The reproductive cycles and geographical distribution of some common eastern Australian prosobranchs (Mollusca: Gastropoda)

1974 ◽  
Vol 25 (1) ◽  
pp. 63 ◽  
Author(s):  
AJ Underwood
Keyword(s):  
Reproductive Cycle ◽  
Common Species ◽  
Food Sources ◽  
Southern Limit ◽  
Air Temperatures ◽  
Eastern Australia ◽  
Planktotrophic Larvae ◽  
The Times ◽  
Reproductive Cycles ◽  
Spawning Periods

The taxonomic positions and Australian distributions of 10 common species of intertidal prosobranchs from eastern Australia were established from museum collections and published records. Patellanax peroni (Blainville), Subninella undulata (Solander) and Littorina unifasciata Gray have a southern distribution (from latitude 43� 30'S.) reaching as far north as 26� S., but not to the tropic of Capricorn. Austrocochlea constricta (Lamarck), Nerita atramentosa Reeve and Bembicium nanum (Lamarck) have the same southern limit as the former species but extend northwards to the tropic of Capricorn. Montfortula rugosa (Quoy & Gaimard) and Cellana tramoserica (Sowerby) extend further north to northern Queensland (17�S.). Nodilittorina pyramidalis (Quoy & Gaimard) and Morula marginalba Blainville have a northern distribution, occurring throughout the Pacific, and extend southwards to southern New South Wales (37� 30'S.). These four types of distribution are briefly discussed in relation to the Australian faunistic provinces. Monthly samples from March 1972 to May 1973 of the ovaries of the 10 species were fixed for examination by light microscopy. The numbers of immature and mature oocytes were recorded to establish the times and seasonal duration of gametogenesis, vitellogenesis and spawning. The time of spawning for most species was confirmed from the presence on the shore of egg capsules or newly settled juveniles. The external appearance of male and female gonads proved unreliable for estimation of the phases of reproductive cycle. The 10 species showed a wide variety of pattern and timing of reproductive cycle at one locality, which did not correlate with their overall geographical distributions, zonation pattern on the shore or phylogenetic relationships. The possible importance of seawater and air temperatures as stimuli for initiation and cessation of phases of the reproductive cycles is discussed. Some species are influenced by temperature changes. The spawning periods of N. pyramidalis, L. unifasciata, M. marginalba and B. nanum fell within the period of maximum availability of phytoplankton (August to March). All these species have long-term planktotrophic larvae. With the possible exception of Nerita atramentosa, which breeds during the same period as the previous species, all the other species are archaeogastropods with short-term lecithotrophic larvae, which are independent of the availability of phytoplankton food sources. Austrocochlea constricta breeds throughout the year, Patellanax peroni either from June to September or from February to May. Cellana tramoserica breeds from March to October and Subninella undulata and Montfortula rugosa from October/November to May. All of the archaeogastropods, especially Patellanax peroni, retain unshed mature oocytes from one year to the next. Nodilittorina pyramidalis, Littorina unifasciata, Bembicium nanum, Nerita atramentosa and Morula marginalba all show cytolysis and resorption of unshed oocytes.

Ecology of Frillneck Lizards, Chlamydosaurus-Kingii (Agamidae), in Tropical Australia

1989 ◽  
Vol 16 (5) ◽  
pp. 491 ◽  
Author(s):  
R Shine ◽  
R Lambeck
Keyword(s):  
Activity Patterns ◽  
Common Species ◽  
Body Temperatures ◽  
Wet Season ◽  
Ambient Temperatures ◽  
Air Temperatures ◽  
Highly Correlated ◽  
Vantage Points ◽  
Reproductive Cycles ◽  
Free Ranging

Radiotelemetric monitoring of 18 free-ranging frillneck lizards in Kakadu National Park, combined with dissection of museum specimens, provided extensive data on the natural history and general ecology of this large and spectacular lizard. Activity patterns and reproductive cycles are highly seasonal, with lizards inactive during the drier (and cooler) months of the year. Frillnecks are primarily arboreal and are relatively unselective with regard to the species of tree used except that one common species, Eucalyptus confertyora, is avoided. Telemetered lizards usually clung to branches high in the canopy. During the mating season (November-December), males had larger activity ranges than did females (means of 2.5 vs 0.7 ha) and made longer daily movements (means of 69 vs 23 m). Frillneck lizards bask briefly in the morning, but body temperatures follow ambient temperatures for most of the day. Thermal heterogeneity in the lizards' habitat is low, so opportunities for behavioural regulation (especially reduction) of body temperature are limited. Body temperatures are highly correlated with air temperatures and are often close to 40�C. Female frillnecks are considerably smaller than males, and they produce 4-13 eggs during the wet season. Chlamydosaurus are apparently unique among reptiles in using bipedal locomotion during routine foraging. These lizards are 'sit and wait' predators, descending from arboreal vantage points to seize lepidopteran larvae or massed swarms of hymenopteran or isopteran alates. Many different types of insects are eaten, but vertebrate prey items are rarely taken.

Environmental and Genetic Control of Reproduction in Danthonia caespitosa Populations

1978 ◽  
Vol 26 (3) ◽  
pp. 351 ◽  
Author(s):  
KC Hodgkinson ◽  
JA Quinn
Keyword(s):  
Floral Induction ◽  
Flag Leaf ◽  
Day Length ◽  
Herbarium Specimens ◽  
Floral Initiation ◽  
Inflorescence Development ◽  
Southern Limit ◽  
The North ◽  
Eastern Australia ◽  
Controlled Environments

Seedlings and older plants of five populations of Danthonia caespitosa from south-eastern Australia were grown in controlled environments and in a transplant garden to determine the effect of day length, temperature, and vernalization of floral initiation and inflorescence development. The populations were selected from widely separated sites which spanned the latitudinal range (31-42°S.) for the species and extended from a hot, semiarid environment in the north to a relatively cool and moist temperature environment in the south. Examination of herbarium specimens indicated that seed set could occur as early as mid September at the northern limit for the species and not before mid January at the southern limit (Tasmania). In a uniform transplant garden located at Deniliquin (latitude 35° 23′S.) plants from the northern site reached anthesis 4 weeks earlier than plants from southern sites. Controlled environment experiments revealed that D. caespitosa is a long-day plant. Northern populations required a 9 . 5 hr day length or longer for floral induction compared with 11 hr or longer for southern populations. The number of days in inductive conditions (outside, day length 13.5 hr) required for floral initiation was 5-7 for the three most northern populations and 21-25 days for the two southern populations. Inflorescence development (initiation to flag leaf stage) was considerably slower in southern populations. All but the most northern population responded to vernalization. Flowering was earlier in temperatures that were optimal for plant growth. At high temperatures (36/31°C day/night) flowering was not significantly delayed for the three most northern populations, but was for the two southern populations, and florets contained caryopses in only the three northern populations. These results suggest that in cool and moist temperate habitats reproduction of this species is programmed by day length and temperature effects on floral initiation and development to coincide with a predictable growing season, whereas in hot semiarid habitats this control is relaxed, which permits opportunistic reproduction whenever soil moisture and temperature permit growth.

A comparative account of the reproductive cycles of five species of marine mussels (Bivalvia: Mytilidae) in the vicinity of Fremantle, Western Australia

1967 ◽  
Vol 18 (2) ◽  
pp. 175 ◽  
Author(s):  
BR Wilson ◽  
EP Hodgkin
Keyword(s):  
Reproductive Cycle ◽  
Western Australia ◽  
Marine Species ◽  
Spawning Season ◽  
Latitudinal Distribution ◽  
Marine Mussels ◽  
Reproductive Cycles ◽  
Determining Factor ◽  
Pacific Species

Descriptions are given of the reproductive cycles of five marine species of mussels. Two of these species have a southern Australian distribution and three are tropical Indo-Pacific species or have Indo-Pacific affinities. The reproductive cycles differ significantly, each species exhibiting a characteristic breeding pattern. A distinction is drawn between the season of gametogenic activity and the much narrower season of actual spawning. In four of the species the major features of the reproductive cycle correlate with latitudinal distribution. This is interpreted as evidence supporting the role of temperature as a principal determining factor in the control of broader aspects of the reproductive cycle (i.e. duration and season of gametogenic activity). Differences in finer details of the reproductive cycles (e.g. spawning season and number of spawning peaks) appear to be controlled by unknown factors besides temperature.

The distribution of the greater broad-nose bat Scoteanax rueppellii (Microchiroptera: Vespertilionidae) in relation to climate and topography.

2006 ◽  
Vol 28 (1) ◽  
pp. 77
Author(s):  
P. D. Wilson
Keyword(s):  
New South ◽  
Species Distributions ◽  
Museum Collections ◽  
Southern Limit ◽  
Climate Matching ◽  
Matching Algorithm ◽  
South Wales ◽  
Eastern Australia ◽  
Wide Range ◽  
Occurrence Records

Concepts of the distribution of the greater broad-nose bat (Scoteanax rueppellii) have changed significantly as occurrence records have accumulated over the years. Early accounts of the species' distribution suggested that it was restricted to the heavily timbered areas of eastern Australia, and occurred over a wide range of altitudes. However, recent summaries of the distribution of the species differ significantly from these early accounts. To reconcile these discrepancies, I collated records from museum collections and wildlife databases. These data clearly indicate that stated altitudinal limits for the species are not correct. The currently known southern limit of the species is near Eden, New South Wales (NSW). The distribution of the species was modelled using the DOMAIN climate matching algorithm. The model indicates that S. rueppellii may occur in East Gippsland, Victoria, suggests its likely occurrence in inland Queensland and northern NSW, but a low likelihood of occurrence in inland southern NSW. However, the data show strong spatial and temporal biases that restrict the confidence that may be placed in the model. It is argued that species distributions must be regarded as open and evolving hypotheses.

Active and passive dispersal of Centroberyx affinis (Berycidae) and Gonorynchus greyi (Gonorynchidae) larvae on the Sydney shelf

2000 ◽  
Vol 51 (3) ◽  
pp. 229 ◽  
Author(s):  
Kimberley A. Smith
Keyword(s):  
Continental Shelf ◽  
Larval Stage ◽  
Shelf Break ◽  
Outer Shelf ◽  
Size Distributions ◽  
Passive Dispersal ◽  
Larval Size ◽  
Larval Behaviour ◽  
Eastern Australia ◽  
Spawning Periods

Distributions of small and large larvae of Centroberyx affinis (Berycidae) and Gonorynchus greyi (Gonorynchidae) were examined along a shore-normal transect across the Sydney continental shelf, south-eastern Australia during January and April 1994. Both species were abundant, and 3016 individuals of C. affinis and 3184 individuals of G. greyi were taken. Distributions of small and large C. affinis reflected hydrographic variability and suggested passive dispersal. Previous observations of high year-class variability for this species may therefore reflect oceanographic variability during the larval stage. In contrast, the distributions of G. greyi only partially reflected hydrography and appeared to be influenced by larval behaviour at both sizes. Size distributions during each month indicated protracted spawning periods for both species. Spawning by C. affinis may have occurred over the inner shelf although the location was unclear because of the complexity of nearshore currents. Spawning by G. greyi probably occurred over the outer shelf. An increasing influence of larval behaviour with larval size on the distribution of G. greyi restricted larger individuals to the shelf break; this may have been a response to higher productivity in this region.

scholarly journals Controlled thawing of foods

2000 ◽  
Vol 18 (No. 5) ◽  
pp. 194-200 ◽  
Author(s):  
K. Hoke ◽  
L. Klíma ◽  
R. Grée ◽  
M. Houška
Keyword(s):  
Power Level ◽  
Point Of View ◽  
Hot Water ◽  
Similar Process ◽  
Hot Air ◽  
Air Temperatures ◽  
The Mean ◽  
Level 1 ◽  
The Times ◽  
Mean Time

The various ways of thawing of model food made for comparison of these processes from point of view of duration. The experiments were conducted under condition that the surface temperature of the thawed food did not overcome 15°C. Shortest mean time of thawing was achieved for vacuum-steam thawing. Regarding to the regime chosen the time of thawing varied between 18.4–29 min. The similar process of vacuum thawing with steam generated from hot water placed below the food was also successful. For this process the mean time of thawing was predicted between 30.5 and 35 min. If the starting temperature of the water was below the boiling point at vacuum level in the chamber the time of thawing was much longer (about 49 min). For hot air thawing we have tested two regimes with temperature of air 50 and 70°C. For both air temperatures the times of thawing were similar being 52.1 and 53.6 min, respectively. Microwave thawing was depending on the power of microwave oven. The time of thawing was achieved 28.9 min at power level 1, at power level “thawing” the process duration was 34.4 min.

scholarly journals Sexual stages of the female portion in the scallop Nodipecten nodosus (Linné, 1758) and astaxanthin quantity in each stage

2010 ◽  
Vol 70 (3) ◽  
pp. 651-658 ◽  
Author(s):  
S. Sühnel ◽  
F. Lagreze ◽  
M. Bercht ◽  
JF. Ferreira ◽  
AL. Carneiro-Schaefer ◽  
...  
Keyword(s):  
Reproductive Cycle ◽  
Culture System ◽  
Female Gonad ◽  
Sexual Stage ◽  
Microscopic Evaluation ◽  
Female Part ◽  
Sexual Stages ◽  
One Year ◽  
Spawning Periods ◽  
Nodipecten Nodosus

This work describes the gametogenic cycle of the scallop Nodipecten nodosus kept in a culture system. To this end, during one year, samples were taken from the broodstocks every 30 days to be submitted to macroscopic and microscopic analyses and to measure the amount of astaxanthin. To perform the microscopic evaluation, 5 μ slices from the median portion of the female part of the gonad were submitted to the pattern methodology for histological analyses with paraffin and HE coloration. The remaining portion of the female gonad was lyophilised to extract and quantify the levels of astaxanthin using HPLC. The microscopic analyses revealed four well defined stages for the reproductive cycle. Analyses of data taken throughout the year indicated preferential spawning periods from December to January and from July to September. The astaxanthin analyses showed higher amounts of this carotenoid during the advanced pre-spawning and the initial spawning periods than during gametogenesis, initial pre-spawning, advanced spawning, and the spent stages. According to these results, it was possible to establish a descriptive table of the sexual stages of the female portion of the gonad and the amount of astaxanthin in the sexual stage of the scallop Nodipecten nodosus.

scholarly journals Age-dependent social learning in a lizard

2014 ◽  
Vol 10 (7) ◽  
pp. 20140430 ◽  
Author(s):  
Daniel W. A. Noble ◽  
Richard W. Byrne ◽  
Martin J. Whiting
Keyword(s):  
Social Learning ◽  
Group Living ◽  
Food Sources ◽  
Success Rates ◽  
Young Males ◽  
Association Task ◽  
Instrumental Task ◽  
Eastern Australia ◽  
Age Dependent ◽  
Dependent Learning

Evidence of social learning, whereby the actions of an animal facilitate the acquisition of new information by another, is taxonomically biased towards mammals, especially primates, and birds. However, social learning need not be limited to group-living animals because species with less interaction can still benefit from learning about potential predators, food sources, rivals and mates. We trained male skinks ( Eulamprus quoyii ), a mostly solitary lizard from eastern Australia, in a two-step foraging task. Lizards belonging to ‘young’ and ‘old’ age classes were presented with a novel instrumental task (displacing a lid) and an association task (reward under blue lid). We did not find evidence for age-dependent learning of the instrumental task; however, young males in the presence of a demonstrator learnt the association task faster than young males without a demonstrator, whereas old males in both treatments had similar success rates. We present the first evidence of age-dependent social learning in a lizard and suggest that the use of social information for learning may be more widespread than previously believed.

The Flatback Turtle, Chelonia depressa, in Queensland: Reproductive Periodicity, Philopatry and Recruitment

1984 ◽  
Vol 11 (3) ◽  
pp. 579 ◽  
Author(s):  
CJ Limpus ◽  
A Fleay ◽  
V Baker
Keyword(s):  
Breeding Season ◽  
Sea Turtles ◽  
Recruitment Rate ◽  
Southern Limit ◽  
Total Fecundity ◽  
Eastern Australia ◽  
Reproductive Life ◽  
Breeding Seasons ◽  
Remigration Interval ◽  
High Degree

The Bundaberg coast is the southern limit for reproduction by Chelonia depressa in eastern Australia. Here the species lays 2.84 � 0.78 (mean � SD) clutches per breeding season with a renesting interval of 15.99 � 1.89 days. When successful nesting does not occur on a nesting crawl the female returns after 1.17 � 1.07 d for another attempt. The mean remigration interval is 2.65 � 0.92 years and the average female is estimated to have a reproductive life of between 2.05 and 2.55 breeding seasons. The estimated annual recruitment rate of neonate nesting females into this colony is 27.2 � 10.8% of the population. The females return repetitively with a high degree of accuracy to the same small nesting beach within a single breeding season and in successive breeding seasons. The reproductive strategy of C. depressa compared with that of other sea turtles appears to involve an increase in hatchling size, to reduce predation, achieved by laying relatively large eggs. However, only a few small clutches are laid in a breeding season, so that seasonal fecundity for the species is low relative to that in other sea turtles such as C. mydas. Because its reproductive life is longer, C. depressa has a total fecundity only slightly less than that of C. mydas.

Effects of Artificial Propagation and the Weather on Recruitment in the Lake Ontario Whitefish Fishery

1963 ◽  
Vol 20 (3) ◽  
pp. 597-646 ◽  
Author(s):  
W. J. Christie
Keyword(s):  
Lake Trout ◽  
Lake Ontario ◽  
Climatic Conditions ◽  
Commercial Catch ◽  
Air Temperatures ◽  
Spawning Stock ◽  
Catch Statistics ◽  
The Times ◽  
One Year ◽  
Over Exploitation

No significant relationship could be found between variations in the level of fry planting and ensuing variations in the level of catch in the long-term statistics of the Lake Ontario whitefish gill-net fishery. An alternate-year planting experiment in which fry were planted in the even-numbered years 1944 through 1954, similarly failed to show a detectable level of contribution of the hatchery fish to the fishery. The supported year-classes averaged larger than those not given hatchery support but this was judged coincidental because of a phasing with an alternate-year periodicity which characterized the catch statistics over the whole series examined, and was present in the six years prior to the start of the alternate-year plantings. Estimates of spawning stock were calculated and it was not found that the progeny-per-parent ratios were significantly affected by the fry plantings.A possible explanation for the periodicity was suggested by a significant correlation between air temperatures at the times of spawning and hatching, and the strengths of the produced year-classes. Cold Novembers followed by warm Aprils appeared to provide conditions associated with the production of larger year-classes, with the opposite combinations relating to the weaker broods.The disappearance of lake trout and ciscoes from the commercial catch resulted in increased fishing pressure directed towards the capture of the whitefish. Increases in the efficiency and intensity of the fishing were observed during the period of the study and these were likely responsible for the reduction of the average age of the fish in the catch by almost one year, and the resultant restriction of the annual catch to one year-class in recent years. Probably because most of the fish are currently caught before first spawning, a decline in spawning stock was almost continuous during the study period. The year-to-year fluctuations in the level of the catch increased both because of the reduced average age, and because of a greater variation in year-class strength. The year-classes produced in favourable years tended to increase, down to quite low levels of stock. This gave a configuration similar to Ricker's Type C reproduction curve, and which differed chiefly in that the limiting diagonal representing minimum reproduction fell below the replacement diagonal. It was suggested that the whitefish may require more than one spawning, to achieve stock replacement. The present instability of the catch, and the potentially serious effect of any sustained break in the rhythm of the climatic conditions suggest a condition of over-exploitation in this case.

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