The life history of Chondrus crispus in culture

1972 ◽  
Vol 50 (5) ◽  
pp. 1055-1060 ◽  
Author(s):  
L. C-M. Chen ◽  
J. McLachlan
Keyword(s):  
Life History ◽  
Second Generation ◽  
Dorsal Surface ◽  
Similar Rate ◽  
Chondrus Crispus ◽  
Basal Disc ◽  
Male And Female ◽  
Rate Of Growth ◽  
History Of ◽  
Sexually Mature

The life history of the rhodophycean alga, Chondrus crispus, was completed in culture in about 20 months. Plants established from tetraspores formed male and female gametophytes and subsequently carposporophytes; carpospores in turn gave rise to plants with mature tetrasporangia. Tetraspores from these resulted in second generation gametophytes. Carpospores of plants from nature developed into tetrasporophytes; gametophytes derived from the tetraspores became sexually mature within a year. Sporophytic and gametophytic plants were, as expected, morphologically similar. Rate of growth of plants in cultures was comparable with published observations made on plants in nature. Preliminary experiments showed that, in culture, regeneration can occur from both the erect frond and the basal disc. In the latter, erect fronds may arise from any point on the dorsal surface of the disc.

The life history of Palmaria palmata in culture. A new type for the Rhodophyta

1980 ◽  
Vol 58 (11) ◽  
pp. 1250-1256 ◽  
Author(s):  
John P. van derMeer ◽  
Edna R. Todd
Keyword(s):  
Life History ◽  
Vegetative Growth ◽  
Palmaria Palmata ◽  
Recessive Mutation ◽  
Male And Female ◽  
Carpogonial Branch ◽  
History Of ◽  
New Type ◽  
Sexually Mature ◽  
Older Males

The life history of Palmaria palmata has been completed in culture. Tetraspores from diploid plants gave rise to male and female haploid plants which differed morphologically. Female plants were extremely small and became sexually mature only days after tetraspore release. Trichogynes were observed on plants only 4 days old, and remained conspicuous for several weeks. As the females aged, trichogynes declined in number and they could not be detected on plants 5 months old. In contrast, male plants required several (9–12) months of vegetative growth before they formed spermatia. As a consequence, females had to be fertilized by older males from preceding gametangial generations.The diploid tetrasporangial plants developed directly on fertilized females. As they enlarged, they completely overgrew the small females and formed their own holdfast attachments to the substrate. A recessive mutation resulting in green frond colour was used in crosses designed to yield red diploid tissue on green females after fertilization, thereby greatly facilitating observations on the development of the tetrasporangial phase.Preliminary observations indicate that the carpogonium is a single cell. There appears to be no carpogonial branch or auxilliary cell. The tetrasporangial phase develops from the zygote by simple mitotic divisions, suggesting that the life history is best interpreted as lacking a carposporophyte.

Influence of a reservoir with surface release on the life history of the mayfly Heterocloeon curiosum (McDunnough) (Ephemeroptera: Baetidae)

1981 ◽  
Vol 59 (2) ◽  
pp. 305-314 ◽  
Author(s):  
Boris C. Kondratieff ◽  
J. Reese Voshell Jr.
Keyword(s):  
Life History ◽  
Benthic Macroinvertebrates ◽  
Temperature Regime ◽  
Life Histories ◽  
Second Generation ◽  
Larval Instars ◽  
History Of ◽  
Lake Anna

The life history of Heterocloeon curiosum was compared in the impounded North Anna River (NAR) and the free-flowing South Anna River (SAR) in Virginia, U.S.A. The study site on the NAR was 32 km below Lake Anna, a surface-release reservoir. Heterocloeon curiosum was bivoltine in both rivers with two summer generations and probable overwintering in the egg stage. It passed through 10 larval instars (range 9–12) in both rivers. The density of larvae was twice as great in the SAR as the NAR. Factors which may have contributed to the lesser success of H. curiosum in the NAR included bottom scouring produced by sudden increases in discharge, absence of the macrophyte Podostemum, quality of available food, and alterations of the temperature regime. Of these four factors, temperature probably had the most significant effect. The emergence of the second generation was 1 month later in the NAR because the reservoir delayed the normal seasonal cooling of the river. The nonoptimal temperature regime appeared to significantly reduce the fecundity of H. curiosum in the NAR. Our data indicate that surface-release reservoirs may have subtle but significant effects on the life histories of benthic macroinvertebrates.

LIFE HISTORY STUDIES OF THE TOBACCO FLEA BEETLE, EPITRIX HIRTIPENNIS (MELSHEIMER) (COLEOPTERA: CHRYSOMELIDAE)

1987 ◽  
Vol 22 (3) ◽  
pp. 237-244 ◽  
Author(s):  
W. Davis Martin ◽  
G. A. Herzog
Keyword(s):  
Life History ◽  
Larval Stage ◽  
Flea Beetle ◽  
Pupal Stage ◽  
Adult Emergence ◽  
Adult Longevity ◽  
Male And Female ◽  
Controlled Conditions ◽  
History Of ◽  
The Mean

The life history of the tobacco flea beetle, Epitrix hirtipennis (Melsheimer) (= Epitrix parvula Fab.) was studied under the controlled conditions of 27 ± 2.8°C, 80 ± 6% and a 14L:10D photophase. Eggs matured in ca. 4 days, the larval stage, including 3 instars, developed in 13 days, prepupal development took 3 days and the pupal stage lasted approximately 5 days. There was a 24 day interval between oviposition and adult emergence. Females laid 3.1 eggs/day with a 13 day period between adult emergence and first oviposition. The mean number of total eggs/female was 138.6 ± 14.7. Female oviposition continued until a few days before death and adult longevity was approximately 70 days. A visual means of distinguishing between male and female beetles was also developed.

The Development and Life History of Echinorhynchus truttae Schrank, 1788 (Acanthocephala)

1966 ◽  
Vol 40 (1-2) ◽  
pp. 11-32 ◽  
Author(s):  
J. B. E. Awachie
Keyword(s):  
Life History ◽  
Embryonic Development ◽  
Intermediate Host ◽  
Definitive Host ◽  
Room Temperature ◽  
Final Host ◽  
Gammarus Pulex ◽  
Pyloric Region ◽  
History Of ◽  
Sexually Mature

The details of the post-embryonic development of Echinorhynchus truttae in the intermediate host, Gammarus pulex, and the final host, Salmo truttae, are described.The cystacanths of this species are sexually mature and are formed about 82 days after infection at room temperature, ca. 17°C.Copulation takes place in the definitive host soon after the worms enter the pyloric region of the intestine. About 10 weeks after infection, mature eggs are passed out with the faeces of fish.

The Life History of the Cirratulid Worm, Cirriformia Tentaculata, on an Intertidal Mudflat

1964 ◽  
Vol 44 (1) ◽  
pp. 47-65 ◽  
Author(s):  
J. D. George
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Seasonal Variation ◽  
Annual Cycle ◽  
Seasonal Fluctuation ◽  
Mortality Data ◽  
Intertidal Mudflat ◽  
History Of ◽  
Causes Of Mortality ◽  
Sexually Mature

The seasonal fluctuation in numbers of C. tentaculata was investigated from December 1959 until February 1962. The lowest numbers were recorded in April followed by a rapid increase in numbers during May. The magnitude of the increase varied from year to year, as also did the number of peaks that occurred during the summer months.The worm was shown to have an extended breeding season from the end of March to September during which several spawning ‘bursts’ took place. Experiments suggest that some spawning may occur when the mudflat is inundated by the rising tide, although spawning was not observed in the field.The population of C. tentaculata exhibited an annual cycle of growth which was influenced by the seasonal variation in temperature. Laboratory observations suggest that a temperature of about 20° C is optimal for the growth of young worms. The growth rate (8 mm/year) is slow compared with that of other polychaetes.It is tentatively concluded from the field mortality data that between 10 and 16 % of animals survive to an age at which they are sexually mature; between 6 and 8 % of each generation reach an age of 15 months. Causes of mortality in the population are briefly discussed.

The ecology of Lagos Lagoon. III. The life-history of Branchiostoma nigeriense Webb

1958 ◽  
Vol 241 (683) ◽  
pp. 335-353 ◽  
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Annual Cycle ◽  
Brackish Water ◽  
Threshold Value ◽  
Embryonic Period ◽  
Rate Of Growth ◽  
Lagos Lagoon ◽  
History Of

A study has been made of the distribution of the lancelet Branchiostoma nigeriense in the neighbourhood of Lagos. From observations on the development of fertilized ova in the laboratory, an estimate of the duration of the embryonic period in this species has been made. Systematic collections of both larvae and adults were made during the years 1953 to 1955, and from these the duration of the life cycle and the rate of growth of both the larva and the adult have been assessed. It has been established that lancelets in the brackish lagoons at Lagos are derived annually from marine populations outside the harbour. The larvae enter brackish water when the salinity is not lower than 13 parts per thousand in the autumn, metamorphose at the end of December and give rise to adults which colonize the sand deposits of the lagoons. The adults reach maturity and spawn in the spring, but die shortly afterward when the salinity of the water falls below the threshold value for survival. The marine populations have an annual cycle, spawning from August to October or November each year.

Life History of the Endemic Saddleback Crayfish, Faxonius medius (Faxon, 1884), (Decapoda: Cambaridae) in Missouri, USA

2019 ◽  
Vol 24 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Robert DiStefano ◽  
Jacob Westhoff ◽  
Christopher Rice ◽  
Amanda Rosenberger
Keyword(s):  
Life History ◽  
Sympatric Species ◽  
First Year ◽  
Geographic Context ◽  
Ratio Size ◽  
Small Streams ◽  
History Of ◽  
Egg Brooding ◽  
First Year Of Life ◽  
Sexually Mature

Abstract The saddleback crayfish, Faxonius medius (Faxon, 1884), is endemic to a single drainage in eastern Missouri, USA, that is affected by heavy metals mining, and adjacent to a rapidly-expanding urban area. We studied populations of F. medius in two small streams for 18 months to describe the annual reproductive cycle and gather information about fecundity, sex ratio, size at maturity, and size-class structure. We also obtained information about the species’ density at supplemental sites. The species, though rare in a geographic context, is locally abundant; we captured a monthly average of more than 75 F. medius from each of the two study populations. Densities of F. medius were high relative to several sympatric species of Faxonius Cope, 1872 and Cambarus Erichson, 1846. The species exhibited traits of an r-strategist life history; it was relatively short-lived and early to maturity. Its fecundity and egg size were comparable to Ozark congeners. Breeding season occurred in autumn, perhaps extending into early winter. Egg brooding occurred primarily in April. Young-of-year first appeared in samples in June. We estimated that these populations contained 2 to 3 size-classes, and most individuals became sexually mature in their first year of life. Life history information presented herein will be important for future conservation efforts.

Life history of Amblyseius fustis (Pritchard and Baker), an indigenous predator of the cassava red mite, Oligonychus gossypii (zacher) in south western Nigeria

1985 ◽  
Vol 6 (2) ◽  
pp. 193-197 ◽  
Author(s):  
T. O. Ezulike ◽  
J. A. Odebiyi
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Relative Humidity ◽  
Developmental Stages ◽  
Developmental Period ◽  
Life Stages ◽  
Male And Female ◽  
Significant Difference ◽  
History Of ◽  
Male To Female

AbstractThe life history of Amblyseius fustis (Pritchard and Baker) was studied in the laboratory at a fluctuating temperature and relative humidity ranging from 24.4 to 28.0°C and 55.5 to 75.6%, respectively. The developmental stages consist of egg, larva, protonymph, deutonymph and adult. The life cycle, from egg to adult of both male and female was about 8 days, while longevity was about 19.2 days. Mated female laid an average of 18.8 eggs. There was no significant difference in the longevity and fecundity of predators fed on different life stages of the host. The proportion of male to female in the progeny of mated females was 1:4.A. fustis has a shorter developmental period and lives longer than its prey, but the latter is more fecund (26.9 eggs/♀) and has a higher proportion of females in its progeny (1:4.8). The shorter developmental period and the longer life span of the predator are likely to offset the higher fecundity of the prey.

scholarly journals CHROMOSOMAL ALTERNATION OF GENERATIONS IN NEREOCYSTIS LUETKEANA (MERTENS) POSTELS AND RUPRECHT

1961 ◽  
Vol 39 (7) ◽  
pp. 1711-1724 ◽  
Author(s):  
Lindley Kemp ◽  
Kathleen Cole
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Nuclear Division ◽  
Basal Cells ◽  
Cytological Examination ◽  
Male And Female ◽  
Nereocystis Luetkeana ◽  
History Of ◽  
Alternation Of Generations

A cytological examination of the life history of Nereocystis luetkeana has shown that an alternating chromosome number corresponds to the morphological alternation of generations. The first division sequence of the zoosporangial nucleus is meiotic and is followed by three, usually synchronous, mitotic divisions. Thirty-two zoospores are liberated from each sporangium, and their germination gives rise to male and female gametophytes. Genotypic determination of the sexes is believed to take place in Nereocystis. Mitosis in the gametophytes is regular and cytokinesis follows each nuclear division, producing few cells in the female and many cells in the male gametophytes. Thirty-one chromosomes can be counted at the mitotic prophase. Oogamy exists in Nereocystis and fertilization takes place after the egg is extruded from the oogonium. Nuclear division in the sporophyte appears to be preceded by division of the nucleolus. Colorless and non-septate rhizoids develop as elongations of the basal cells of the sporophyte.Temperature is an important factor in the development of various stages of the life cycle of Nereocystis grown in culture, particularly in the gametophytic stage where sexual structures are produced only at temperatures less than 10 °C and vegetative growth is most prolific at 14–18 °C.Some of the unfertilized eggs develop parthenogenetically and give rise to stunted, deformed plants with multinucleate cells.

OBSERVATIONS ON THE LIFE HISTORY OF APAMEA VELATA WLK

1944 ◽  
Vol 76 (11) ◽  
pp. 223-225 ◽  
Author(s):  
V. G. Dethier
Keyword(s):  
Life History ◽  
Second Generation ◽  
Widespread Species ◽  
History Of

To the best of the writer's knowledge, complete descriptions of the larva of this widespread species do not occur in the literature. The larva, one of the most frequently encountered grass-feeders, may be collected abundantly by sweeping lush grasslands. It is first noticed in numbers early in May. All individuals are small, having hatched from eggs laid by moths which had overwintered as pupae. By the end of May the majority have pupated, and adults appear on the wing in June. From the eggs of these developes a second generation. A third appears in August.

Sign in / Sign up

Export Citation Format

Share Document