scholarly journals Behaviour of aggregated grey nurse sharks Carcharias taurus off eastern Australia: similarities and differences among life-history stages and sites

2015 ◽  
Vol 27 (1) ◽  
pp. 69-85 ◽  
Author(s):  
KR Smith ◽  
C Scarpaci ◽  
BM Louden ◽  
NM Otway
Keyword(s):  
Life History ◽  
Life History Stages ◽  
Eastern Australia ◽  
Similarities And Differences ◽  
Carcharias Taurus ◽  
Nurse Sharks

scholarly journals Does the grey nurse shark (Carcharias taurus) exhibit agonistic pectoral fin depression? A stereo-video photogrammetric assessment off eastern Australia

2016 ◽  
Vol 22 (1) ◽  
pp. 3
Author(s):  
Kirby R. Smith ◽  
Carol Scarpaci ◽  
Brett M. Louden ◽  
Nicholas M. Otway
Keyword(s):  
Sampling Methods ◽  
Pectoral Fin ◽  
Nurse Shark ◽  
Management Guidelines ◽  
Life History Stages ◽  
Stereo Video ◽  
Eastern Australia ◽  
Wide Range ◽  
Stereo Photogrammetry ◽  
Carcharias Taurus

Underwater stereo-video photogrammetry was used to document the pectoral fin positions of various life-history stages of the critically endangered east Australian population of the grey nurse shark (Carcharias taurus) during normal swimming behaviour at multiple aggregation sites. A wide range in pectoral fin positions was recorded with dihedral pectoral fin angles ranging from –25 to 88°. Pectoral fin angles varied significantly among sites and this was attributed to the differing navigational and energetic requirements of the sharks. There was no significant relationship between pectoral fin angles and distances separating the shark and scuba diver. The wide range in pectoral fin angles, interactive use of the fins during swimming, low-energy behaviours of the sharks at aggregation sites and absence of ‘fight’ response agonistic behaviour indicated that the species does not exhibit agonistic pectoral fin depression. Reports of agonistic pectoral fin depression in the grey nurse shark obtained with visual estimates should be treated as preliminary observations requiring further testing using accurate sampling methods such as stereo photogrammetry. It is important that diver compliance with existing management guidelines that prohibit divers from chasing or harassing grey nurse sharks and blocking cave and gutter entrances is maintained.

The flooding tolerance of two critical habitat-forming wetland shrubs, Leptospermum lanigerum and Melaleuca squarrosa, at different life history stages

2018 ◽  
Vol 66 (7) ◽  
pp. 500 ◽  
Author(s):  
Georgina Zacks ◽  
Joe Greet ◽  
Christopher J. Walsh ◽  
Elisa Raulings
Keyword(s):  
Life History ◽  
Seedling Growth ◽  
Seedling Establishment ◽  
Reference Sites ◽  
Crown Condition ◽  
Growth And Survival ◽  
Life History Stages ◽  
Eastern Australia ◽  
The Common ◽  
Study Species

Understanding the effect of water regime on the different life history stages of woody wetland plants is essential to managing their persistence. The common and widespread myrtaceous shrub species, Melaleuca squarrosa Donn. ex Sm. and Leptospermum lanigerum (Aiton) Sm., provide habitat for two critically endangered fauna within the Yellingbo Nature Conservation Reserve (south-eastern Australia), but are in decline putatively because of the altered flooding regimes. We, thus, tested the effects of flooding depth and duration on their seed germination and seedling establishment, and seedling growth and survival in two separate glasshouse experiments. We also compared the condition of mature plants of both species at an intermittently flooded (reference) site, and two near permanently flooded (impact) sites. Seeds of both species were able to germinate underwater, but early flooding reduced seedling establishment. Seedling growth of both species was greater in waterlogged than in well drained or inundated conditions, whereas no seedlings of either species survived >8 weeks of submergence. Leptospermum lanigerum seedlings were generally more flood tolerant than were M. squarrosa seedlings. Correspondingly, crown condition of mature M. squarrosa, but not L. lanigerum, was poorer at impact than reference sites. Prolonged flooding in swamp forests is likely to (1) limit woody plant recruitment, because flooding reduces seedling establishment, growth and survival, and (2) be deleterious to the maintenance of less flood-tolerant species (e.g. M. squarrosa). Moist exposed substrate is likely to be best for promoting the recruitment of both study species, and intermittent flooding for maintaining adult M. squarrosa plants.

Taxonomic position of two crimson-spotted rainbowfish, Melanotaenia duboulayi and Melanotaenia fluviatilis (Pisces : Melanotaeniidae), from eastern Australia, with special reference to their early life-history stages

1986 ◽  
Vol 37 (3) ◽  
pp. 385 ◽  
Author(s):  
LELM Crowley ◽  
W Ivantsoff ◽  
GR Allen
Keyword(s):  
Life History ◽  
Early Life ◽  
Recent Literature ◽  
New South ◽  
Single Species ◽  
Early Life History ◽  
Life History Stages ◽  
South Wales ◽  
Eastern Australia ◽  
Melanotaenia Duboulayi

In recent literature, the crimson-spotted rainbowfish from eastern Australia, M. fluviatilis, is recognized as a single species or subspecies. The present paper includes a study of early life-history stages, which shows that two species are represented: M. duboulayi (Castelnau) from eastern or coastal drainage systems of northern New South Wales and southern Queensland, and M. fluviatilis (Castelnau) of the inland Murray-Darling system.

Distribution and life history of caridean shrimps in regulated lowland rivers in southern Australia

2004 ◽  
Vol 55 (3) ◽  
pp. 295 ◽  
Author(s):  
A. J. Richardson ◽  
J. E. Growns ◽  
R. A. Cook
Keyword(s):  
Life History ◽  
Life Stages ◽  
Lowland Rivers ◽  
Flow Alteration ◽  
Eastern Australia ◽  
History Of ◽  
Paratya Australiensis ◽  
Juvenile Stages ◽  
Shrimp Abundance ◽  
Large Adult

Caridean shrimps are an integral component of lowland river ecosystems in south-eastern Australia, but their distributions may be affected by flow alteration. Monthly shrimp samples were collected from slackwaters in three hydrologically distinct sections of the heavily regulated Campaspe River and the less regulated Broken River for three consecutive years. The distributions of Paratya australiensis, Caridina mccullochi and Macrobrachium australiense, along with their life history in river sections with different hydrology are outlined. Paratya australiensis and M. australiense occurred in all sections, but C. mccullochi was absent from sections of the Campaspe River that received irrigation flows during summer/autumn. Shrimp larvae were most abundant in summer (December–February) and juvenile recruitment continued through to mid autumn (April). Breeding and recruitment of P. australiensis occurred for longer than other shrimps. Apart from large adult and berried M. australiense, all life stages of shrimps commonly occurred in slackwaters, particularly the larval and juvenile stages. Irrigation flows in summer/autumn probably adversely affect the size, extent and arrangement of slackwaters, at a time when they may be critical habitats for C. mccullochi larval development and recruitment. Dams and weirs in the Campaspe River may have influenced shrimp abundance and the timing of breeding.

scholarly journals The movement ecology of seagrasses

2014 ◽  
Vol 281 (1795) ◽  
pp. 20140878 ◽  
Author(s):  
Kathryn McMahon ◽  
Kor-jent van Dijk ◽  
Leonardo Ruiz-Montoya ◽  
Gary A. Kendrick ◽  
Siegfried L. Krauss ◽  
...  
Keyword(s):  
Life History ◽  
Clonal Growth ◽  
Movement Ecology ◽  
Future Research ◽  
The Novel ◽  
Long Distance ◽  
Spatial And Temporal Scales ◽  
Life History Stages ◽  
Research Areas ◽  
Time Movement

A movement ecology framework is applied to enhance our understanding of the causes, mechanisms and consequences of movement in seagrasses: marine, clonal, flowering plants. Four life-history stages of seagrasses can move: pollen, sexual propagules, vegetative fragments and the spread of individuals through clonal growth. Movement occurs on the water surface, in the water column, on or in the sediment, via animal vectors and through spreading clones. A capacity for long-distance dispersal and demographic connectivity over multiple timeframes is the novel feature of the movement ecology of seagrasses with significant evolutionary and ecological consequences. The space–time movement footprint of different life-history stages varies. For example, the distance moved by reproductive propagules and vegetative expansion via clonal growth is similar, but the timescales range exponentially, from hours to months or centuries to millennia, respectively. Consequently, environmental factors and key traits that interact to influence movement also operate on vastly different spatial and temporal scales. Six key future research areas have been identified.

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