scholarly journals Specialization for Tachinid Fly Pollination in the Phenologically Divergent Varieties of the Orchid Neotinea ustulata

2021 ◽  
Vol 9 ◽  
Author(s):  
Carlos Martel ◽  
Demetra Rakosy ◽  
Stefan Dötterl ◽  
Steven D. Johnson ◽  
Manfred Ayasse ◽  
...  
Keyword(s):  
Reproductive Biology ◽  
Reproductive Strategy ◽  
Reproductive Strategies ◽  
Floral Traits ◽  
Deceptive Pollination ◽  
Fly Pollination ◽  
Pollination Systems

Despite increased focus on elucidating the various reproductive strategies employed by orchids, we still have only a rather limited understanding of deceptive pollination systems that are not bee- or wasp-mediated. In Europe, the orchid Neotinea ustulata has been known to consist of two phenologically divergent varieties, neither of which provide rewards to its pollinators. However, detailed studies of their reproductive biology have been lacking. Our study aimed to characterize and understand the floral traits (i.e., morphology, color, and scent chemistry) and reproductive biology of N. ustulata. We found that the two varieties differ in all their floral traits; furthermore, while Neotinea ustulata var. ustulata appears to be pollinated by both bees (e.g., Anthophora, Bombus) and flies (e.g., Dilophus, Tachina), var. aestivalis is pollinated almost entirely by flies (i.e., Nowickia, Tachina). Tachinids were also found to be much more effective than bees in removing pollinaria, and we show experimentally that they use the characteristic dark inflorescence top as a cue for approaching inflorescences. Our results thus suggest that while both N. ustulata varieties rely on tachinids for pollination, they differ in their degree of specialization. Further studies are, however, needed to fully understand the reproductive strategy of N. ustulata varieties.

scholarly journals Uterine fluid composition of the dwarf ornate wobbegong shark (Orectolobus ornatus) during gestation

2011 ◽  
Vol 62 (6) ◽  
pp. 576 ◽  
Author(s):  
Megan T. Ellis ◽  
Nicholas M. Otway
Keyword(s):  
Reproductive Biology ◽  
Coastal Waters ◽  
Reproductive Strategies ◽  
Yolk Sac ◽  
Gestation Period ◽  
Fluid Composition ◽  
Complex Composition ◽  
Eastern Australia ◽  
Uterine Fluid ◽  
Low Levels

Low fecundity in chondrichthyans makes them extremely susceptible to fishing, so understanding the various reproductive strategies in this group is vital for management. Knowledge of the uterine fluid (UF) composition throughout gestation is fundamental to this understanding, yet is restricted to a few species. This study focussed on the UF composition of the wobbegong (Orectolobus ornatus), which inhabits coastal waters off eastern Australia. The UF was quantified throughout pregnancy. Fluids surrounding uterine eggs had a complex composition, with mean urea (98.48 mmol L–1), sodium (560.25 mmol L–1) and potassium (13.93 mmol L–1) concentrations significantly greater than those in seawater. A change in composition, from complex to simple, occurred after 3–4 months gestation. Major electrolyte concentrations then resembled seawater for the remainder of gestation, suggesting the flushing of the uteri with seawater and evidenced by fluctuating low levels of urea. The gestation period reflected the time for metabolism of yolk stores, osmotic and ionic adjustment, development of functioning immunological systems and prevention of external yolk sac damage. Our study is the first documentation of UF composition for a wobbegong shark and increases understanding of its reproductive biology.

scholarly journals Pollination Efficiency and the Evolution of Specialized Deceptive Pollination Systems

2010 ◽  
Vol 175 (1) ◽  
pp. 98-105 ◽  
Author(s):  
Giovanni Scopece ◽  
Salvatore Cozzolino ◽  
Steven D. Johnson ◽  
Florian P. Schiestl
Keyword(s):  
Pollination Efficiency ◽  
Deceptive Pollination ◽  
Pollination Systems

The reproductive biology of Plutonaster Bifrons, Dytaster Insigns and Psilaster Andromeda (Asteroidea: Astropectinidae) from the Rockall Trough

1982 ◽  
Vol 62 (4) ◽  
pp. 869-887
Author(s):  
P. A. Tyler ◽  
S. L. Pain
Keyword(s):  
Reproductive Biology ◽  
Reproductive Strategies ◽  
Egg Size ◽  
Food Source ◽  
Maximum Size ◽  
Reproductive Synchrony ◽  
Sea Bed ◽  
Rockall Trough ◽  
Sperm Development ◽  
Surface Production

Examination of the reproductive biology of three closely related sympatric astropectinid asteroidshas revealed two distinct reproductive strategies. In Plutonaster bifrons and Dytaster insignis the gonads are serially arranged and open at gonopores located at the tip of genital papillae found on the dorsal arm surface between the bases of the paxillae. The ovaries of these species produce numerous small (ca. 120/«n diameter) eggs which in Plutonaster bifrons appear to show a distinct synchrony of production. Initiation of gametogenesis occurs in June to August of each year with oocyte growthcontinuing until March with a spawn-out in the period March to early June. In specimens where spawningdoesnot occur, there would appear to be internal oocyte degeneration, or after spawning relict oocytesundergo phagocytosis. In males initiation of spermatogenesis may occur in August/September of eachyear but after this synchrony of sperm development is not evident. In Psilaster andromeda gonads are located at the base of the arms and each gonad opens at a single gonopore. A number of small (<300 /«n) oocytes are produced by each gonad. Some of these are phagocytosed and some undergo vitellogenesis and grow to a maximum size of 950 fim before being spawned. Unspent oocytes undergo internal degeneration. In neither females nor males is there any evidence of reproductive synchrony. From these egg sizes, fecundities and gametogenic strategies, we infer indirect planktotrophic development for Plutonaster bifrons, the transfer of a seasonal surface production to deep water providing a food source for developing larvae. The egg size and or close to the sea-bed, as there is no evidence of brooding in this species.

Atypical reproduction in a syllid worm: the stolon of Syllis rosea (Annelida, Syllidae) takes care of its offspring

2020 ◽  
Vol 100 (2) ◽  
pp. 221-227
Author(s):  
Joachim Langeneck ◽  
Michela Del Pasqua ◽  
Margherita Licciano ◽  
Adriana Giangrande ◽  
Luigi Musco
Keyword(s):  
Parental Care ◽  
Sexual Reproduction ◽  
Reproductive Strategy ◽  
Reproductive Strategies ◽  
Congeneric Species ◽  
Reproduction Mode ◽  
Laboratory Rearing ◽  
Larval Stages ◽  
The Family ◽  
Reproductive Cycles

AbstractThe family Syllidae, aside from representing the most species-rich family in Annelida, is characterized by a number of sexual and asexual reproductive strategies. With the exception of a few viviparous species, the subfamily Syllinae is characterized by schizogamous reproduction with pelagic larval stages and without parental care. Laboratory rearing of ripe specimens of Syllis rosea showed a different reproductive strategy, hitherto unknown in this subfamily. While male stolons rapidly degenerated after fertilization, female ones released large eggs in a gelatinous cluster attached to the middle-posterior chaetigers. The gel mass progressively compacted as a cocoon wrapped by the stolon body; 7 days after the deposition the larvae hatched out from the cocoon at the metatrochophore stage and the female stolon died after a few days. After hatching the larvae remained associated to the stolon, and young specimens of S. rosea survived up to the 3-chaetiger stage. Until now cocoon brooding by the stolon has only been reported for some Autolytinae. The production of gelatinous egg masses and parental care are known in basally branching clades within Syllidae, suggesting that this reproduction mode might retain some ancestral features. The scarce knowledge about reproductive cycles in Syllinae does not allow clarification whether this strategy is unique for S. rosea, or it occurs in other congeneric species. Further research is needed to understand possible relationships between sexual reproduction and phylogeny, stolon morphology and its adaptation to parental care, and ultimately between reproductive strategies and ecology.

Are diel patterns of nectar production and anthesis associated with other floral traits in plants visited by potential bird and mammal pollinators?

2004 ◽  
Vol 52 (1) ◽  
pp. 87 ◽  
Author(s):  
V. M. Saffer
Keyword(s):  
Western Australia ◽  
Visual Cues ◽  
Floral Traits ◽  
Pollination Syndromes ◽  
Nectar Production ◽  
Diel Patterns ◽  
Pollen Presentation ◽  
Pollination Systems

Plants pollinated predominantly by vertebrates are thought to have suites of floral traits (e.g.�colour, conspicuousness, odour) that favour either birds or mammals, with brightly coloured, conspicuous flowers associated with birds and drab, concealed flowers with non-flying mammals. This study examined two other floral traits, diel patterns of nectar production and pollen presentation (anthesis). It would be expected that these would be nocturnal in putatively mammal-pollinated plants and diurnal in bird-pollinated plants. In four Banksia and two Dryandra species, all known to be visited by honeyeater birds and small marsupials at one site in south-western Australia, there was no clear correspondence between visual cues and diel patterns of resource presentation. This lack of correlation between floral traits does not support the idea of specialised pollination syndromes, but rather is consistent with generalised pollination systems.

Twinning and the r/K Reproductive Strategy: A Critique of Rushton's Theory

1992 ◽  
Vol 41 (1) ◽  
pp. 73-83 ◽  
Author(s):  
G. Allen ◽  
A.W. Eriksson ◽  
J. Fellman ◽  
P. Parisi ◽  
S.G. Vandenberg
Keyword(s):  
Environmental Factors ◽  
Population Growth ◽  
Parental Care ◽  
Ethnic Groups ◽  
Ethnic Differences ◽  
Reproductive Strategy ◽  
Reproductive Strategies ◽  
Human Populations ◽  
Efficient Utilization ◽  
Mode Of Reproduction

AbstractThe theory of r selection, favoring population growth, as opposed to K selection, favoring more efficient utilization of resources, has in recent years been applied by Rushton to contrast human ethnic groups in terms of their r/K reproductive strategies, suggesting the existence of a continuum from r groups, producing many offspring but providing little parental care, to K groups, producing few offspring but providing much parental care. Rushton's theory, which is largely based on ethnic differences in twinning rates, is here critically examined. It is pointed out that twinning rate differences are not necessarily genetic in origin since various environmental factors clearly play a role, and also that twinning, as a mode of reproduction, is not necessarily an r strategy, considering the high prenatal and perinatal selection to which it has been, and still is, associated. Moreover, Rushton misinterprets a number of relevant aspects related to the biology of twinning. The claim that ethnic differences in twinning rates provide evidence for an r/K typology in human populations with respect to reproductive strategies does not appear to be warranted.

Reproductive strategies in hermaphroditic gastropods: conceptual and empirical approaches

2013 ◽  
Vol 91 (6) ◽  
pp. 367-381 ◽  
Author(s):  
Yumi Nakadera ◽  
Joris M. Koene
Keyword(s):  
Sexual Selection ◽  
Reproductive Success ◽  
Experimental Research ◽  
Reproductive System ◽  
Reproductive Strategy ◽  
Reproductive Strategies ◽  
Sex Allocation ◽  
Fitness Consequences ◽  
The Individual ◽  
Empirical Approaches

An individual optimizes its reproductive success by adopting a particular reproductive strategy. Studying the details of a reproductive strategy leads to an understanding of how sexual selection acts, as the former is the process via which the individual reproduces successfully. Hermaphroditic gastropods display a bewildering diversity of reproductive strategies, which may be due to their mode of gender expression, when compared with well-studied separate-sexed species. Extensive theoretical, observational, and experimental research has been conducted on this topic. However, despite our knowledge about the reproductive system of hermaphroditic gastropods, we still need to fill the gap between pre- and post-copulatory processes and reproductive success. Here, we review and propose conceptual and empirical approaches aimed at understanding reproductive strategies of hermaphroditic gastropods. In sum, our suggestions are (i) to focus on sex-biased traits, (ii) to take biologically reliable measurements at both the pre- and post-copulatory level that relate to reproductive success, and (iii) to examine the fitness consequences of biased sex allocation.

scholarly journals Reproductive Biology in Northern Prickly Ash

2018 ◽  
Vol 143 (1) ◽  
pp. 72-83
Author(s):  
David A. Munter ◽  
James J. Luby ◽  
Neil O. Anderson
Keyword(s):  
Reproductive Biology ◽  
Reproductive Strategies ◽  
Economic Importance ◽  
Reproductive Barriers ◽  
Pollen Stainability ◽  
Dioecious Species ◽  
Zanthoxylum Americanum ◽  
The Mean ◽  
Northern Forests ◽  
Autonomous Apomixis

Zanthoxylum americanum is a common understory species in the northern forests of Minnesota and surrounding regions. It has potential economic importance for its citrus fragrance, pharmacological or insecticidal properties, and produces peppercorns similar to those of the related Zanthoxylum species. Zanthoxylum americanum is a dioecious species but has been reported to have aberrant flowers with autonomous apomixis instead of other potential reproductive barriers. The reproductive biology of Zanthoxylum americanum was investigated in two native Minnesota populations. Determinations of male fertility, whether autonomous apomixis was the predominant floral reproductive mechanism, the presence of seedless fruit (parthenocarpy/stenospermocarpy), and the occurrence of hermaphrodism were made over 2 years. Sex ratios (female:male plants) within each population differed. The mean pollen stainability was 95.8% ± 0.3% (fresh) and 78.6% ± 1.1% (stored 18 months). Parthenocarpy did not occur in either population. Autonomous apomixis was not the primary floral reproductive mechanism. Stenospermocarpy (seedlessness) occurred in 13% of the female fruit clusters. Although commonly described as being dioecious, two additional reproductive strategies were identified: 1) plants with functional protandrous flowers with rudimentary pistils and 2) hermaphroditic flowers with fully functional pistils (protogynous) and anthers. As many as 10% to 30% of the male plants bore at least one fruit/plant each year. One clonal stand had both hermaphroditic and functionally staminate flowers on the same plant. Two evolutionary pathways to dioecy in Z. americanum are proposed.

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