek ◽  
Jae-Won Kim ◽  
Dae-Soo Chang ◽  
Joo-Il Kim
Keyword(s):  
Life History ◽  
Early Life ◽  
Sexual Maturity ◽  
Early Life History ◽  
History Of

Local Differences in the Life History of the Lobster (Homarus americanus) on the Coast of the Maritime Provinces of Canada

1936 ◽  
Vol 2 (1) ◽  
pp. 41-88 ◽  
Author(s):  
W. Templeman
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Nova Scotia ◽  
Sexual Maturity ◽  
Homarus Americanus ◽  
Summer Temperature ◽  
Maritime Provinces ◽  
Commercial Catch ◽  
History Of ◽  
Sexually Mature

The hatching and moulting of the lobster are earlier in waters with a high than in those with a lower summer temperature. Moulting is about one week later for each degree lower summer temperature. In such high temperature areas as Malpeque bay two moultings occur during the year in most lobsters between 14 and 22 cm. in length. In the whole southern gulf of St. Lawrence area female lobsters as small as 18 to 21 cm. in length may carry eggs, while in the Grand Manan area with a summer temperature 5 to 8 °C. lower, the smallest sexually mature females are about 34 cm. in length. The growth per moult of the female lobster falls considerably below that of the male when sexual maturity approaches, thus in the southern gulf of St. Lawrence the female growth rate slows down rapidly after 18 to 21 cm. and in southern Nova Scotia at about 30 cm. In the southern gulf area at small sizes more males than females appear in the commercial catch, at larger sizes more females and at very large sizes nearly all the lobsters caught are males. Average sizes of lobsters in the commercial catch are considerably smaller in the southern gulf area than in southern Nova Scotia and at Grand Manan.

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