Metamorphosis of the final phyllosoma and secondary lecithotrophy in the puerulus of Panulirus cygnus George: a review

1997 ◽  
Vol 48 (8) ◽  
pp. 783 ◽  
Author(s):  
Paulette S. McWilliam ◽  
Bruce F. Phillips
Keyword(s):  
Energy Levels ◽  
Field Studies ◽  
Shelf Break ◽  
Energy Reserves ◽  
Specific Level ◽  
Larval Phase ◽  
Larval Recruitment ◽  
Panulirus Cygnus ◽  
Break Region ◽  
Nutritional Studies

The final phyllosoma of Panulirus cygnus metamorphoses to a non-feeding puerulus that lives on energy reserves accumulated in the final larva, and the metamorphic moult occurs mainly in the slope region adjoining the shelf-break off Western Australia. A review of the literature on field studies, laboratory rearing and nutritional studies of phyllosomal and other decapod zoeal larvae provided no evidence that metamorphosis in P. cygnus (or other shallow-water palinurids) is triggered by a direct environmental cue. It did indicate that metamorphosis results from the culmination of sustained nutrition and reserve energy levels through the later larval phase. Therefore, since the puerulus is secondarily lecithotrophic, it is considered that metamorphosis occurs only after the final phyllosoma has reached some critical, specific, level of stored energy reserves. Appropriate food for later larval development and successful metamorphosis of P. cygnus is more abundant in the shelf-break region (than further offshore) because this is a region of high plankton and micronekton biomass dominated by the Leeuwin Current. It also explains why metamorphosis occurs mainly in the shelf-break region. This review indicates research necessary for evaluation of the present interpretation and of larval recruitment processes in this species.

Temporal and spatial patterns of spawning in jack mackerel, Trachurus declivis (Pisces:Carangidae), during 1988-91 in eastern Tasmanian waters

1995 ◽  
Vol 46 (5) ◽  
pp. 831 ◽  
Author(s):  
A Jordan ◽  
G Pullen ◽  
J Marshall ◽  
H Williams
Keyword(s):  
Thermal Structure ◽  
Shelf Break ◽  
Eastern Coast ◽  
Jack Mackerel ◽  
Spatial And Temporal Patterns ◽  
Cold Event ◽  
Temporal And Spatial ◽  
High Concentrations ◽  
Break Region ◽  
Eggs And Larvae

Ichthyoplankton surveys conducted during the summer and autumn of 1988-89, 1989-90 and 1990-91 along the eastern coast of Tasmania were used to examine the spatial and temporal patterns of eggs and larvae of jack mackerel, Trachurus declivis. Results indicate that the species spawns along the entire eastern coast during summer. Trachurus declivis eggs were most abundant at shelf-break stations, indicating that spawning is concentrated in this region, although high concentrations of eggs were present on the inner shelf in 1988-89, which can be attributed to rapid onshore transport in that year. Larvae were evenly dispersed over the shelf, with the distribution of larval ages showing no indication of inshore recruitment. Considerable interannual differences in sea surface temperatures and vertical thermal structure were apparent, with the warmer waters and strong thermal stratification in the summer of 1988-89 resulting from the influx of subtropical East Australian Current (EAC) water onto the shelf, which corresponded with a major La Nina 'cold event' at that time. It is suggested that the distribution of spawning is unaffected by the interannual variations in oceanography as the mature population spawns in deeper water in the shelf-break region that is unaffected by the warming in surface waters.

Post-settlement energy reserves in Panulirus cygnus: experimental effects of starvation on survival and nutritional condition

2007 ◽  
Vol 153 (3) ◽  
pp. 445-456 ◽  
Author(s):  
A. J. Limbourn ◽  
R. C. Babcock ◽  
D. J. Johnston ◽  
P. D. Nichols ◽  
B. Knott
Keyword(s):  
Nutritional Condition ◽  
Energy Reserves ◽  
Panulirus Cygnus

Corrigendum to: Ocean currents and the larval phase of Australian western rock lobster, Panulirus cygnus

2002 ◽  
Vol 53 (3) ◽  
pp. 731 ◽  
Author(s):  
David A. Griffin ◽  
John L. Wilkin ◽  
Chris F. Chubb ◽  
Alan F. Pearce ◽  
Nick Caputi
Keyword(s):  
Transport Model ◽  
Early Stage ◽  
Larval Survival ◽  
Ocean Currents ◽  
Larval Transport ◽  
Offshore Wind ◽  
Larval Phase ◽  
Leeuwin Current ◽  
The North ◽  
Panulirus Cygnus

The return of Panulirus cygnus larvae to the coast of Western Australia after nearly a year at sea and its modulation by ocean currents were addressed with an individual-based larval-transport model. The simulations implied that offshore wind-driven transport of larvae is balanced by onshore geostrophic flow. Additional simulations revealed that vertical migration behaviour was essential to larval survival through its impact on advection. The six years simulated include two of high, two of low, and two of average puerulus settlement. The most robust interannual difference of the simulations was that, when coastal sea level was low and the Leeuwin Current was weak, more early-stage larvae were lost to the north and west under the influence of the wind. Conversely, many late-stage model larvae were carried south of the fishery in years when the Leeuwin Current was strong. The fraction of model larvae remaining or arriving offshore of the fishery and metamorphosing was essentially constant from year to year, so the variation in observed puerulus settlement was not explained by the model. The results imply that the nonadvective effects of fluctuations in the Leeuwin (e.g., on temperature and primary production) were primarily responsible for the high variation in natural settlement.

Ocean currents and the larval phase of Australian western rock lobster, Panulirus cygnus

2001 ◽  
Vol 52 (8) ◽  
pp. 1187 ◽  
Author(s):  
David A. Griffin ◽  
John L. Wilkin ◽  
Chris F. Chubb ◽  
Alan F. Pearce ◽  
Nick Caputi
Keyword(s):  
Transport Model ◽  
Early Stage ◽  
Larval Survival ◽  
Ocean Currents ◽  
Larval Transport ◽  
Offshore Wind ◽  
Larval Phase ◽  
Leeuwin Current ◽  
The North ◽  
Panulirus Cygnus

The return of Panulirus cygnus larvae to the coast of Western Australia after nearly a year at sea and its modulation by ocean currents were addressed with an individual-based larval-transport model. The simulations implied that offshore wind-driven transport of larvae is balanced by onshore geostrophic flow. Additional simulations revealed that vertical migration behaviour was essential to larval survival through its impact on advection. The six years simulated include two of high, two of low, and two of average puerulus settlement. The most robust interannual difference of the simulations was that, when coastal sea level was low and the Leeuwin Current was weak, more early-stage larvae were lost to the north and west under the influence of the wind. Conversely, many late-stage model larvae were carried south of the fishery in years when the Leeuwin Current was strong. The fraction of model larvae remaining or arriving offshore of the fishery and metamorphosing was essentially constant from year to year, so the variation in observed puerulus settlement was not explained by the model. The results imply that the nonadvective effects of fluctuations in the Leeuwin (e.g., on temperature and primary production) were primarily responsible for the high variation in natural settlement.

Crystal field studies of the Mn4+ energy levels in the perovskite, LaAlO3

2013 ◽  
Vol 35 (8) ◽  
pp. 1544-1548 ◽  
Author(s):  
A.M. Srivastava ◽  
M.G. Brik
Keyword(s):  
Crystal Field ◽  
Energy Levels ◽  
Field Studies
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