Reproductive performance in a phyletic dwarf, the spider crab Petramithrax pygmaeus (Bell, 1836) (Decapoda: Brachyura: Mithracidae)

2020 ◽  
Vol 40 (3) ◽  
pp. 325-329
Author(s):  
Joshua T Fields ◽  
Hayden K Mullen ◽  
Clayr M Kroenke ◽  
Kyla A Salomon ◽  
Abby J Craft ◽  
...  
Keyword(s):  
Body Size ◽  
Reproductive Performance ◽  
Related Species ◽  
Egg Production ◽  
Marine Invertebrates ◽  
Small Body ◽  
Reproductive Investment ◽  
Spider Crab ◽  
Closely Related Species ◽  
Body Sizes

Abstract The spider crab Petramithrax pygmaeus (Bell, 1836), a phyletic dwarf, was used to test predictions regarding reproductive performance in small marine invertebrates. Considering the disproportional increase in brooding costs and the allometry of egg production with increasing body size, it was expected that this minute-size species would produce large broods compared to closely related species that attain much larger body sizes. Fecundity in P. pygmaeus females carrying early and late eggs varied, respectively, between 17 and 172 eggs crab–1 (mean ± SD = 87.97 ± 48.39) and between 13 and 159 eggs crab–1 (55.04 ± 40.29). Females did not experience brood loss during egg development. Egg volume in females carrying early and late eggs varied, respectively, between 0.13 and 0.40 mm3 (0.22 ± 0.07) and between 0.15 and 0.42 mm3 (0.26 ± 0.06 mm3). Reproductive output (RO) varied between 0.91 and 8.73% (3.81 ± 2.17%) of female dry body weight. The RO of P. pygmaeus was lower than that reported for closely related species with larger body sizes. The slope (b = 0.95 ± 0.15) of the line describing the relationship between brood and parental female dry weight was not statistically significant from unity. Overall, our results disagree with the notion that the allometry of gamete production and increased physiological costs with increased brood size explain the association between brooding and small body size in marine invertebrates. Comparative studies on the reproductive investment of brooding species belonging to monophyletic clades with extensive differences in body size are warranted to further our understanding about disparity in egg production in brooding marine invertebrates.

scholarly journals Will giant polar amphipods be first to fare badly in an oxygen-poor ocean? Testing hypotheses linking oxygen to body size

2019 ◽  
Vol 374 (1778) ◽  
pp. 20190034 ◽  
Author(s):  
John I. Spicer ◽  
Simon A. Morley
Keyword(s):  
Climate Change ◽  
Body Size ◽  
Marine Invertebrates ◽  
Global Climate ◽  
Small Body ◽  
Oxygen Limitation ◽  
Amphipod Species ◽  
Evolutionary Innovation ◽  
Wide Range ◽  
Body Sizes

It has been suggested that giant Antarctic marine invertebrates will be particularly vulnerable to declining O 2 levels as our ocean warms in line with current climate change predictions. Our study provides some support for this oxygen limitation hypothesis, with larger body sizes being generally more sensitive to O 2 reductions than smaller body sizes. However, it also suggests that the overall picture is a little more complex. We tested predictions from three different, but overlapping, O 2 -related hypotheses accounting for gigantism, using four Antarctic amphipod species encompassing a wide range of body sizes. We found a significant effect of body size, but also of species, in their respiratory responses to acutely declining O 2 tensions. The more active lifestyle of intermediate-sized Prostebbingia brevicornis was supported by a better respiratory performance than predicted by the oxygen limitation hypothesis alone, but consistent with the symmorphosis hypothesis. We suggest that giant polar amphipods are likely to be some of the first to fare badly in an O 2 -poor ocean. However, the products of past evolutionary innovation, such as respiratory pigments that enhance O 2 -transport and novel gas exchange structures, may in some species offset any respiratory disadvantages of either large or small body size. This article is part of the theme issue ‘Physiological diversity, biodiversity patterns and global climate change: testing key hypotheses involving temperature and oxygen’.

scholarly journals Assessment of the Growth and Reproductive Performance of Cloned Pietrain Boars

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2053
Author(s):  
Junsong Shi ◽  
Baohua Tan ◽  
Lvhua Luo ◽  
Zicong Li ◽  
Linjun Hong ◽  
...  
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Growth Performance ◽  
Reproductive Performance ◽  
Semen Quality ◽  
Small Body ◽  
Economic Benefits ◽  
Large Animal ◽  
Significant Difference ◽  
F1 Progeny

How to maximize the use of the genetic merits of the high-ranking boars (also called superior ones) is a considerable question in the pig breeding industry, considering the money and time spent on selection. Somatic cell nuclear transfer (SCNT) is one of the potential ways to answer the question, which can be applied to produce clones with genetic resources of superior boar for the production of commercial pigs. For practical application, it is essential to investigate whether the clones and their progeny keep behaving better than the “normal boars”, considering that in vitro culture and transfer manipulation would cause a series of harmful effects to the development of clones. In this study, 59,061 cloned embryos were transferred into 250 recipient sows to produce the clones of superior Pietrain boars. The growth performance of 12 clones and 36 non-clones and the semen quality of 19 clones and 28 non-clones were compared. The reproductive performance of 21 clones and 25 non-clones were also tested. Furthermore, we made a comparison in the growth performance between 466 progeny of the clones and 822 progeny of the non-clones. Our results showed that no significant difference in semen quality and reproductive performance was observed between the clones and the non-clones, although the clones grew slower and exhibited smaller body size than the non-clones. The F1 progeny of the clones showed a greater growth rate than the non-clones. Our results demonstrated through the large animal population showed that SCNT manipulation resulted in a low growth rate and small body size, but the clones could normally produce F1 progeny with excellent growth traits to bring more economic benefits. Therefore, SCNT could be effective in enlarging the merit genetics of the superior boars and increasing the economic benefits in pig reproduction and breeding.

Protamine-like proteins: evidence for a novel chromatin structure

2002 ◽  
Vol 80 (3) ◽  
pp. 353-361 ◽  
Author(s):  
John D Lewis ◽  
Juan Ausió
Keyword(s):  
Protein Expression ◽  
Chromatin Structure ◽  
Related Species ◽  
Marine Invertebrates ◽  
Protein Sequences ◽  
Careful Examination ◽  
Closely Related Species ◽  
Post Translational Modifications ◽  
High Degree ◽  
Degree Of Heterogeneity

Protamine-like (PL) proteins are DNA-condensing proteins that replace somatic-type histones during spermatogenesis. Their composition suggests a function intermediate to that of histones and protamines. Although these proteins have been well characterized at the chemical level in a large number of species, particularly in marine invertebrates, little is known about the specific structures arising from their interaction with DNA. Speculation concerning chromatin structure is complicated by the high degree of heterogeneity in both the number and size of these proteins, which can vary considerably even between closely related species. After careful examination and comparison of the protein sequences available to date for the PL proteins, we propose a model for a novel chromatin structure in the sperm of these organisms that is mediated by somatic-type histones, which are frequently found associated with these proteins. This structure supports the concept that the PL proteins may represent various evolutionary steps between a sperm-specific histone H1 precursor and true protamines. Potential post-translational modifications and the control of PL protein expression and deposition are also discussed.Key words: protamine-like proteins, histones, chromatin structure, sperm, evolution.

Reproductive patterns of European pond turtles differ between sites: a small scale scenario

2015 ◽  
Vol 36 (4) ◽  
pp. 339-349
Author(s):  
Marco A.L. Zuffi ◽  
Elena Foschi
Keyword(s):  
Body Size ◽  
Egg Production ◽  
Shell Height ◽  
The Body ◽  
Small Scale ◽  
Central Mediterranean ◽  
Population Structures ◽  
Body Sizes ◽  
Reproductive Females ◽  
Similar Body

From 1996 to 2002, we studied the body size, measures of reproductive strategy (relative clutch mass and delayed reproduction at sexual maturity), and reproductive output (clutch frequency and annual egg production) of female European Pond turtles,Emys orbicularis, at two sites separated by 12 km in central Mediterranean Tuscany (San Rossore and Camp Darby, central northern Italy). Females did not reproduce at the first appearance of external sexual characters, but reproduced at larger sizes, probably as older turtles. Among years, reproductive females were more common than were non-reproductive females, yet both groups had similar body sizes. Body size (carapace length and width, plastron length and width, shell height and body mass) varied between localities and among years. Body size differed between reproductive and non reproductive females in Camp Darby, but not in San Rossore females. Shell volume did not vary among years, nor between localities, nor between reproductive status. Reproductive females had higher body condition indices (BCI) than did non-reproductive females, while BCI did not differ between females laying one clutch and females laying multiple clutches. Clutch size did not vary among years. One clutch per year was much more frequent than multiple clutches, and multiple clutches were more frequent in Camp Darby than in San Rossore females, likely due to differences in population structures between sites.

scholarly journals Production of common carp donor-derived offspring from goldfish surrogate broodstock

2020 ◽  
Author(s):  
Roman Franěk ◽  
Vojtěch Kašpar ◽  
David Gela ◽  
Martin Pšenička
Keyword(s):  
Stem Cells ◽  
Body Size ◽  
Common Carp ◽  
Germ Cells ◽  
Reproductive Performance ◽  
Small Body ◽  
Important Species ◽  
Testicular Cells

AbstractBackgroundCommon carp is the fourth most-produced species in worldwide aquaculture. Significant efforts are invested in breeding and preservation of genetic integrity of this important species. However, maintaining carp gene bank in situ can be considered as demanding due to its big body size. Recent progress in reproductive biotechnologies in fish allows improving some unfavourable characteristics of a target species using surrogate reproduction. Germ stem cells (gamete precursors) from one species are transplanted into different surrogate species with small body size. After maturation, surrogates are producing donor-derived progeny. Efficient protocols for cryopreservation of carp male and female germ stem cells have been developed lately. Thus, the next logical goal was to assess the potential of goldfish surrogate to produce donor-derived gametes of common carp after intraperitoneal transplantation of testicular cells.ResultsHigh transplantation success was achieved when 44% of the surviving goldfish produced pure donor-derived gametes of common carp. More importantly, both viable eggs and sperm giving rise to pure common carp progeny were produced, witnessing sustainability of the presented method. Donor-derived identity of the offspring was confirmed by genotyping and typical phenotype corresponding to the donor species. Reproductive performance of chimeras was similar to goldfish controls. Assessment of gamete characteristics showed that the size of donor-derived eggs is between control carp and goldfish eggs. Interestingly, flagellum length in donor-derived spermatozoa was comparable to common carp flagellum and significantly shorter than goldfish flagellum.ConclusionsIn this study, we succeeded in the production of pure common carp progeny from surrogate goldfish recipients transplanted intraperitoneally by testicular germ cells. Here we reported production of viable eggs between most distant species up to date. Good reproductive performance of goldfish germline chimeras gives a promising prospect for further analysis about the long-term reproductive performance of surrogates, recovery of cryopreserved germ cells or production of monosex stocks. Presented technology is ready to ease needs for carp breeds preservation and their recovery using many times smaller goldfish surrogates.

scholarly journals Functional diversity of small-mammal postcrania is linked to both substrate preference and body size

2020 ◽  
Vol 66 (5) ◽  
pp. 539-553
Author(s):  
Lucas N Weaver ◽  
David M Grossnickle
Keyword(s):  
Body Size ◽  
Phenotypic Diversity ◽  
Small Body ◽  
Ecological Factors ◽  
Morphological Divergence ◽  
Functional Diversification ◽  
Evolutionary Patterns ◽  
Selective Pressures ◽  
Trade Offs ◽  
Body Sizes

Abstract Selective pressures favor morphologies that are adapted to distinct ecologies, resulting in trait partitioning among ecomorphotypes. However, the effects of these selective pressures vary across taxa, especially because morphology is also influenced by factors such as phylogeny, body size, and functional trade-offs. In this study, we examine how these factors impact functional diversification in mammals. It has been proposed that trait partitioning among mammalian ecomorphotypes is less pronounced at small body sizes due to biomechanical, energetic, and environmental factors that favor a “generalist” body plan, whereas larger taxa exhibit more substantial functional adaptations. We title this the Divergence Hypothesis (DH) because it predicts greater morphological divergence among ecomorphotypes at larger body sizes. We test DH by using phylogenetic comparative methods to examine the postcranial skeletons of 129 species of taxonomically diverse, small-to-medium-sized (<15 kg) mammals, which we categorize as either “tree-dwellers” or “ground-dwellers.” In some analyses, the morphologies of ground-dwellers and tree-dwellers suggest greater between-group differentiation at larger sizes, providing some evidence for DH. However, this trend is neither particularly strong nor supported by all analyses. Instead, a more pronounced pattern emerges that is distinct from the predictions of DH: within-group phenotypic disparity increases with body size in both ground-dwellers and tree-dwellers, driven by morphological outliers among “medium”-sized mammals. Thus, evolutionary increases in body size are more closely linked to increases in within-locomotor-group disparity than to increases in between-group disparity. We discuss biomechanical and ecological factors that may drive these evolutionary patterns, and we emphasize the significant evolutionary influences of ecology and body size on phenotypic diversity.

Similar nucleus numbers among copepods

1983 ◽  
Vol 61 (4) ◽  
pp. 721-724 ◽  
Author(s):  
I. A. McLaren ◽  
D. J. Marcogliese
Keyword(s):  
Body Size ◽  
Related Species ◽  
Calanus Finmarchicus ◽  
Close Correspondence ◽  
Nucleus Size ◽  
Closely Related Species ◽  
Acartia Hudsonica ◽  
Eurytemora Herdmani

First nauplius stages (NI) of Pseudocalanus sp., Eurytemora herdmani, Calanus finmarchicus, and C. hyperboreas all have on average about 2000 nuclei. First copepodid stages (CI) of Acartia hudsonica, Pseudocalanus sp., E. herdmani, C. finmarchicus and C. glacialis have about 9600–13 000 nuclei. Body volumes among the same species differ ca. 8-fold in NI and 30-fold in CI. Larger species have much larger nuclei, but close correspondence of body size to nucleus size (amount of DNA) may only occur among closely related species. Nucleocytoplasmic ratios must also vary seasonally within species.

Body Size, Adaptation and Function

1989 ◽  
Vol 48 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Reynaldo Martorell
Keyword(s):  
Developing Countries ◽  
Body Size ◽  
Cognitive Development ◽  
Growth Retardation ◽  
Small Body ◽  
Warning Signal ◽  
Increased Risk ◽  
Body Sizes ◽  
And Function ◽  
Excellent Tool

This is a brief discussion of the "small but healthy" hypothesis proposed by David Seckler in the early 1980s. Four basic points are made. First, adults in developing countries have small body sizes largely as a result of poor diets and infection during childhood. Therefore, to acclaim small body sizes as a desirable attribute for populations is also to affirm that its causes are desirable. Second, monitoring the growth of children is widely recognized as an excellent tool for detecting health problems. Growth retardation, rather than an innocuous response to environmental stimuli, is a warning signal of increased risk of morbidity and mortality. Third, the conditions which give rise to stunted children also affect other aspects such as cognitive development. Finally, stunted girls who survive to be short women are at greater risk of delivering growth retarded infants with a greater probability of dying in infancy. For all these reasons, small is not healthy.

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