Does male-only fishing influence reproductive success of the female spiny king crab, Paralithodes brevipes?

2007 ◽  
Vol 64 (4) ◽  
pp. 735-742 ◽  
Author(s):  
Taku Sato ◽  
Masakazu Ashidate ◽  
Tadao Jinbo ◽  
Seiji Goshima
Keyword(s):  
Reproductive Success ◽  
Laboratory Experiments ◽  
Reproductive Potential ◽  
Fertilization Rate ◽  
Reproductive Season ◽  
Female Size ◽  
Fishing Pressure ◽  
King Crab ◽  
Sperm Limitation

Male-only fishing for spiny king crab (Paralithodes brevipes) has likely impaired the reproductive success of the stock by decreasing the availability of sperm and (or) male mates. The reproductive success of females in fished populations in 2003 and 2004 was estimated based on female reproductive potential determined in laboratory experiments. Some females had no or partial clutches and showed a low fertilization rate. As female size decreased, the fertilization rate decreased and their clutches became small. These results suggest that mating was impaired by sperm limitation, because risk of sperm limitation increases throughout the reproductive season in fished populations, and smaller females tend to mate later in the reproductive season than larger females of this species. We compared the reproductive success between these years with different fishing pressures. In 2003, the total fishing pressure was high, therefore causing decreases in availability of sperm and males. This likely resulted in the reproductive success of females being lower in 2003 than in 2004.

High fishing intensity reduces females’ sperm reserve and brood fecundity in a eubrachyuran crab subject to sex- and size-biased harvest

2017 ◽  
Vol 74 (9) ◽  
pp. 2459-2469 ◽  
Author(s):  
Luis M Pardo ◽  
Marcela P Riveros ◽  
Juan Pablo Fuentes ◽  
Ramona Pinochet ◽  
Carla Cárdenas ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Reproductive Output ◽  
Sperm Storage ◽  
Female Size ◽  
Sperm Viability ◽  
Female Reproductive Success ◽  
Sperm Limitation ◽  
Chilean Populations

Abstract Size-selective male fisheries may result in sperm limitation whereby the number of sperm is insufficient to fertilize all oöcytes produced by females. In eubrachyuran crabs, females have seminal receptacles for sperm storage which may reduce the risk of sperm limitation over their lifetime. In this study on the commercially exploited eubrachyuran Metacarcinus edwardsii, we evaluate the sperm limitation hypothesis by measuring female reproductive success in five Chilean populations subjected to low or high fishing intensity. The quantity and viability of sperm stored by females was measured in each season and population, and related to resulting brood fecundity. Females’ sperm reserve was larger when fishing intensity was low than when it was high—paralleling previously demonstrated differences in males’ sperm reserve—and especially in the season before oviposition. Sperm viability was in general high (92%) and independent of fishing intensity. Mean brood fecundity adjusted to constant female size was about 60% greater under low compared with high fishing intensity. Thus, in M. edwardsii, population reproductive output could be depressed by male-biased fishing in spite of female sperm storage capability.

scholarly journals Fishery-induced changes in Norwegian red king crab (Paralithodes camtschaticus) reproductive potential

2013 ◽  
Vol 71 (2) ◽  
pp. 365-373 ◽  
Author(s):  
Ann Merete Hjelset
Keyword(s):  
Egg Production ◽  
Barents Sea ◽  
Reproductive Potential ◽  
Size Composition ◽  
Red King Crab ◽  
Paralithodes Camtschaticus ◽  
King Crab ◽  
Males And Females ◽  
Induced Changes ◽  
Individual Fecundity

Abstract Hjelset, A. M. 2014. Fishery-induced changes in Norwegian red king crab (Paralithodes camtschaticus) reproductive potential. – ICES Journal of Marine Science, 71: 365–373. The introduced red king crab (Paralithodes camtschaticus) in the Barents Sea supports a valuable fishery in northern Norway. In this paper, I examine the effect of the increased harvest rate and the recently added female quota on the potential egg production of the stock. The size ranges of males and females in the period 1995–2011 were recorded, and estimated stock abundance of ovigerous females and established individual fecundity parameters from 2000–2007 were used to assess the reproductive potential of the stock from 1995–2011. The upper size ranges of males and females decreased throughout the period studied, presumably mainly due to fishing. The change in size composition among ovigerous females and functional mature males, and the reduced mean individual fecundity in the stock seem to have had a negative effect on the potential egg production of the stock.

scholarly journals Lifetime reproductive success in a population of female red kangaroos Macropus rufus in the sheep rangelands of western New South Wales: Environmental effects and population dynamics

2004 ◽  
Vol 26 (1) ◽  
pp. 45 ◽  
Author(s):  
AD Bilton ◽  
DB Croft
Keyword(s):  
Population Dynamics ◽  
Reproductive Success ◽  
Environmental Conditions ◽  
New South ◽  
New South Wales ◽  
Reproductive Potential ◽  
Lifetime Reproductive Success ◽  
South Wales ◽  
Macropus Rufus ◽  
Initial Starting

Female reproductive success and the recruitment of offspring to the next generation are key components of animal population dynamics. With an annual commercial harvest of between 13 and 22% of the red kangaroo (Macropus rufus) population, it is increasingly important that these processes are understood. We used data on the reproductive success of 33 free-ranging female M. rufus on Fowlers Gap station in far western New South Wales to determine the expected lifetime reproductive success (LRS) of females within an unharvested population. We also designed a model to generate predictions about female LRS incorporating empirical relationships between a mother?s reproductive success and maternal age, environmental conditions and the sex and survivorship of a previous reproductive attempt. Results from observations on female LRS (calculated from annual weaning rates) and those generated by the model predict that female M. rufus on ?Fowlers Gap? wean, on average, 3.7 young in a lifetime (ranges 0 - 11 and 0 - 20, respectively); representing only 41% of their maximum reproductive potential. Manipulation of initial starting conditions allowed the effect of varying environmental conditions on female LRS to be explored. The condition of the environment when females commence breeding does not appear to significantly affect their overall lifetime reproductive output. However, the occurrence of drought does. Females experiencing two droughts in a lifetime did not live as long and weaned fewer offspring and grandoffspring (from their daughters) than those females experiencing only one drought in a lifetime. In addition to the adverse effect of drought on the reproductive success of female M. rufus in this study, we suggest that, given the relatively high and stable population densities of M. rufus on ?Fowlers Gap?, other mechanisms (acting primarily on juvenile survival) must exist which limit population growth.

Male reproductive behaviour and spawning success in a temperate zone goby, Coryphopterus nicholsi

1982 ◽  
Vol 60 (10) ◽  
pp. 2309-2316 ◽  
Author(s):  
Kathleen S. Cole
Keyword(s):  
Reproductive Success ◽  
Standard Length ◽  
Reproductive Behaviour ◽  
Reproductive Season ◽  
Temperate Zone ◽  
Testicular Development ◽  
Male Size ◽  
Size Standard ◽  
Highly Correlated ◽  
Spawning Success

Coryphopterus nicholsi is a temperate zone marine goby. In laboratory groups of fish, females preferentially spawn with dominant males; assessment of dominance appears to be based upon courting vigour. Male size (standard length) and dominance were often, but not always, highly correlated. In contrast, there was no consistent correlation between territorial quality and spawning success. Smaller males in laboratory groups did not court females or guard eggs. However, their behaviour and testicular development during the reproductive season suggest that they may engage in sneak spawning. Dominant males are more likely to successfully guard eggs against conspecific predators than are subordinate males, and hence females should have greater reproductive success if they choose dominant males for spawning partners.

scholarly journals What makes lady beetles effective natural enemies in preventative biological control?

2020 ◽  
Vol 21 ◽  
pp. 00018
Author(s):  
Natalia Belyakova ◽  
Yulia Polikarpova
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Reproductive Potential ◽  
Cost Effective ◽  
Ecological Knowledge ◽  
Female Size ◽  
Lady Beetles ◽  
Efficacy Assessment

Based on the reconsideration of traditional criteria for assessing the efficacy of natural enemies, the screening of coccinellids for preventative control of aphids was conducted. The result suggests that there is no causation between the female size (weight) and the reproductive potential of the tested species. Considering that size does not matter in preventative releases, it is more cost-effective to produce small lady beetles. Essential and non-essential ecological knowledge for the efficacy assessment is discussed.

Effect of Sea-Age on the Reproductive Potential of Atlantic Salmon (Salmo salar) in Eastern Canada

1989 ◽  
Vol 46 (12) ◽  
pp. 2210-2218 ◽  
Author(s):  
R. G. Randall
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Reproductive Potential ◽  
Female Size ◽  
Eastern Canada ◽  
Age Composition ◽  
Atlantic Salmon Salmo Salar ◽  
Egg Deposition ◽  
Different Populations ◽  
Spawning Run

Reproductive potential of Atlantic salmon (Salmo salar), defined as average eggs per fish in the spawning run, varied three-fold both within stocks over time and among stocks from different geographic areas. Eggs per spawner is a function of fecundity, sea-age, proportion of females, and female size; the latter three traits varied significantly among years for salmon in both the Miramichi and Restigouche Rivers, New Brunswick. Because all of the above traits are related to sea-age at maturity, eggs per spawner was significantly correlated with mean sea-age in both rivers (R2 = 0.88 and 0.61, respectively). Among 10 different populations in eastern Canada, reproductive potential was also correlated with sea-age; for mean sea-ages (MSA) ranging from 1.0 to 1.8 yr, reproductive potential (RP) was defined by the power regression: RP = 1831.26 MSA1.30 (R2 = 0.64 P < 0.05). Thus reproductive potential can be estimated for any population for which the sea-age composition of spawners is known. Assuming a target egg deposition rate of 2.4 × 104 eggs per hectare, required spawners varied inversely with reproductive potential among the 10 populations, from five spawners (MSA = 1.75 yr) to 16 spawners (MSA = 1.15 yr) per hectare.

scholarly journals The mode of ovulation in the Namaqua rock mouse, Micaelamys namaquensis

2013 ◽  
Vol 91 (11) ◽  
pp. 829-836 ◽  
Author(s):  
C.E. Relton ◽  
N.C. Bennett ◽  
K. Medger
Keyword(s):  
Reproductive Success ◽  
Social Factors ◽  
Reproductive Potential ◽  
Follicular Development ◽  
Corpora Lutea ◽  
Visual Contact ◽  
Plasma Progesterone ◽  
Specific Mode ◽  
Full Contact ◽  
Ovarian Size

The pattern of ovulation in mammals is generally considered to be either spontaneous or induced by copulation, with environmental and social factors playing a key role in determining the specific mode of ovulation that would maximize the reproductive potential of the species. This study aims to determine whether the Namaqua rock mouse (Micaelamys namaquensis (A. Smith, 1834)) is a spontaneous or induced ovulator. Females were divided into three treatments differing in the degree of contact with a male. Namely, seven control females had no contact with a male; a further seven separated females had only chemical, auditory, and visual contact with a male; whereas six females had intermittent periods of full contact with a vasectomized male. Ovarian size, follicular development, and plasma progesterone concentrations were compared between the three treatments. Penile morphology was also investigated. Corpora lutea were found in all three treatments and the penis was smooth without any ridges or spikes, indicating that M. namaquensis is a spontaneous ovulator. Interestingly, however, the presence of a male (physical as well as just visual and olfactory) positively affected ovarian size, ovulation, and plasma progesterone concentrations. This signifies that although M. namaquensis ovulates spontaneously, male contact significantly influences ovulation rate and ultimately reproductive success.

Male mate choice and male-male competition coexist in the humpback whale (Megaptera novaeangliae)

2002 ◽  
Vol 80 (4) ◽  
pp. 745-755 ◽  
Author(s):  
Alison S Craig ◽  
Louis M Herman ◽  
Adam A Pack
Keyword(s):  
Mate Choice ◽  
Reproductive Potential ◽  
Humpback Whale ◽  
Male Competition ◽  
Megaptera Novaeangliae ◽  
Reproductive Season ◽  
Humpback Whales ◽  
Male Mate Choice ◽  
Calving Rate ◽  
Male Mate

Male humpback whales (Megaptera novaeangliae) outnumber females on the winter grounds and compete physically for proximity to females. Analyses of identification photographs collected in Hawai'i from 1976 through 1995 and scan samples collected in 1998 showed that (i) reproductive potential (calving rate) for the following winter was greater for females without a calf than females with a calf, (ii) females without a calf were less likely to be found alone and more likely to be found in large pods than females with a calf, (iii) individual females were found in larger pods when without a calf than when with a calf, (iv) the probability of females with a calf being escorted by one or more males increased as the reproductive season progressed, and (v) head lunges occurred more commonly in all-adult pods than in pods containing a calf. We concluded that male humpback whales associate preferentially with females with high reproductive potential, that the attractiveness of individual females varies with their status (with a calf versus without a calf), that males become progressively less choosy over the course of the reproductive season as females without a calf become increasingly rare on the winter grounds, and that males expend more energy in competition over females without a calf than females with a calf.

Size influences male mating success in the alfalfa blotch leafminer (Diptera: Agromyzidae)

2001 ◽  
Vol 133 (5) ◽  
pp. 717-719 ◽  
Author(s):  
Arild Andersen ◽  
Jeremy N. McNeil
Keyword(s):  
Reproductive Success ◽  
Male Mating ◽  
Female Size ◽  
Larval Competition ◽  
Female Reproduction ◽  
Male Size ◽  
Female Life History ◽  
Males And Females ◽  
Alfalfa Blotch Leafminer ◽  
Agromyza Frontella

Male size is an important parameter in mate choice for many species and has been associated with such female life-history parameters as increased fecundity or fertility and larger progeny (Phelan and Baker 1986; Savalli and Fox 1998, 1999; Brown 1999). In the alfalfa blotch leafminer, Agromyza frontella (Rondani), intraspecific larval competition may significantly influence the size of both males and females (Quiring and McNeil 1984a). The influence of female size on female reproductive success has been studied (Quiring and McNeil 1984b, 1984c), but to date, no attention has been given to the possible effects of male size. The objectives of this study were to determine if differences in male size, the result of intraspecific larval competition, affected male longevity and reproductive success, as well as various parameters of female reproduction.

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