Speciation of cestoda. Evidence for two sibling species in the complex Bothrimonus nylandicus (Schneider 1902) (Cestoda: Cyathocephalidea)

Parasitology ◽  
1988 ◽  
Vol 97 (1) ◽  
pp. 139-147 ◽  
Author(s):  
F. Renaud ◽  
C. Gabrion
Keyword(s):  
Sibling Species ◽  
Definitive Host ◽  
Parasite Species ◽  
Adult Stage ◽  
Life Cycles ◽  
The Other ◽  
Congeneric Species ◽  
Biochemical Genetic ◽  
Autumn And Winter ◽  
Biological Differences

SUMMARYUsing biochemical genetic methods, we have distinguished 2 sibling species in the complex Bothrimonus nylandicus (Schneider, 1902), which infest 2 congeneric species of sole (Solea lascaris and Solea impar) on European coasts (Atlantic and Mediterranean). Neither of the parasite species is specific for either of the sole species, but one of them is present all year round, whereas the other is absent in the autumn and winter and only appears in the spring, subsequently disappearing at the end of the summer. Only S. impar lives in the Mediterranean, and is equally infested by both cestodes, whereas both species occur in the Atlantic and each of them is preferentially infested by 1 species of cestode. The shortness of the adult stage of the parasite in the definitive host and the presence of 2 life-cycles associated with competition between the 2 hosts in the Atlantic could be responsible for the biological differences observed and for maintaining the sibling species in sympatry.

Speciation of echinostomes: evidence for the existence of two sympatric sibling species in the complex Echinoparyphium recurvatum (von Linstow 1873) (Digenea: Echinostomatidae)

Parasitology ◽  
1990 ◽  
Vol 101 (1) ◽  
pp. 35-42 ◽  
Author(s):  
A. M. McCarthy
Keyword(s):  
Small Intestine ◽  
Intermediate Host ◽  
Sibling Species ◽  
Definitive Host ◽  
Experimental Studies ◽  
Life Cycles ◽  
The Other ◽  
Excessive Competition ◽  
First Intermediate Host ◽  
Prosobranch Snail

SUMMARYEvidence for the existence of 2 first intermediate host-specific sibling species of the 45 collar-spined echinostome Echinoparyphium recurvatum is presented. Experimental studies on their life-cycles were carried out under controlled laboratory conditions. The two entities were found to be morphologically indistinguishable in all major respects, yet they exhibited distinct biological characteristics. One of the sibling species utilizes the freshwater lymnaeid pulmonate snail Lymnaea peregra as first intermediate host, and the adults occur in the anterior small intestine of the wildfowl experimental definitive host Anas platyrhynchos. The other utilizes the freshwater mesogastropod prosobranch snail Valvata piscinalis as first intermediate host, and the adults occur in the posterior small intestine and rectum of A. platyrhynchos. The existence of the two sibling species in sympatry may be explained by the fact that the life-cycles of the two forms represent two distinct cycles of transmission serving to reduce excessive competition between them.

State of Fashion: Searching for the New Luxury

APRIA Journal ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 11-16
Author(s):  
José Teunissen
Keyword(s):  
Twentieth Century ◽  
Daily Life ◽  
Life Cycles ◽  
The Other ◽  
Century Model ◽  
Cocktail Party ◽  
The Public ◽  
Other Hand ◽  
The One

In the last few years, it has often been said that the current fashion system is outdated, still operating by a twentieth-century model that celebrates the individualism of the 'star designer'. In I- D, Sarah Mower recently stated that for the last twenty years, fashion has been at a cocktail party and has completely lost any connection with the public and daily life. On the one hand, designers and big brands experience the enormous pressure to produce new collections at an ever higher pace, leaving less room for reflection, contemplation, and innovation. On the other hand, there is the continuous race to produce at even lower costs and implement more rapid life cycles, resulting in disastrous consequences for society and the environment.

scholarly journals Limitation of current probe design for oligo-cross-FISH, exemplified by chromosome evolution studies in duckweeds

Chromosoma ◽  
2021 ◽  
Vol 130 (1) ◽  
pp. 15-25
Author(s):  
Phuong T. N. Hoang ◽  
Jean-Marie Rouillard ◽  
Jiří Macas ◽  
Ivona Kubalová ◽  
Veit Schubert ◽  
...  
Keyword(s):  
Growth Rate ◽  
Chromosome Number ◽  
Chromosome Evolution ◽  
Sequence Similarity ◽  
Flowering Plants ◽  
The Other ◽  
Probe Design ◽  
Congeneric Species ◽  
Specific Design ◽  
Spirodela Polyrhiza

AbstractDuckweeds represent a small, free-floating aquatic family (Lemnaceae) of the monocot order Alismatales with the fastest growth rate among flowering plants. They comprise five genera (Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia) varying in genome size and chromosome number. Spirodela polyrhiza had the first sequenced duckweed genome. Cytogenetic maps are available for both species of the genus Spirodela (S. polyrhiza and S. intermedia). However, elucidation of chromosome homeology and evolutionary chromosome rearrangements by cross-FISH using Spirodela BAC probes to species of other duckweed genera has not been successful so far. We investigated the potential of chromosome-specific oligo-FISH probes to address these topics. We designed oligo-FISH probes specific for one S. intermedia and one S. polyrhiza chromosome (Fig. 1a). Our results show that these oligo-probes cross-hybridize with the homeologous regions of the other congeneric species, but are not suitable to uncover chromosomal homeology across duckweeds genera. This is most likely due to too low sequence similarity between the investigated genera and/or too low probe density on the target genomes. Finally, we suggest genus-specific design of oligo-probes to elucidate chromosome evolution across duckweed genera.

XXVII.—The Inheritance of Long and Short Wings in the Weevil, Sitona hispidula, with a Discussion of Wing Reduction among Beetles

1928 ◽  
Vol 55 (3) ◽  
pp. 665-735 ◽  
Author(s):  
Dorothy J. Jackson
Keyword(s):  
Experimental Work ◽  
Adult Stage ◽  
Point Of View ◽  
The Other ◽  
Wing Dimorphism ◽  
Wing Reduction ◽  
Hereditary Factors ◽  
The Subject ◽  
The One ◽  
Evolutionary Point

It is well known that in many orders of typically winged insects species occur which in the adult stage are apterous or have the wings so reduced in size that flight is impossible. Sometimes the reduction of wings affects one sex only, as in the case of the females of certain moths, but in the majority of cases it is exhibited by both sexes. In many instances wing dimorphism occurs irrespective of sex, one form of the species having fully developed wings and the other greatly reduced wings. In some species the wings are polymorphic. The problem of the origin of reduced wings and of other functionless organs is one of great interest from the evolutionary point of view. Various theories have been advanced in explanation, but in the majority of cases the various aspects of the subject are too little known to warrant discussion. More experimental work is required to show how far environmental conditions on the one hand, and hereditary factors on the other, are responsible for this phenomenon. Those species which exhibit alary dimorphism afford material for the study of the inheritance of the two types of wings, but only in a few cases has this method of research been utilized.

Two new inbred rat strains derived from SHR: WKHA, hyperactive, and WKHT, hypertensive, rats

1991 ◽  
Vol 261 (2) ◽  
pp. H583-H589 ◽  
Author(s):  
E. D. Hendley ◽  
W. G. Ohlsson
Keyword(s):  
The Other ◽  
Hypertensive Rats ◽  
Rat Strains ◽  
Spontaneously Hypertensive ◽  
Behavioral Profile ◽  
Behavioral Abnormalities ◽  
Inbred Rats ◽  
Wistar Kyoto ◽  
Inbred Rat ◽  
Biological Differences

Two new strains of inbred rats have been developed. One, WKHA, exhibits hyperactivity, and the other, WKHT, exhibits hypertension. Both of these traits are expressed in the SHR. By crossing spontaneously hypertensive rats (SHRs) with Wistar-Kyoto (WKY) controls, followed by recombinant selected inbreeding, we succeeded in genetically separating the hyperactivity from the hypertension in two new strains. Longitudinal studies indicate a persistence of hypertension without hyperactivity in WKHTs, and hyperactivity without hypertension in WKHAs, over at least 1 year. Ventricular enlargement, another characteristic of SHRs, was observed in adult WKHTs after the onset of hypertension; however, ventricles were already enlarged in normotensive WKHAs at 6 wk. The emergent behavioral profile of WKHAs indicates that they retain the hyperactivity trait and hyperreactivity to stress, and not some of the other behaviors of SHRs, such as poor habituation. Studies in WKHTs suggest that they are an improvement over SHRs as a model of genetic hypertension as they lack some prominent behavioral abnormalities. Nevertheless, the four genetically related strains (WKHA, WKHT, SHR, and WKY), used together, are considered most appropriate for seeking correlations of biological differences with either hypertension or hyperactivity.

scholarly journals Biomarkers responses in fish (Atherinella brasiliensis) of paranaguá bay, southern Brazil, for assessment of pollutant effects

2013 ◽  
Vol 61 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Ciro Alberto de Oliveira Ribeiro ◽  
Alberto Katsumiti ◽  
Patrícia França ◽  
Jocieli Maschio ◽  
Eliandra Zandoná ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Protected Areas ◽  
Aquatic Organisms ◽  
Southern Brazil ◽  
Paranaguá Bay ◽  
Fuel Oils ◽  
Polycyclic Aromatic ◽  
Biochemical Genetic ◽  
Autumn And Winter ◽  
The Impact

Paranaguá bay is a complex estuary located in southern Brazil containing three protected areas listed by UNESCO. Historically, the estuary has been affected by urban, industrial, agricultural and harbor activities, and occasional accidents. Specifically, the explosion of the Chilean ship Vicuña in December 2004 spilled methanol and crude and fuel oils which affected both protected and non-protected areas. The present study sought to investigate the pollution threat to aquatic organisms in order to evaluate the potential effects of pollutants. One hundred and twenty adult fish Atherinella brasiliensis were collected from different sites within Paranaguá estuary, including the harbor and open ocean, during summer, autumn and winter of 2005. Among the biomarkers, the somatic index, chemical analysis of bile, biochemical, genetic and morphological parameters were considered. Chemical analysis of bile showed a continuous bioavailability of polycyclic aromatic hydrocarbons (PAHs) according to proximity to the harbor site. The histopathological findings have demonstrated aconsiderable incidence of severe pathologies in the liver and gills, corroborated by biochemical disturbances and genetic damage. These findings indicate that more studies are necessary to evaluate both water quality and fish health so as to permit a better analysis of the impact of pollution in Paranaguá estuary.

scholarly journals Seasonal variation of the plerocercoid ligula intestinalis (L) observed in roach (Rutilus rutilus, L) from the yenice irrigation pond, Çanakkale, Turkey

2004 ◽  
Vol 58 (1-2) ◽  
pp. 127-133 ◽  
Author(s):  
Cemal Oguz ◽  
Öztürk Oguz ◽  
Hayati Güre
Keyword(s):  
Seasonal Variation ◽  
Parasite Species ◽  
Abdominal Cavity ◽  
Rutilus Rutilus ◽  
The Other ◽  
Host Fish ◽  
Roach Rutilus Rutilus ◽  
Mean Intensity ◽  
Ligula Intestinalis ◽  
Irrigation Pond

This study was carried out at the Yenice Irrigation Pond between October 1999 and October 2000. For this study 368 roach (Rutilus rutilus) were examined and 37 parasites and 93 Ligula intestinalis were found in the abdominal cavity of the host (prevalence 10.1%, mean intensity 2.51 specimens/fish). Based on season, the highest number of infected fish occurred during summer (33.3%, 4 parasite/fish), and during the other season the mean intensity of infection was relatively low (prevalence 3.3%, 1 specimens/fish). On the other hand, the parasite species was determined especially on small and medium host fish sizes (2.17-100%). Basic criteria for the assessment of the parasite species of host fish were the general parameters related to parasite populations, which are prevalence, mean intensity, seasonal variation, and relationship between host size and infection.

scholarly journals Extraordinary morphological changes in valve morphology during the ontogeny of several species of the Australian ostracod genus Bennelongia (Crustacea, Ostracoda)

2013 ◽  
Author(s):  
Patrick De Deckker ◽  
Koen Martens
Keyword(s):  
Adult Stage ◽  
Morphological Changes ◽  
The Other ◽  
Left Valve ◽  
Ventral Region ◽  
Valve Morphology ◽  
Other Hand ◽  
Early Instar ◽  
Juvenile Stages

Ostracods belonging to the genus Bennelongia differ much in valve morphology between adults and juveniles. Adult valves are asymmetrical, characterised by a beak-like feature in the antero-ventral region of the left valve, and, with some notable exceptions, mostly have smooth or weakly-ornamented valves. Juvenile specimens, on the other hand, have valves that are almost symmetrical, with no beak-like feature and are often heavily ornamented.We have examined the last 3 - 4 juvenile stages of 6 Bennelongia species from 5 different lineages, in order to decipher the types of external valve ornamentation and their recurrences during ontogeny and across lineages. It is clear that ornamentation is more prevalent at the early instar stages compared to the last 2 pre-adult stages, and especially when compared to the adult stage itself.We also examined the surprising presence of a calcified inner lamella with a prominent inner list in the pre-adult stages of Bennelongia species, that is usually absent in juveniles of other ostracods, thus questioning if heterochronic processes have provided an intermediate valve morphology between the simple (normal) cypridinid juvenile state and the heavily derived and modified state of adult Bennelongia.We discuss the possible (speculative) functionality of the ornamentation in juveniles.

scholarly journals Universal Evolutionary Model for Periodical Species

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Eric Goles ◽  
Ivan Slapničar ◽  
Marco A. Lardies
Keyword(s):  
Fitness Function ◽  
Evolutionary Model ◽  
Prime Numbers ◽  
Life Cycles ◽  
The Other ◽  
Exclusion Principle ◽  
Greatest Common Divisor ◽  
Predator Prey ◽  
Integer Multiple ◽  
New Period

Real-world examples of periodical species range from cicadas, whose life cycles are large prime numbers, like 13 or 17, to bamboos, whose periods are large multiples of small primes, like 40 or even 120. The periodicity is caused by interaction of species, be it a predator-prey relationship, symbiosis, commensalism, or competition exclusion principle. We propose a simple mathematical model, which explains and models all those principles, including listed extremal cases. This rather universal, qualitative model is based on the concept of a local fitness function, where a randomly chosen new period is selected if the value of the global fitness function of the species increases. Arithmetically speaking, the different interactions are related to only four principles: given a couple of integer periods either (1) their greatest common divisor is one, (2) one of the periods is prime, (3) both periods are equal, or (4) one period is an integer multiple of the other.

New species of Sargassum-boring Limnoria Leach, 1814 (Crustacea, Isopoda, Limnoriidae) from Japan

Zootaxa ◽  
2021 ◽  
Vol 4970 (1) ◽  
pp. 119-130
Author(s):  
HIROKI YOSHINO ◽  
YURIKO KAMBARA ◽  
SHOTA KAJIWARA ◽  
TAKESHI A. OHSAWA
Keyword(s):  
New Species ◽  
The Other ◽  
Coi Gene ◽  
Congeneric Species ◽  
Japanese Species ◽  
Mitochondrial Coi ◽  
Chiba Prefecture ◽  
Mitochondrial Coi Gene ◽  
Mandibular Palp ◽  
Coi Sequences

A new marine Sargassum-boring species of Limnoria (Limnoriidae) is described on the basis of specimens obtained at Kamogawa-shi, Chiba Prefecture, Japan. Limnoria aspera sp. nov. shares a reduced mandibular palp to a seta, algal-feeding, and the clavate shaped epipod of the maxilliped with the other species of non-mandibular-palp group. L. aspera sp. nov. differs morphologically from the congeneric species by secondary unguis of pereopods and unique carinae of pleonite 5 and pleotelson. We describe the sequences of the mitochondrial COI gene and the nuclear 28S rDNA gene. L. aspera sp. nov. differs by 14.2–18.0% in p-distance based on COI sequences from other Japanese species, L. furca and L. nagatai. 

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