Reproductive strategy and growth of the crimson-spotted rainbowfish, Melanotaenia splendida fluviatilis (Castelnau) (Pisces : Melanotaeniidae) in south-eastern Queensland

1984 ◽  
Vol 35 (1) ◽  
pp. 75 ◽  
Author(s):  
DA Milton ◽  
AH Arthington
Keyword(s):  
Reproductive Cycle ◽  
Reproductive Strategy ◽  
Juvenile Fish ◽  
Water Levels ◽  
Juvenile Survival ◽  
Annual Reproductive Cycle ◽  
South Eastern ◽  
Coastal Streams

M. s. fluvlatilis has a well-defined annual reproductive cycle in south-eastern Queensland. Spawning is confined to October, November and December, with the peak in October, before the onset of summer floods and unpredictable water levels in coastal streams. Juvenile fish grow rapidly and reach maturity in the year following hatching. Growth in both sexes conforms to the von Bertalanfi model, but males grow faster and to larger sizes than females. Differences in the reproductive strategy of M. s. fluviatilis in southern Queensland and that of the more northern subspecies, M. s. splendida, may be related to the relative predictability of flooding, and hence to the probability of egg and juvenile survival, in the two areas. M. s. fluviatilis has low fecundity but the species is, nevertheless, abundant in suitable environments.

Reproductive strategy and growth of the Australian smelt, Retropinna semoni (Weber) (Pisces : Retropinnidae), and the olive perchlet, Ambassis nigripinnis (De Vis) (Pisces : Ambassidae), in Brisbane, south-eastern Queensland

1985 ◽  
Vol 36 (3) ◽  
pp. 329 ◽  
Author(s):  
DA Milton ◽  
AH Arthington
Keyword(s):  
Native Species ◽  
Juvenile Fish ◽  
Open Water ◽  
Water Levels ◽  
South Eastern ◽  
Large Populations ◽  
Coastal Streams ◽  
Littoral Vegetation ◽  
Suitable Habitats ◽  
Eggs And Larvae

The reproductive biology and growth of R. semoni and A. nigripinnis were studied in Brisbane, south- eastern Queensland, over a 20-month period (1981-1982). R. semoni began to breed in winter at water temperatures exceeding 15�C, reflecting its salmoniform affinities and temperate distribution. A. nigripinnis, a subtropical species of Indo-Pacific origin, required a period of rising temperature before breeding began in spring at 22�C. Both species concentrated their breeding activity into the months that precede summer storms and high, variable stream discharges, which can generate fluctuating water levels, destruction of weedbeds and instability of the stream substrate. Pre-flood spawning also occurs in three other small-bodied native species in the region, and appears to have adaptive value in the seasonally unstable environments of coastal streams. Dispersal of juvenile fish may be facilitated by rising water levels during summer months following spawning. R. semoni grew faster and to larger sizes than A. nigripinnis and growth of both species was adequately described by the von Bertalanffy equation. Male and female R. semoni and male A. nigripinnis live and breed for 2 years but female A. nigripinnis survive and may breed into their third year. These patterns of survivorship and reproduction are consistent with the contention that natural mortality is higher in open-water foragers such as R. semoni than in species like A. nigripinnis, which tends to forage amongst littoral vegetation and in mid-water. Differences in the sizes of eggs and larvae of the two species are also consistent with the probability that they experience different relative exposure to predation. These and other attributes, coupled with pre-flood spawning, enable both species to achieve large populations in suitable habitats within coastal streams, in spite of their relatively low fecundities.

Mechanisms underlying pituitary microvascular remodelling in thoroughbred horses during the annual reproductive cycle

2014 ◽  
Author(s):  
Angus Yeomans ◽  
Nichol Thompson ◽  
Jennifer Castle-Miller ◽  
David O Bates ◽  
Domingo Tortonese
Keyword(s):  
Reproductive Cycle ◽  
Annual Reproductive Cycle ◽  
Thoroughbred Horses

scholarly journals Proliferative and Apoptotic Pathways in the Testis of Quail Coturnix coturnix during the Seasonal Reproductive Cycle

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1729
Author(s):  
Sara Falvo ◽  
Luigi Rosati ◽  
Maria Maddalena Di Fiore ◽  
Federica Di Giacomo Russo ◽  
Gabriella Chieffi Baccari ◽  
...  
Keyword(s):  
Reproductive Cycle ◽  
Second Messengers ◽  
Reproductive Period ◽  
Annual Reproductive Cycle ◽  
Coturnix Coturnix ◽  
Immunohistochemistry Analysis ◽  
17Β Estradiol ◽  
Apoptotic Pathways ◽  
Camp And Cgmp ◽  
Activation Phase

The quail Coturnix coturnix is a seasonal breeding species, with the annual reproductive cycle of its testes comprising an activation phase and a regression phase. Our previous results have proven that the testicular levels of both 17β-estradiol (E2) and androgens are higher during the reproductive period compared to the non-reproductive period, which led us to hypothesize that estrogens and androgens may act synergistically to initiate spermatogenesis. The present study was, therefore, aimed to investigate the estrogen responsive system in quail testis in relation to the reproduction seasonality, with a focus on the molecular pathways elicited in both active and regressive quail testes. Western blotting and immunohistochemistry analysis revealed that the expression of ERα, which is the predominant form of estrogen receptors in quail testis, was correlated with E2 concentration, suggesting that increased levels of E2-induced ERα could play a key role in the resumption of spermatogenesis during the reproductive period, when both PCNA and SYCP3, the mitotic and meiotic markers, respectively, were also increased. In the reproductive period we also found the activation of the ERK1/2 and Akt-1 kinase pathways and an increase in second messengers cAMP and cGMP levels. In the non-reproductive phase, when the E2/ERα levels were low, the inactivation of ERK1/2 and Akt-1 pathways favored apoptotic events due to an increase in the levels of Bax and cytochrome C, with a consequent regression of the gonad.

Annual reproductive cycle of the greasyback shrimp Metapenaeus ensis in Ise Bay, Japan

2021 ◽  
Author(s):  
Fumihiro Yamane ◽  
Katsuyoshi Suitoh ◽  
Takuji Okumura ◽  
Kenji Toyota ◽  
Naoaki Tsutsui ◽  
...  
Keyword(s):  
Reproductive Cycle ◽  
Annual Reproductive Cycle ◽  
Metapenaeus Ensis ◽  
Ise Bay
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