scholarly journals Reproduction, development, asymmetry and late eye regression in the Brazilian cave catfish Ituglanis passensis (Siluriformes, Trichomycteridae): evidence contributing to the neutral mutation theory

2021 ◽  
Vol 38 ◽  
pp. 91-112
Author(s):  
Sandro Secutti ◽  
Eleonora Trajano
Keyword(s):  
Egg Size ◽  
Egg Laying ◽  
Karst Area ◽  
Source Population ◽  
Central Brazil ◽  
Neutral Mutation ◽  
Mutation Theory ◽  
Neutral Mutation Theory ◽  
One Year ◽  
Cave Habitat

The troglobitic (exclusively subterranean source population) catfish Ituglanis passensis (Siluriformes, Trichomycteridae) is endemic to the Passa Três Cave, São Domingos karst area, Rio Tocantins basin, Central Brazil. This unique population presents variably reduced eyes and melanic pigmentation. We describe reproduction and early development in this species based on a spontaneous (non-induced) reproductive-event that occurred in the laboratory in January–February, 2009, while simultaneously comparing with data from the cave-habitat and a previous reproductive event. Egg laying was parceled. Egg-size and number were within variations observed in epigean congeners. Larvae behavior and growth is described. A single surviving specimen was monitored over two years. Eye-regression started late, one year after birth, and followed a pattern of stasis phases intercalated with slow growth and fluctuating asymmetric rates. Late eye regression, associated with asymmetry in eye development and intra-population variability of troglomorphic traits, as shown by several Brazilian subterranean fishes, provide support for the Neutral Mutation Theory.

On the genealogy of large populations

1982 ◽  
Vol 19 (A) ◽  
pp. 27-43 ◽  
Author(s):  
J. F. C. Kingman
Keyword(s):  
Markov Chain ◽  
Family Relationships ◽  
Neutral Mutation ◽  
Mutation Theory ◽  
The Family ◽  
Large Populations ◽  
Coupling Techniques ◽  
Neutral Mutation Theory ◽  
Haploid Population

A new Markov chain is introduced which can be used to describe the family relationships among n individuals drawn from a particular generation of a large haploid population. The properties of this process can be studied, simultaneously for all n, by coupling techniques. Recent results in neutral mutation theory are seen as consequences of the genealogy described by the chain.

On the genealogy of large populations

1982 ◽  
Vol 19 (A) ◽  
pp. 27-43 ◽  
Author(s):  
J. F. C. Kingman
Keyword(s):  
Markov Chain ◽  
Family Relationships ◽  
Neutral Mutation ◽  
Mutation Theory ◽  
The Family ◽  
Large Populations ◽  
Coupling Techniques ◽  
Neutral Mutation Theory ◽  
Haploid Population

A new Markov chain is introduced which can be used to describe the family relationships among n individuals drawn from a particular generation of a large haploid population. The properties of this process can be studied, simultaneously for all n, by coupling techniques. Recent results in neutral mutation theory are seen as consequences of the genealogy described by the chain.

Clutch Initiation Dates, Clutch Size, and Egg Size of the American Oystercatcher in Virginia

The Auk ◽  
1984 ◽  
Vol 101 (4) ◽  
pp. 855-867 ◽  
Author(s):  
Erica Nol ◽  
Allan J. Baker ◽  
Michael D. Cadman
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Egg Laying ◽  
American Oystercatcher ◽  
Mode 2 ◽  
Haematopus Palliatus ◽  
Clutch Initiation ◽  
Mode 3 ◽  
One Year ◽  
Breeding Seasons

AbstractThe timing of egg laying, clutch size, and egg size of the American Oystercatcher (Haematopus palliatus) were studied over six consecutive breeding seasons in Virginia. Synchrony of laying dates occurred in each of five localities of the study area in at least one year. Mean clutch size was 2.8 eggs (mode = 3) in first clutches and 2.4 eggs (mode = 2) in replacement clutches. Individual females laid replacement clutches of the same size and laid eggs of similar average volume in all years. A change in mate had little effect on the date on which females initiated their first clutches in successive years. The average egg size in a clutch was correlated with the size of the laying female. Egg-size ordering occurred within clutches, the first-laid egg being smaller than the second egg and about equal in volume to the third. We propose that the second egg is largest because it has the highest probability of hatching, and the resulting sibling hierarchy reduces the frequency of sibling competition.

scholarly journals Population size and protein variation in man

1972 ◽  
Vol 19 (1) ◽  
pp. 73-89 ◽  
Author(s):  
John Haigh ◽  
John Maynard Smith
Keyword(s):  
Population Size ◽  
Effective Population ◽  
Human Species ◽  
Neutral Mutation ◽  
Mutation Theory ◽  
Neutral Mutation Theory ◽  
Pattern Of Variation ◽  
Using Data ◽  
Image Position ◽  
Neutral Mutation Rate

SUMMARYThe ‘neutral mutation theory’ holds that most amino acid substitutions in evolution are selectively neutral. The known pattern of variation in human haemoglobins can only be made consistent with this theory if the human species has passed through a bottleneck of numbers in the recent past. If this theory is true, estimates of the necessary size and duration of this bottleneck can be made. A theory is developed which leads to an estimate of Yg, n, the number of alleles present in a population which arise between g and n generations ago, and hence to the estimatewhere u is the neutral mutation rate and Ne the effective population size, for the probability that a population contains no such alleles. Using data on haemoglobins, this gives an approximate upper limit to the time elapsed since the bottleneck in human numbers. Either such a bottleneck occurred, or the neutral mutation theory is false; data on other proteins will enable a choice between these possibilities to be made.

Oviparous reproduction of Vestia ranojevici moravica confirms taxonomic value of life history characters in carpathian clausiliids (Gastropoda: Pulmonata)

Biologia ◽  
2013 ◽  
Vol 68 (4) ◽  
Author(s):  
Anna Sulikowska-Drozd ◽  
Tomasz Maltz
Keyword(s):  
Reproductive Strategies ◽  
Egg Size ◽  
Room Temperature ◽  
Reproductive Tract ◽  
Shell Growth ◽  
Egg Laying ◽  
Anatomical Studies ◽  
One Year ◽  
Previous Assumption ◽  
Actual Size

AbstractBased on five-year observation of 36 snails collected in the Čeladná valley (Moravia, Czech Republic) and their progeny reared in laboratory, it was found that Vestia ranojevici moravica (Brabenec, 1952) is oviparous. The oviparity in V. ranojevici is in line with the previous assumption of its reproductive strategy based on anatomical studies alone. It supports the separate position of the species in the genus Vestiaa (subgenus Brabenecia). V. ranojevici was kept at room temperature (18–25°C) between March and October; in winter snails were stored at 3°C. The egg-laying period started in late March, ca. 1 month after raising the temperature, and lasted till September, with one maximum in spring. In the laboratory the snails laid eggs in batches (usually 4–6 eggs, max 11) or singly. The number of batches per pair per season was 1–8; the corresponding number of eggs — 3–40. The eggs were gelatinous, with separate calcium carbonate crystals in the external envelope. The average egg size was 1.80 × 1.51 mm, but actual size and shape were highly variable: larger and more elongated eggs were produced mainly by laboratory reared animals. Freshly deposited eggs did not contain shelled embryos nor the reproductive tract of dissected individuals contained eggs. At room temperature the eggs hatched after ca. 14–16 days, then the shell growth lasted 20–29 weeks; the snails laid eggs 30 weeks after completion of shell growth indicating one-year life cycle under laboratory conditions. Adult individuals collected in the field reproduced during 4–5 consecutive years. Comparison of V. ranojevici reproduction to the results of breeding of other Carpathian clausiliids in the same laboratory shows that similar reproductive strategies may have evolved independently in different lineages of the group: both the oviparous and egg retaining species belong to the genera Vestia and Balea.

Breeding biology of the Critically Endangered Tahiti MonarchPomarea nigra, a bird with a low productivity

2017 ◽  
Vol 28 (4) ◽  
pp. 606-619 ◽  
Author(s):  
CAROLINE BLANVILLAIN ◽  
THOMAS GHESTEMME ◽  
TEHANI WITHERS ◽  
MARK O’BRIEN
Keyword(s):  
Reproductive Success ◽  
French Polynesia ◽  
Egg Laying ◽  
Breeding Biology ◽  
Critically Endangered ◽  
Tropical Island ◽  
Island Endemics ◽  
Nest Activity ◽  
Considerable Length ◽  
One Year

SummaryWe studied the breeding biology of Tahiti MonarchPomarea nigra, a ‘Critically Endangered’ forest bird endemic to Tahiti (French Polynesia). Nest activity was monitored from 1998 to 2002, and again from 2008 to 2015. During these 12 years, only 2–13 breeding pairs per year produced hatchlings. Egg-laying occurred all year, but usually increased between August and January, peaking around November. Of the 200 nests monitored, 33 (16%) were abandoned shortly after construction, 71 had an egg laid immediately after the nest were completed (34 %) and 96 nests (46 %) had a pre-incubation phase of 18.9 ± 1.9 days (3–62 days;n= 47 nests), during which the birds visited the nest on an irregular basis. Half (49 of 96) of these nests were abandoned before an egg was laid, with incubation subsequently commencing at the remaining nests (n= 47). Although both sexes incubated for an average of 13.6 ± 0.3 days (range 13–15), the female usually spent more time incubating than the male. Only one young per nest was ever observed. The average nestling phase was 15.5 ± 0.7 days (range 13 to 20 days). Parents continue to feed the young after fledging for 74 ± 4.7 days (range 42–174). As with many tropical island endemics, the Tahiti Monarch has low reproductive productivity as indicated by the fact that: 1) only 56% of pairs attempt to lay an egg in any one year, 2) most pairs attempt only one brood per year and 3) the considerable length of the nesting and fledging phases. Because of its low productivity, maximising the reproductive success of the Tahiti Monarch is essential to secure its recovery.

scholarly journals Differentiating cave Aspidoras catfish from a karst area of Central Brazil, upper rio Tocantins basin (Siluriformes: Callichthyidae)

2011 ◽  
Vol 9 (4) ◽  
pp. 689-695 ◽  
Author(s):  
Sandro Secutti ◽  
Roberto E Reis ◽  
Eleonora Trajano
Keyword(s):  
Distinct Species ◽  
Karst Area ◽  
Central Brazil ◽  
The City

Two cave populations of Aspidoras albater catfish with reduced eyes and pigmentation were recently found near the city of Posse, São Domingos karst area, Goiás State, representing the first known case of a troglomorphic callichthyid catfish. Cave specimens are described and compared to epigean specimens of A. albater, but morphometric differences between the epigean and the cave populations are not adequate to delimit as distinct species.

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