The influence of age on reproductive success and diet in Australasian gannets (Morus serrator) breeding at Pope's Eye, Port Phillip Bay, Victoria

2007 ◽  
Vol 55 (5) ◽  
pp. 267 ◽  
Author(s):  
T. M. Pyk ◽  
A. Bunce ◽  
F. I. Norman
Keyword(s):  
Reproductive Success ◽  
Food Availability ◽  
Fish Species ◽  
Breeding Success ◽  
Breeding Period ◽  
Chick Growth ◽  
Jack Mackerel ◽  
Commercial Fish ◽  
Red Mullet ◽  
Morus Serrator

The influence of age on reproductive success and diet was examined in ‘old’ (experienced; 12 years and older) and ‘young’ (5–8 years of age) Australasian gannets (Morus serrator) breeding at Pope’s Eye, Port Phillip Bay, Victoria during the 2002–2003 breeding period. Although food availability, as indicated by commercial fish catches, throughout this breeding period was low, there were no significant differences in breeding success or chick growth between groups. Nevertheless, old birds tended to have higher reproductive success, replacing more lost eggs and fledging chicks of a greater mass. However, old birds also laid more eggs that failed to hatch. Five fish species, including jack mackerel (Trachurus declivis), barracouta (Thyrsites atun), redbait (Emmelichthys nitidus), anchovy (Engraulis australis) and red mullet (Upeneichthys vlamingii), were important in the gannet diet during this breeding period. There were no significant differences in dietary parameters, including range of species and size of prey, between old and young gannets, nor were there any differences between those of the chicks and their parents, suggesting that adults do not forage selectively for their chicks. This study showed that even during a period of presumed low food availability, when experienced (older) birds might be expected to have enhanced success, the differences between these and less experienced (younger) birds may not be apparent.

scholarly journals Migratory Dates, Breeding Phenology, and Reproductive Success of European Turtle Doves between Lowlands and Highest Breeding Habitats in North Africa

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Ismail Mansouri ◽  
Mohamed Mounir ◽  
Wafae Squalli ◽  
Laila Elhanafi ◽  
Mohamed Dakki ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Breeding Success ◽  
Breeding Site ◽  
Breeding Habitat ◽  
Breeding Period ◽  
Breeding Phenology ◽  
Climate Conditions ◽  
Turtle Dove ◽  
Beni Mellal ◽  
Low Altitude

The migratory time, breeding chronology, and reproductive success of the European turtle doves (Streptopelia turtur) were studied in Midelt as a high-altitude breeding habitat and Beni Mellal as a low-altitude breeding site from 2015 to 2018 in Morocco. Migration dates, breeding phenology, and breeding success were recorded from March to October for each season. As a result, during four years, arrival dates were earlier at the low breeding site, while departure dates were earlier at the high breeding site. Similarly, breeding phenology from nest building to fledging was early at low-altitude site. On the other hand, with four breeding seasons and 893 nests (467 at Midelt and 426 at Beni Mellal), average breeding success was 57% of chicks at Midelt compared to 60.15% at Beni Mellal. Moreover, at Midelt, 18.89% of eggs and 10.54% of chicks were predated, while at Beni Mellal 21.80% of eggs and 4.65% of chicks were deserted due to human disturbance. As a response, at Midelt breeding period was shorter and shifted to hot periods to ensure better reproductive success. Finally, our results highlight that the turtle dove breeding season is later and shorter at breeding highlands, which might allow this bird to avoid the vigorous climate conditions at mountains and their effect on reproductive success.

scholarly journals Patterns of Egg Laying and Breeding Success in Humboldt Penguins (Spheniscus Humboldti) at Punta San Juan, Peru

The Auk ◽  
2002 ◽  
Vol 119 (1) ◽  
pp. 244-250 ◽  
Author(s):  
Rosana Paredes ◽  
Carlos B. Zavalaga ◽  
Daryl J. Boness
Keyword(s):  
Reproductive Success ◽  
Breeding Success ◽  
Egg Laying ◽  
Lifetime Reproductive Success ◽  
Breeding Cycle ◽  
Breeding Period ◽  
San Juan ◽  
Unpredictable Environment ◽  
Second Clutch

Abstract We analyzed patterns of egg laying and breeding frequency of Humboldt Penguins (Spheniscus humboldti) between 1993 and 1997 at Punta San Juan, Peru. Egg-laying extended from mid-March to the first week of December, showing two well-defined peaks in April and August–September. The extended breeding period of these birds was the result of individuals having a second clutch. About half of the females (n =189) had two clutches per year, most of which were double broods (73%). The date of completion and outcome of reproduction, or whether a change of mates occurred from the previous year, did not affect timing of egg laying. The majority of first clutches (62%) were laid in April each year. Two-clutch breeders that started laying eggs early in April had a higher breeding success than those starting in late April, and double brooders had greater success than single brooders. Two-clutch breeders started to lay eggs earlier than single-clutch breeders. Taking into account that a penguin breeding cycle (from egg laying to fledging) lasts ∼4 months, laying eggs early in April increases the chance of rearing two successful broods per year. During three consecutive years, females tended to have two clutches instead of only one clutch and an average breeding success of 4.54 fledglings over 3 years. Having as many clutches as possible when conditions are favorable appears to be a strategy used by Humboldt Penguins to maximize their lifetime reproductive success within a productive but unpredictable environment.

Body shape and trawl cod end selectivity for nine commercial fish species

2003 ◽  
Vol 83 (6) ◽  
pp. 1309-1313 ◽  
Author(s):  
Zafer Tosunoğlu ◽  
Yeliz Doğanyilmaz Özbilgin ◽  
Hüseyin Özbilgin
Keyword(s):  
Fish Species ◽  
Body Shape ◽  
Morphological Characteristics ◽  
Mesh Size ◽  
Sea Bream ◽  
Merluccius Merluccius ◽  
Commercial Fish ◽  
Red Mullet ◽  
Common Pandora ◽  
Merlangius Merlangus

This study investigates the catch components of a commercially used demersal trawl cod end in Izmir Bay, and reveals some of the morphological characteristics of nine commercial fish species; red mullet (Mullus barbatus), hake (Merluccius merluccius), whiting (Merlangius merlangus euxinus), poor cod (Trisopterus minutus capelanus), tub gurnard (Trigla lucerna), common pandora (Pagellus erythrinus), axillary sea bream (Pagellus acarne), picarel (Spicara smaris) and annular sea bream (Diplodus annularis) in relation to mesh size and shapes. Furthermore selectivity of 40-mm polyethylene netting cod end for red mullet, hake, common pandora, axillary sea bream, picarel and annular sea bream is presented. The results are discussed in a way to understand the probable effects of fish body shape on mesh selectivity.

THE NUMBER AND QUALITATIVE CHARACTERISTICS OF FRY FISH IN SHALLOW COASTAL WATERS OF THE VOLGA IN THE SUMMER-AUTUMN PERIOD OF 2012

2017 ◽  
pp. 65-73
Author(s):  
Edward Vladimirovich Nikitin
Keyword(s):  
Fish Species ◽  
Coastal Waters ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
Volga River ◽  
Commercial Fish ◽  
Autumn Period ◽  
Fish Juveniles ◽  
Qualitative Characteristics ◽  
Shallow Coastal Waters

Shallow coastal waters of the Volga river is a flooded feeding area for fish juveniles of nonmigratory fish species. There takes place annual downstream migration of fluvial anadromous fish species from spawning grounds of the Volga river to the Northern Caspian Sea. The most important factors determining the number and qualitative characteristics of fry fishes are the level of the Caspian Sea (currently having a tendency to the lowering), hydrological and thermal regimes of the Volga river. Researches were carried out in definite periods of time. In the summer-autumn period of 2012 fry fishes were presented by 19 species (13 of them were commercial species), which belonged to 9 families. The article gives data on all the commercial fish species. In the first decade of July the maximum number of fry fish was registered in the western part of the Volga outfall offshore - in box 247 (19.86 mln specimens/km2), in the eastern part - in box 142 (20.4 mln specimens/km2). The most populous were roach, red-eye, silver bream and bream; size-weight characteristics were better in the areas remoted from the Volga delta. In the third decade of July the quantitative indicators of fry fish on these areas decreased, size-weight characteristics greatly increased. In the second decade of October in the western part of the seaside there were registered increased pre-wintering concentrations of fish juveniles, their qualitative indicators increased, which is evidence to favorable feeding conditions in 2012.

Caribbean Commission

1951 ◽  
Vol 5 (4) ◽  
pp. 810-811
Keyword(s):  
United Kingdom ◽  
Fish Species ◽  
Joint Meeting ◽  
Research Committee ◽  
Commercial Fish ◽  
The United Kingdom ◽  
Trawl Fishing ◽  
The Caribbean

A joint meeting of the Research Committee on Agriculture, Fish, Wildlife and Forestry and the Preparatory Fisheries Committee was held in Trinidad on July 9, 1951. The meeting, under the chairmanship of the United Kingdom representative (Frampton), discussed proposals regarding commercial trawl fishing in the Gulf of Paria and the organization of the Fisheries Conference. The committee felt that a survey of commercial trawl fishing should be undertaken at an estimated expense of $2,000. The committee also recommended that the Fisheries Conference, to be held in March 1952 for five days, should meet in Trinidad and have an agenda as follows: occurrence and distribution of commercial fish species in the Caribbean, techniques used in the Caribbean for fish capture, types of fishing craft used, marketing, storing, distribution, conserving methods, and cultivation of fish in ponds.

scholarly journals Evaluation of Trace Metal Levels in Tissues of Two Commercial Fish Species in Kapar and Mersing Coastal Waters, Peninsular Malaysia

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Fathi Alhashmi Bashir ◽  
Mohammad Shuhaimi-Othman ◽  
A. G. Mazlan
Keyword(s):  
Trace Metal ◽  
Fish Species ◽  
Coastal Waters ◽  
Positive Association ◽  
Peninsular Malaysia ◽  
International Standards ◽  
Metal Concentrations ◽  
Commercial Fish ◽  
Metal Levels ◽  
The Relationship

This study is focused on evaluating the trace metal levels in water and tissues of two commercial fish species Arius thalassinus and Pennahia anea that were collected from Kapar and Mersing coastal waters. The concentrations of Fe, Zn, Al, As, Cd and Pb in these coastal waters and muscle, liver and gills tissues of the fishes were quantified. The relationship among the metal concentrations and the height and weight of the two species were also examined. Generally, the iron has the highest concentrations in both water and the fish species. However, Cd in both coastal waters showed high levels exceeding the international standards. The metal level concentration in the sample fishes are in the descending order livers > gills > muscles. A positive association between the trace metal concentrations and weight and length of the sample fishes was investigated. Fortunately the level of these metal concentrations in fish has not exceeded the permitted level of Malaysian and international standards.

Hepatic levels of metal and metallothioneins in two commercial fish species of the Northern Iberian shelf

2008 ◽  
Vol 391 (1) ◽  
pp. 159-167 ◽  
Author(s):  
Denise Fernandes ◽  
Maria João Bebianno ◽  
Cinta Porte
Keyword(s):  
Fish Species ◽  
Commercial Fish
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