scholarly journals Variability in reproductive traits in the sex-changing fish, Coris julis, in the Mediterranean

2013 ◽  
Vol 15 (1) ◽  
pp. 106 ◽  
Author(s):  
A. ALONSO-FERNANDEZ ◽  
J. ALOS ◽  
M. PALMER
Keyword(s):  
Egg Size ◽  
Reproductive Output ◽  
Egg Quality ◽  
Stock Assessment ◽  
Seasonal Pattern ◽  
Reproductive Traits ◽  
Recreational Angling ◽  
The Mediterranean ◽  
First Time

The quantity and quality of propagules, i.e., reproductive output, play a key role in the dynamics of exploited populations, with particular implications for sex-changing fish. Here, we studied for the first time the effects of maternal traits on the reproductive output of the Mediterranean rainbow wrasse Coris julis, a sequential hermaphroditic fish widely distributed in temperate marine coastal regions. The quantity of the reproductive output (batch fecundity) was significantly related to maternal size, which is of special interest in a species submitted to size-selective harvesting (recreational angling). However, egg quality (egg size) was not significantly related to any maternal factor and the spawning fraction was related to a seasonal pattern only. These results should contribute to improving estimations of the annual reproductive output and the stock assessment of this species and some implications for management are discussed.

scholarly journals Reproductive traits of the gray ratsnake Ptyas korros from three geographically distinct populations

2012 ◽  
Vol 58 (6) ◽  
pp. 820-827 ◽  
Author(s):  
Long-Hui Lin ◽  
Fei Mao ◽  
Ce Chen ◽  
Xiang Ji
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Reproductive Output ◽  
Reproductive Traits ◽  
Egg Laying ◽  
Laying Date ◽  
Egg Mass ◽  
Size Number ◽  
Female Reproductive Traits ◽  
Clutch Mass

Abstract We collected gravid gray rat snakes Ptyas korros from three geographically distinct populations in China, Chenzhou (CZ), Jiangshan (JS) and Dinghai (DH), to study geographical variation in female reproductive traits. Egg-laying dates differed among the three populations such that at the most northern latitude egg-laying was latest, and earliest at the most southern lati-tutde. Clutch size, clutch mass, egg mass, egg shape, within clutch variability in egg sizes and relative clutch mass differed among the three populations, whereas post-oviposition body mass did not. Except for egg-laying date, none of the traits examined varied in a geographically continuous trend. CZ and DH females, although separated by a distance of approximately 1100 km as the crow flies, were similar in nearly all traits examined. JS females were distinguished from CZ and DH females by their higher fecundity (clutch size), greater reproductive output (clutch mass) and more rounded eggs. Our data do not validate the prediction that larger offspring should be produced in colder localities. The absence of an egg size-number trade-off in each of the three populations presumably suggests that P. korros is among species where eggs are well optimized for size within a population.

The effects of maternal size on clutch traits in a tropical invariant-clutch lizard, Carlia rubrigularis (Scincidae)

2006 ◽  
Vol 27 (4) ◽  
pp. 505-511 ◽  
Author(s):  
Brett Alexander Goodman
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Reproductive Output ◽  
Reproductive Traits ◽  
Theoretical Models ◽  
Offspring Size ◽  
Egg Mass ◽  
Egg Volume ◽  
Maternal Size ◽  
Tropical Australia

AbstractSpecies with an invariant or "fixed" clutch offer a unique opportunity to examine how variation in maternal size relates to key reproductive traits, such as egg size. Theoretical models of offspring size suggest selection should operate to optimize egg size and reproductive output. However, because invariant-clutch species are unable to allocate surplus resources to additional eggs (or offspring) they may exhibit different relationships than those anticipated under theoretical expectations. To test this, I examined relationships between maternal size-egg size in Carlia rubrigularis, an invariant-clutch producing scincid lizard from tropical Australia. C. rubrigularis exhibited relative clutch masses that were lower than variant clutch size species, but which were similar to other invariant clutch size species. However, maternal size (snout-vent length and post-oviposition mass) was correlated with several clutch traits (egg mass, egg width and egg volume), but females in better condition did not produce relatively heavier eggs. These results suggest mechanistic hypotheses may best explain the observed maternal size-egg size relationships in C. rubrigularis.

scholarly journals Sexual size dimorphism and female reproduction in the white-striped grass lizard Takydromus wolteri

2012 ◽  
Vol 58 (2) ◽  
pp. 236-243 ◽  
Author(s):  
Laigao Luo ◽  
Yilian Wu ◽  
Zhuyuan Zhang ◽  
Xuefeng Xu
Keyword(s):  
Egg Size ◽  
Reproductive Output ◽  
Sexual Size Dimorphism ◽  
Tail Length ◽  
Reproductive Traits ◽  
Life History Variation ◽  
Female Reproduction ◽  
Size Dimorphism ◽  
First Clutch ◽  
Female Reproductive Traits

Abstract Sexual size dimorphism (SSD) has long attracted the attention of biologists, and life-history variation is thought to play an important role in the evolution of SSD. Here we quantified SSD and female reproductive traits to identify potential associations between SSD and female reproduction in the white-striped grass lizard Takydromus wolteri. In a population from Chuzhou, China, the largest male and female were 53.0 mm and 57.5 mm in snout-vent length (SVL), respectively. Females were larger in SVL and abdomen length, whereas males were larger in head size and tail length. Females produced up to five clutches of eggs during the breeding season, with large females producing more clutches and more eggs per clutch than small ones. As a result, large females had a higher annual fecundity and reproductive output. Egg size was positively correlated with maternal SVL in the first clutch, but not in subsequent clutches. These results suggest that T. wolteri is a species with female-biased SSD, and that fecundity selection, in which large females have higher fecundity due to their higher capacity for laying eggs, is likely correlated with the evolution of SSD in this species [Current Zoology 58 (2): 236–243, 2012].

The Influence of The Introduced Tropical Alga Caulerpa Taxifolia, on the Biodiversity of the Mediterranean Marine Biota

1996 ◽  
Vol 76 (1) ◽  
pp. 235-237 ◽  
Author(s):  
D. Santini-Bellan ◽  
P.M. Arnaud ◽  
G. Bellan ◽  
M. Verlaque
Keyword(s):  
Reference Station ◽  
Marine Biota ◽  
Caulerpa Taxifolia ◽  
Structural Modifications ◽  
Physical Chemical ◽  
Similarity Indices ◽  
Quality Of Food ◽  
The Mediterranean ◽  
First Time

The Mediterranean proliferation of Caulerpa taxifolia provides an opportunity to examine the extent to which an introduced species can modify biodiversity. During 1992, benthic invertebrates were sampled in Roquebrune-Cap Martin area, at depths of 6 and 10 m, from a Caulerpa station and a reference station. Species richness is slightly lower at 6 m within Caulerpa while the number of specimens is much reduced at both depths. Similarity indices compare well between reference and Caulerpa stations.Caulerpa taxifolia, distributed in tropical seas, was recorded for the first time in the Mediterranean in 1984, as a single 1 m2 patch. This surface increased to 3 ha by 1990, 30 ha in 1991, 100 to 430 ha in 1992, and 1000 to 2000 ha at the end of 1993 (Meinesz & Hesse, 1991; Boudouresque & Meinesz, 1994).Maximum colonization is between 2 and 6 m depth, but the alga has been observed down to 99 m. Density can reach 350 m of fronds and 14,000 leaves per m2. Caulerpa taxifolia colonizes any type of substrate and invasion results in a drastic impoverishment of the algal components of the communities (Boudouresque et al., 1992; Verlaque & Fritayre, 1994). According to these authors, maximal poverty of communities coincides with the maximal development of C. taxifolia (summer-autumn) and epiflora is negligible, except during spring.These changes may induce functional and structural modifications of the fauna that lived in the communities before infestation. Invasion, particularly of photophilic algae and Posidonia beds (Ros et al., 1985), can modify quality and intensity of physical, chemical and hydrodynamical factors, number and quality of shelters, quantity and quality of food, and exchange of individuals between communities and populations.

scholarly journals Nutritional Quality of the European Spiny Lobster Palinurus elephas (J.C. Fabricius, 1787) (Achelata, Palinuridae) and the Non-Indigenous Northern Brown Shrimp Penaeus aztecus Ives, 1891 (Dendrobranchiata, Penaeidae)

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2480
Author(s):  
Thodoros E. Kampouris ◽  
Adamantia Asimaki ◽  
Dimitris Klaoudatos ◽  
Athanasios Exadactylos ◽  
Ioannis T. Karapanagiotidis ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Proximate Composition ◽  
Spiny Lobster ◽  
Brown Shrimp ◽  
Penaeus Aztecus ◽  
The Mediterranean ◽  
First Time ◽  
Established Species ◽  
Palinurus Elephas

The European spiny lobster is a species of great commercial value, yet a limited scientific knowledge exists on its biology, ecology, and physiology, especially for the stocks from east Mediterranean waters. The northern brown shrimp, a non-indigenous established species, is commercially exploited in regions of the Mediterranean Sea. Both species’ proximate composition and fatty acid profile were assessed for the first time in the Mediterranean region, exhibiting an overall significant statistical difference. Protein, fat, and energy contents were significantly higher in the northern brown shrimp, whereas moisture and ash contents were significantly higher in the European spiny lobster. The proximate composition for both species was well within the reported range for other lobster and prawn species in the Mediterranean Sea.

scholarly journals Phenotype variability of external quality traits of fertile eggs of partridge Italian bread in semi extensive breeding system

2013 ◽  
Vol 29 (3) ◽  
pp. 477-482
Author(s):  
V. Djermanovic ◽  
S. Mitrovic
Keyword(s):  
Breeding System ◽  
Egg Quality ◽  
Reproductive Traits ◽  
Shape Index ◽  
Quality Traits ◽  
External Quality ◽  
Extensive System ◽  
Length Width ◽  
Research Show

In this paper results of research of external quality traits of the fertile eggs of Partridge Italian bread in semi extensive system are shown. Research was conducted on sample of 64 eggs, divided in to two groups according to the weight. First group was eggs weighing up to the 60 g (? 60 g) and second group eggs weighing above 60 g (> 60 g). Aim of the research was to determine influence of the weight of the eggs to the external quality traits of fertile eggs, such as weight, length, width and shape index of the eggs in quoted breeding system. Obtained result points to the fact that Partridge Italian in semi extensive system achieves satisfying results in regard of the basic external characteristics of egg quality. Results of the conducted research show that it is needed to give higher attention to the quality of eggs used for planting, to the breeding direction, improvement of the productive and reproductive traits, and therefore to preservation of the genetic potential of different breeds and strains of chicken.

Is gonadal investment in walleye (Sander vitreus) dependent on body lipid reserves? A multipopulation comparative analysis

2008 ◽  
Vol 65 (4) ◽  
pp. 600-614 ◽  
Author(s):  
Matthew D Moles ◽  
Thomas A Johnston ◽  
Beren W Robinson ◽  
William C Leggett ◽  
John M Casselman
Keyword(s):  
Egg Size ◽  
Reproductive Effort ◽  
Reproductive Traits ◽  
Whole Body ◽  
Sander Vitreus ◽  
Lipid Concentration ◽  
Body Lipid ◽  
Lipid Contents ◽  
Nutrient Reserves

A key requirement of effective fisheries management is a better understanding of the mechanisms driving recruitment variability. Recent research suggests that the quantity and quality of gametes produced by fish is closely linked to the availability of surplus energy, usually stored as lipid. We sampled mature walleye (Sander vitreus) from seven populations across Canada to determine if indices of reproductive effort were positively related to indices of adult nutrient reserves, primarily body lipid concentration. Populations varied greatly in growth rates, body lipid contents, and reproductive traits. Within-population trends between indices of reproductive effort and parental body traits were highly variable. Body lipid concentration was most closely related to gonad lipid concentration, but not in all populations. Among populations, relative fecundity and ovary lipid concentrations were positively related, and egg size was negatively related to whole-body lipid concentrations; no trends were evident for males. Our results suggest that relationships between walleye reproductive effort and body lipid reserves may be more complex than previously thought.

scholarly journals Nesting Effort of Northern Pintails in Alberta

The Condor ◽  
2000 ◽  
Vol 102 (3) ◽  
pp. 619-628 ◽  
Author(s):  
Karla L. Guyn ◽  
Robert G. Clark
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Reproductive Output ◽  
Reproductive Traits ◽  
Trade Off ◽  
Variable Environments ◽  
Southern Alberta ◽  
First Clutch ◽  
Northern Pintails ◽  
One Year

Abstract We studied nesting effort and success of Northern Pintails (Anas acuta) in southern Alberta. Annual nesting success estimates ranged from 6–18%. Clutch size averaged 7.2, and declined in a simple curvilinear fashion with nest initiation date. We found no relationship between egg size and clutch size or evidence from one year to the next of a trade-off between current and future investment in eggs. Within-year renesting rate ranged from 55%, based on a sample of 20 decoy-trapped females that lost their first nests to predators, to 85% based on a sample of 13 nest-trapped females forced to renest when we removed their clutches. Greater investment in initial clutches led to longer delays in laying replacement clutches. Because delays in renesting are costly (late-nesting females produce fewer offspring), females must contend with a trade-off between maximizing reproductive output in initial clutches versus the risk of delayed renesting if the first clutch should fail. We suggest that pintail reproductive traits have evolved primarily in response to short nesting seasons and variable environments.

Communication Sciences and Disorders PhD Graduates' Perceptions of Their PhD Program

2020 ◽  
Vol 5 (2) ◽  
pp. 463-478
Author(s):  
Elizabeth Crais ◽  
Melody Harrison Savage
Keyword(s):  
Detailed Examination ◽  
Career Expectations ◽  
Doctoral Preparation ◽  
Creative Solutions ◽  
Phd Education ◽  
Doctor Of Philosophy ◽  
First Time ◽  
Students Success ◽  
Phd Program

Purpose The shortage of doctor of philosophy (PhD)–level applicants to fill academic and research positions in communication sciences and disorders (CSD) programs calls for a detailed examination of current CSD PhD educational practices and the generation of creative solutions. The intended purposes of the article are to encourage CSD faculty to examine their own PhD program practices and consider the perspectives of recent CSD PhD graduates in determining the need for possible modifications. Method The article describes the results of a survey of 240 CSD PhD graduates and their perceptions of the challenges and facilitators to completing a PhD degree; the quality of their preparation in research, teaching, and job readiness; and ways to improve PhD education. Results Two primary themes emerged from the data highlighting the need for “matchmaking.” The first time point of needed matchmaking is prior to entry among students, mentors, and expectations as well as between aspects of the program that can lead to students' success and graduation. The second important matchmaking need is between the actual PhD preparation and the realities of the graduates' career expectations, and those placed on graduates by their employers. Conclusions Within both themes, graduate's perspectives and suggestions to help guide future doctoral preparation are highlighted. The graduates' recommendations could be used by CSD PhD program faculty to enhance the quality of their program and the likelihood of student success and completion. Supplemental Material https://doi.org/10.23641/asha.11991480

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