Spawning and fecundity of the western king prawn, Penaeus latisulcatus Kishinouye, in Western Australian Waters

1980 ◽  
Vol 31 (1) ◽  
pp. 21 ◽  
Author(s):  
JW Penn
Keyword(s):  
Spawning Season ◽  
Ovary Development ◽  
Southern Population ◽  
Spawning Frequency ◽  
Total Length ◽  
Australian Coastline ◽  
The Individual ◽  
Western Australian

The microscopic and macroscopic changes which occur during ovary development to spawning have been investigated for P. larisulcatus. The latter stages (3 and 4) of development and the act of spawning have been found to be confined to single intermoult periods, with spawning being possible during each of a series of consecutive intermoult periods. Fecundity was found to vary significantly with the size of the individual, with the number of eggs ranging from approximately 105000 (123 mm total length female) to 650000 (217 mm total length female) at each spawning. The use of an index of population fecundity in combination with estimates of spawning frequency to document spawning seasons is discussed. Using the population fecundity method the two northern populations have been shown to have a year round spawning season, with maximum spawning occurring from autumn to spring. while the southern population was shown to have shorter seasons over summer. A relationship between ovary development and temperatures in excess of 17�C is suggested as the probable cause of the differences in duration of spawning seasons along the Western Australian coastline.

scholarly journals Associated skeletal and dental remains of a fossil odontaspidid shark (Elasmobranchii: Lamniformes)from the Middle Eocene Lillebælt Clay Formation in Denmark

2013 ◽  
Vol 61 ◽  
pp. 37-46
Author(s):  
Bitten Bolvig Hansen ◽  
Gilles Cuny ◽  
Bo Wilhelm Rasmussen ◽  
Kenshu Shimada ◽  
Perri Jacobs ◽  
...  
Keyword(s):  
Middle Eocene ◽  
Low Energy ◽  
Tooth Morphology ◽  
Sea Floor ◽  
Energy Deposit ◽  
Total Length ◽  
The Individual ◽  
Clay Formation

A set of associated vertebrae and teeth of a fossil shark was collected from the lower Lutetian (Middle Eocene) part of the Lillebælt Clay Formation in Denmark. Its vertebral morphology indicates that the individual belongs to an odontaspidid lamniform shark. Although it is here identified as Odontaspididae indet., its tooth morphology suggests that the fossil shark possibly belongs to an undescribed taxon closely allied to Odontaspis or Palaeohypotodus. Based on comparisons with extant Odontaspis, the fossil individual possibly measured about 333 cm in total length. The disarticulated nature of the specimen in a low-energy deposit indicates that the shark carcass must have been lying on the sea floor for some time before its burial. The fossil individual was found along with a possible shed tooth of another indeterminate odontaspidid taxon.

scholarly journals Antisymmetric male genitalia in Western Australian populations of Mecyclothorax punctipennis (Coleoptera: Carabidae: Moriomorphini)

2015 ◽  
Vol 46 (4) ◽  
pp. 393-409 ◽  
Author(s):  
James K. Liebherr ◽  
Kipling W. Will
Keyword(s):  
Reproductive Tract ◽  
Small Population ◽  
Female Reproductive Tract ◽  
Individual Species ◽  
Eastern Australia ◽  
Differential Gene ◽  
The Individual ◽  
The Right ◽  
Population Demographic ◽  
Western Australian

Western Australian populations of Mecyclothorax punctipennis (MacLeay) exhibit chiral polymorphism for male genitalic asymmetry. The plesiomorphic genitalic enantiomorph, wherein the male aedeagal median lobe is left side superior when retracted in the abdomen, is rotated 180° to a right side superior position in 23% of males from Western Australia. Conversely, population samples from eastern Australia are monomorphic for the plesiomorphic left side superior condition. Western Australian population samples are significantly heterogeneous for the percentages of chirally reversed males, with right side superior frequencies ranging 0–58%. Conversely, asymmetry of the M. punctipennis female reproductive tract, wherein the apex of the bursa copulatrix is distally expanded toward the right side of the individual, is shown to be monomorphic within the species. Based on the vast disparity in frequencies of left versus right enantiomorphs among populations of Western Australian M. punctipennis, we hypothesize that population demographic factors related to very small population size and differential gene sampling via genetic drift could interact to establish populations fixed for the novel form. When such chiral genitalic substitutions are coupled with speciation, subsequent diversification stemming from that common ancestor would result in monophyletic lineages characterized by genitalic inversion. This hypothesis is corroborated by the sporadic occurrences of individual males with chirally inverted genitalia throughout the Carabidae, and the known occurrence of eight carabid taxa — individual species to diverse lineages — that are monomorphically characterized by male genitalic inversion.

Allometry and population structure of Nicolea uspiana (Polychaeta: Terebellidae)

2010 ◽  
Vol 90 (5) ◽  
pp. 877-883 ◽  
Author(s):  
A.R.S. Garraffoni ◽  
L.Q. Yokoyama ◽  
A.C.Z. Amaral
Keyword(s):  
Population Structure ◽  
East Coast ◽  
Morphometric Parameters ◽  
Size Frequency Distribution ◽  
Relative Growth ◽  
Total Length ◽  
Length Width ◽  
Males And Females ◽  
The Individual ◽  
Individual Size

The relative growth and population structure of the terebellid Nicolea uspiana were investigated in the intertidal zone of a rocky shore on the south-east coast of Brazil, from May 2006 to May 2007. Eight hundred and forty-seven individuals of N. uspiana were analysed: 391 males, 163 females, and 293 immatures. Although significant differences in some morphometric parameters were found, there was no sexual dimorphism between males and females. There were differences in total length, width of segment 5, and length of the notopodial region between matures and immatures. The negative allometry of the total length in relation to five other parameters showed that this feature is a good measure for estimating the individual size, which was then used in the analysis of population structure. This population of N. uspiana showed a bimodal size–frequency distribution, with immature and mature individuals found during the entire year. This pattern indicates continuous reproduction, with each cohort growing for at least three to four months and being responsible for two consecutive settlement peaks.

scholarly journals The 2011 marine heat wave off southwest Australia

2012 ◽  
Vol 9 (2) ◽  
pp. 1691-1703 ◽  
Author(s):  
T. H. Rose ◽  
D. A. Smale ◽  
G. Botting
Keyword(s):  
Dissolved Oxygen ◽  
Heat Wave ◽  
Extreme Events ◽  
Algal Blooms ◽  
Multiple Use ◽  
Short Term ◽  
Oxygen Levels ◽  
Australian Coastline ◽  
Western Australian ◽  
Marine Heat Wave

Abstract. Over 2000 km of Western Australian coastline experienced a significant marine heat wave in February and March 2011. Seawater temperature anomalies of +2–4 °C were recorded at a number of locations and satellite-derived SSTs were the highest on record. Here, we present seawater temperatures from southwestern Australia and describe, in detail, the marine climatology of Cockburn Sound; a large, multiple-use coastal embayment. We compared temperature and dissolved oxygen levels in 2011 with data from routine monitoring conducted from 2002–2010. A significant warming event, 2–4 °C in magnitude, persisted for >8 weeks, and seawater temperatures at 10 to 20 m depth were significantly higher than those recorded in the previous 9 yr. Dissolved oxygen levels were depressed at most monitoring sites, being ~2 mg l−1 lower than usual in early March 2011. Ecological responses to short-term extreme events are poorly understood, but evidence from elsewhere along the Western Australian coastline suggests that the heat wave was associated with high rates of coral bleaching, fish, invertebrate and macroalgae mortalities, and algal blooms. However, more ecological information from Cockburn Sound and other multiple-use embayments is urgently needed. The 2011 heat wave provided insights into conditions that may become more prevalent in Cockburn Sound, and elsewhere, if the intensity and frequency of short-term extreme events increases as predicted.

scholarly journals REPRODUCTION BIOLOGY OF TRUE PERCULA CLOWN FISH Amphiprion percula IN HATCHERY

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Ketut Maha Setiawati ◽  
Gunawan Gunawan ◽  
Jhon Harianto Hutapea
Keyword(s):  
Economic Value ◽  
Ornamental Fish ◽  
Hatching Rate ◽  
Spawning Period ◽  
Spawning Frequency ◽  
Amphiprion Percula ◽  
Total Length ◽  
Reproduction Biology

<p>True percula clown fish (Amphiprion percula) is one of marine ornamental fish with high economic value and can spawn throughout the year in an aquarium. The aims of this research were to understand reproduction aspects of true percula clown fish broodstock in an aquarium. A pair of broodstock used in this experiment were 4-9 cm in total length and maintained in an aquarium of 60x40x30 cm3 dimension. Numbers of brrodstock were 18 pairs and each aquarium filled with one pair of broodstock. During the experiment, fish were fed with artificial feed first and one hour later with mysids shrimp and copepod until satiation twice a day. Parameters observed were broodstock size, numbers and hatching rate of eggs. The results showed, the size of spawned female were range from 6.6-9.5 cm and male from 4.6-6.2 cm. Average of eggs produced per spawning was varied 423±255 with the average of spawning frequency was 2.78±0.38 times/month. Broodstock was spawn partially with the maximum spawning frequency of single broodstock was 4 times/month. The biggest female with size of 9.5 cm was still productive and spawn 3 times/month. There was a pair of broodstock which can produce more than 700 eggs/spawning. This results indicated that true percula clown fish can spawn throughout the year in the aquarium with varied of eggs number and spawning frequency for each individual and spawning period. The average of hatching rate during the experiment was 79.72±13.73 % with range between first to the next spawning 0f 7-14 day.</p><p>Keywords: reproduction, true percula clown fish, Amphiprion percula, hatching rate</p>

Greenland halibut (Reinhardtius hippoglossoides) spawn annually but successive cohorts of oocytes develop over 2 years, complicating correct assessment of maturity

2011 ◽  
Vol 68 (2) ◽  
pp. 201-209 ◽  
Author(s):  
James Kennedy ◽  
Agnes C. Gundersen ◽  
Åge S. Høines ◽  
Olav S. Kjesbu
Keyword(s):  
Time Scale ◽  
Large Range ◽  
Spawning Season ◽  
Ovary Development ◽  
Greenland Halibut ◽  
Greenland Halibut Reinhardtius Hippoglossoides ◽  
Reinhardtius Hippoglossoides

Ovary development in Greenland halibut ( Reinhardtius hippoglossoides ) is complex, with several cohorts of developing oocytes present during vitellogenesis; this is unusual for a determinate spawner. There are also speculations that Greenland halibut are not capable of spawning every year. To investigate this possibility, ovaries from Greenland halibut caught throughout the year were examined histologically, and successive cohorts of oocytes were tracked through development. Results showed that the initial maturation of the ovaries from immature to spawning takes more than 1 year. The ovary initially develops as far as early vitellogenesis; however, the time scale for this is unclear. During the final year of development, the cohort of vitellogenic oocytes splits to form two cohorts; the larger cohort increases in size and is spawned in the coming spawning season. The smaller cohort also continues to develop, but at a much lower rate, in preparation for development for spawning in the following year. Within each month, there is a large range of oocyte sizes between fish; this leads to the extended spawning season that is known in many populations of this species. This complicates the assessment of maturity, and a more accurate microscopic maturity scale is proposed.

scholarly journals Studies on the Gonadosomatic Index and Fecundity of Mystus gulio (Ham.)

2013 ◽  
Vol 19 (2) ◽  
pp. 161-166 ◽  
Author(s):  
MA Islam ◽  
M Begum ◽  
HK Pal ◽  
MJ Alam
Keyword(s):  
Body Weight ◽  
Sex Ratio ◽  
Body Length ◽  
Gonadosomatic Index ◽  
Spawning Season ◽  
Gonad Weight ◽  
Total Length

The study was conducted for a period of twelve months from January to December 2006 to determine the gonadosomatic index (GSI) and fecundity of Mystus gulio. Total 370 of Mystus gulio were examined during the study period. The sex ratio (male:female) of the investigated fish was 1:1.22 and generally female was larger than male. The fish was found to have a wide spawning season (March to November) with a single spawning peak in July as indicated by the gonadosomatic index and ova diameter. Fecundity of the fish was ranged from 3,891 to 1,68,358 with an average of 32,909.49 during the period of study and was found to increase with the increase of body length and weight. The relationships between fecundity and total-length, body-weight, gonad-length and gonad-weight were found linear and statistically highly significant (p<0.05).DOI: http://dx.doi.org/10.3329/pa.v19i2.16957 Progress. Agric. 19(2): 161 - 166, 2008

scholarly journals A comparison of southern hemisphere breeding stock 'D' humpback whale population estimates from two key locations along the Western Australian coast

2019 ◽  
Author(s):  
Curt Jenner ◽  
Micheline Jenner ◽  
Chandra Salgado Kent ◽  
Phil J Bouchet ◽  
Rebecca Dunlop ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Humpback Whales ◽  
Population Estimates ◽  
Breeding Stock ◽  
North West ◽  
Shark Bay ◽  
Monitoring Strategies ◽  
Current Survey ◽  
Australian Coastline ◽  
Western Australian

This report aims to compare recent population estimates of southern hemisphere breeding stock D humpback whales (Megaptera novaeangliae) based on data collected at two key locations along the Western Australian coastline, namely North West Cape (NWC) and Shark Bay, ~400 km south of NWC. The report additionally investigates the efficacy and practicality of current survey designs, and serves as a reference point for future improvement in whale monitoring strategies (location of surveys, field protocols, etc.).

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