Reproductive biology of the Patagonian bobtail squid, Semirossia patagonica (Sepiolidae: Rossiinae) in the south-west Atlantic

2008 ◽  
Vol 88 (5) ◽  
pp. 1019-1023 ◽  
Author(s):  
Bahadir Önsoy ◽  
Vladimir Laptikhovsky ◽  
Alp Salman
Keyword(s):  
Egg Size ◽  
Mature Female ◽  
Mature Male ◽  
Female Size ◽  
Male Size ◽  
East Atlantic ◽  
Potential Fecundity ◽  
North East ◽  
South West ◽  
Continuous Reproduction

A total of 104 Semirossia patagonica were collected all over the Patagonian shelf between the depths of 47 and 295 m. Mature female size varied from 10 to 35 mm ML, mature male size was 16–32 mm. Potential fecundity ranged between 527–766 eggs in pre-spawning females, ripe egg size was 3.4–5.0 mm. The oviduct capacity probably was no more than 30 eggs. The maximum number of spermatophores in males was 229. Males transfer 2–19 spermatophores to females during copulation. The ovulation pattern is asynchronous, individual spawning is continuous. Reproduction occurs all year round. Semirossia patagonica is a south-west Atlantic ecological sibling of north-east Atlantic bobtail squids Sepiola spp. and Sepietta spp.

scholarly journals Pipefish embryo oxygenation, survival, and development: egg size, male size, and temperature effects

2019 ◽  
Vol 30 (5) ◽  
pp. 1451-1460 ◽  
Author(s):  
Malin Nygård ◽  
Charlotta Kvarnemo ◽  
Ingrid Ahnesjö ◽  
Ines Braga Goncalves
Keyword(s):  
Egg Size ◽  
Care Quality ◽  
Offspring Size ◽  
Female Size ◽  
Male Size ◽  
Embryo Survival ◽  
Oxygen Levels ◽  
Syngnathus Typhle ◽  
Uniparental Care ◽  
Male Care

AbstractIn animals with uniparental care, the quality of care provided by one sex can deeply impact the reproductive success of both sexes. Studying variation in parental care quality within a species and which factors may affect it can, therefore, shed important light on patterns of mate choice and other reproductive decisions observed in nature. Using Syngnathus typhle, a pipefish species with extensive uniparental male care, with embryos developing inside a brood pouch during a lengthy pregnancy, we assessed how egg size (which correlates positively with female size), male size, and water temperature affect brooding traits that relate to male care quality, all measured on day 18, approximately 1/3, of the brooding period. We found that larger males brooded eggs at lower densities, and their embryos were heavier than those of small males independent of initial egg size. However, large males had lower embryo survival relative to small males. We found no effect of egg size or of paternal size on within-pouch oxygen levels, but oxygen levels were significantly higher in the bottom than the middle section of the pouch. Males that brooded at higher temperatures had lower pouch oxygen levels presumably because of higher embryo developmental rates, as more developed embryos consume more oxygen. Together, our results suggest that small and large males follow distinct paternal strategies: large males positively affect embryo size whereas small males favor embryo survival. As females prefer large mates, offspring size at independence may be more important to female fitness than offspring survival during development.

The Pennatulid Kophobelemnon stelliferum (Cnidaria: Octocorallia) in the Porcupine Seabight (north-east Atlantic Ocean)

1992 ◽  
Vol 72 (2) ◽  
pp. 417-434 ◽  
Author(s):  
A.L. Rice ◽  
P.A. Tyler ◽  
G.J.L. Paterson
Keyword(s):  
Growth Form ◽  
Marked Change ◽  
Seasonal Reproduction ◽  
Oocyte Diameter ◽  
East Atlantic ◽  
Bathymetric Range ◽  
Porcupine Seabight ◽  
North East ◽  
South West ◽  
Wet Weight

The upper bathyal sea-pen Kophobelemnon stelliferum extends to depths of about 1600 m in the Porcupine Seabight, to the south-west of Ireland, but is rare below about 1150 m. Photographic data suggest that the species attains numerical abundances of more than 2 m−2and a wet weight biomass of at least 4 g m−2. The highest densities, however, do not necessarily correspond to the highest biomass values since there is a clear depth-related change in population structure. The largest sea-pens are restricted to the deeper parts of the bathymetric range of the species. There is also a marked change in the growth form at a total colony length of about 250 mm, with larger colonies having relatively more polyps than smaller ones. The sexes are separate in Kophobelemnon stelliferum and the sex ratio of colonies is about 1:1. The maximum oocyte diameter is about 800 μm, but there is no evidence of seasonal reproduction by this pennatulid in the Porcupine Seabight.

Further results from a tagging study of pelagic sharks in the north-east Atlantic

1990 ◽  
Vol 70 (4) ◽  
pp. 707-720 ◽  
Author(s):  
J. D. Stevens
Keyword(s):  
Northern Spain ◽  
East Atlantic ◽  
North West ◽  
North East ◽  
The North ◽  
Isurus Oxyrinchus ◽  
South West ◽  
Predicted Values ◽  
Galeorhinus Galeus ◽  
South West England

A further 69 recaptures are reported from a tagging study of pelagic sharks initiated in 1970 in the north-east Atlantic. Galeorhinus galeus tagged in England were recaptured in the eastern Atlantic from southern Spain to north-west of Iceland. Among the 42 G. galeus recaptured the longest time at liberty was about 12 years and the greatest distance travelled was 2461 km. Among the 21 Prionace glauca recaptured the l ongest time at liberty was 10.7 years, and seven sharks moved distances between 4362 and 7176 km. One shark tagged in south-west England was recaptured in the South Atlantic off South America. An Isurus oxyrinchus was at liberty for 4–6 years and a Lamna nasus for up to about 13 years. Lamna nasus were recaptured from northern Norway to northern Spain. The growth rates of the tagged sharks were close to the predicted values for G. galeus, were slower for P. glauca and faster for L. nasus.

First results of shark tagging in the north-east Atlantic, 1972–1975

1976 ◽  
Vol 56 (4) ◽  
pp. 929-937 ◽  
Author(s):  
J. D. Stevens
Keyword(s):  
Adolescent Females ◽  
East Atlantic ◽  
Sport Fishery ◽  
North East ◽  
The North ◽  
Isurus Oxyrinchus ◽  
South West ◽  
First Results ◽  
South West England ◽  
Alopias Vulpinus

Since the early 1950s a sport fishery for sharks has existed off south-west England. On average some 5000 sharks are taken annually on rod and line between May and October. The catch consists almost entirely of blue sharks, the majority of which are immature or adolescent females, limited numbers of the porbeagle, Lamna nasus Bonnaterre, mako, Isurus oxyrinchus Rafinesque and very occasionally the thresher, Alopias vulpinus Bonnaterre.

scholarly journals Reproductive ecology and territorial behavior of Boana goiana (Anura: Hylidae), a gladiator frog from the Brazilian Cerrado

2021 ◽  
Vol 38 ◽  
pp. 1-12
Author(s):  
Tailise M. Dias ◽  
Cynthia P.A. Prado ◽  
Rogério P. Bastos
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Reproductive Ecology ◽  
Territorial Behavior ◽  
Female Size ◽  
Behavioral Strategies ◽  
Brazilian Cerrado ◽  
Male Size ◽  
Multiple Spawning ◽  
Low Incidence

Anuran males and females adopt different reproductive and behavioral strategies in different contexts. We investigated the reproductive ecology and territorial behavior of the treefrog Boana goiana (B. Lutz, 1968) from the Brazilian Cerrado. We hypothesized that competitor density/proximity would increase the behavioral responses of B. goiana males, and that mating would be assortative. We also tested if the number of eggs correlates with female size and if there is a trade-off between clutch size and egg size. We conducted two territoriality experiments to test the effects of male size, competitor proximity and competitor density. Larger males called more in the presence of a second male. In the second experiment, the largest males emitted more calls and the distance to the nearest male increased as resident males called more. In both experiments, the number of calls was influenced by either male size or spacing between males. Some males behaved as satellites, probably to avoid fights. Our analyses indicate that females choose males with similar sizes to their own, corroborating our hypothesis of size-assortative mating. We found no relationships between female size and clutch size/volume, and between egg size and number of eggs per clutch. We also report multiple spawning for this species. The low incidence of physical combats and the spacing pattern indicate that this species relies almost solely on calls to resolve contests, which could be explained by low motivation, or simply because males avoid combats to decrease injury risks. Thus, acoustic or even multimodal communication seems crucial for social interactions of B. goiana.

The challenges of asymmetric mating – the influence of male and female size on the reproductive output of Acanthochondria cornuta (Chondracanthidae)

Parasitology ◽  
2016 ◽  
Vol 143 (14) ◽  
pp. 1945-1953
Author(s):  
D. G. FRADE ◽  
S. NOGUEIRA ◽  
M. J. SANTOS ◽  
F. I. CAVALEIRO
Keyword(s):  
Egg Size ◽  
Reproductive Output ◽  
Reproductive Effort ◽  
Parasitic Copepod ◽  
Female Size ◽  
Male Size ◽  
Male And Female ◽  
Four Seasons ◽  
Egg Number ◽  
Potential Impact

SUMMARYThe reproductive strategy of Acanthochondria cornuta, a parasitic copepod with dwarf, hyperparasitic males, is described in detail. The potential impact of male parasitism on the reproductive output was evaluated by determining the size of each sex and the female's fecundity, egg size and total reproductive effort for each pair/trio throughout the four seasons of the year. Marked seasonal differences were observed in female size and reproductive output, suggesting two distinct generations, but no differences were observed for male size. No statistically significant correlations were observed between male size and any measure of reproductive effort, but females with larger males had lower fecundity. A trade-off between egg number and egg size was recorded. Overall, the reproductive effort in A. cornuta seems to be determined mostly by female size, and larger females do not hold smaller males.

The distribution of Ceratothoa steindachneri (Crustacea: Isopoda: Cymothoidae) parasitic in Echiichthys vipera in the north-east Atlantic

2002 ◽  
Vol 82 (3) ◽  
pp. 415-417 ◽  
Author(s):  
Tammy Horton ◽  
Beth Okamura
Keyword(s):  
Climate Change ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
South West ◽  
South West Coast ◽  
The 1960S ◽  
The Uk ◽  
Fish Hosts ◽  
Parasitic Isopod

The distribution of the recently discovered association of the parasitic isopod Ceratothoa steindachneri (Isopoda: Cymothoidae) with the lesser weever fish (Echiichthys vipera) is reported. Ceratothoa steindachneri appears to have colonized the south-west coast of the UK between the 1960s and the 1980s, possibly as a result of range expansion due to climate change. The occurrence of C. steindachneri in E. vipera from Arcachon, France, indicates that this association has been occurring for over 100 years. Our data confirm that C. steindachneri is able to parasitize a broad range of fish hosts.

The grouping of herring populations

1967 ◽  
Vol 47 (1) ◽  
pp. 193-208 ◽  
Author(s):  
D. H. Cushing
Keyword(s):  
Growth Rate ◽  
Seasonal Cycle ◽  
Egg Size ◽  
Reproductive Capacity ◽  
Production Cycle ◽  
East Atlantic ◽  
Late Autumn ◽  
North East ◽  
The North ◽  
Early Autumn

The work of Colebrook & Robinson (1965) has shown that there are three groups of seasonal cycle in production in the north-east Atlantic. There are three ‘races’ of herring in the same area, spawning in autumn, winter and spring. Taking the dates of spawning of each ‘race’ and the date by which the larvae must have food, a connexion can be made between the herring race and the production cycle in the area in which it lives. It is assumed that the date of spawning is fixed and does not vary with environmental conditions. Once the connexion between herring race and production cycle is made, certain comparisons can be made between races in growth rate, reproductive capacity and in the variability of recruitment. It was tentatively concluded that the magnitude of the year-class in the three north-east Atlantic races must be determined before metamorphosis. After metamorphosis, herring live on the beaches where the production cycle must have quite a different character.IntroductionHerring populations have been grouped as spring and autumn spawners ever since they have been examined scientifically. Autumn spawners have been further subdivided into early autumn (or summer) and late autumn (or winter) spawners (Johansen 1924). Since the discovery of sharp differences in fecundity and egg size between early and late autumn spav/ners (Polder & Zijlstra, 1959), the distinction between them has acquired the same status as that between autumn spawners and spring spawners. However, there are very marked differences between all three groups, and to relate them to then-calendar times of spawning it is proposed to name then ‘ autumn’ (formerly early autumn), ‘winter’ (formerly late autumn) and ‘spring’ spawners.

Egg size and fecundity in females of the subfamilies Todaropsinae and Todarodinae (Cephalopoda: Ommastrephidae)

1999 ◽  
Vol 79 (3) ◽  
pp. 569-570 ◽  
Author(s):  
V.V. Laptikhovsky ◽  
C.M. Nigmatullin
Keyword(s):  
Indian Ocean ◽  
West Africa ◽  
Egg Size ◽  
The South ◽  
Potential Fecundity ◽  
North West ◽  
East Pacific ◽  
South West ◽  
Wide Range ◽  
West Indian Ocean

Size of ripe eggs and potential fecundity are described in the squid of the subfamilies Todaropsinae and Todarodinae (Oegopsida: Ommastrephidae)—Todaropsis eblanae from West Africa, Todarodes angolensis from Namibia, Todarodes sagittatus from north-west Africa and the Mediterranean Sea, Todarodes sp. from the south-east Pacific, Nototodarus hawaiiensis from the south-east Pacific and West Indian Ocean and Martialia hyadesi from the south-west Atlantic. Females of both subfamilies are characterized by a wide range of ripe egg size (0.7–2.4 mm) and low and medium values of potential fecundity (20,000–2,500,000).

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