scholarly journals Latitudinal cline in a colour pattern polymorphism in the Australian grasshopper Phaulacridium vittatum

Heredity ◽  
1981 ◽  
Vol 47 (1) ◽  
pp. 111-119 ◽  
Author(s):  
John M Dearn
Keyword(s):  
Colour Pattern ◽  
Latitudinal Cline ◽  
Pattern Polymorphism

Colour Pattern Polymorphism in the Grasshopper Phaulacridium Vittatum. I. Geographic Variation in Victoria and Evidence of Habitat Association.

1984 ◽  
Vol 32 (2) ◽  
pp. 239 ◽  
Author(s):  
JM Dearn
Keyword(s):  
Geographic Variation ◽  
Habitat Associations ◽  
Colour Pattern ◽  
Habitat Association ◽  
Latitudinal Cline ◽  
Selective Constraints ◽  
South Eastern ◽  
Eastern Australia ◽  
Pattern Polymorphism ◽  
Forest Habitats

The frequencies of the 3 colour pattern morphs (plain, striped and incomplete-striped) in samples of Phaulacridium vittatum (Sjost). from pasture sites in Victoria, Australia, did not conform to the pattern predicted by the latitudinal cline in morph frequencies previously described in south-eastern Australia. Data from 2 transects across pasture-forest boundaries revealed the existence of habitat associations, with forest habitats having a higher frequency of the plain morph. The proximity of some pasture populations to forests may explain some of the variation in morph frequencies observed among pasture sites. However, the frequency of the striped morph was relatively low in all the populations examined; this suggests that there are strong selective constraints on the frequency of striped individuals.

Life history and reproductive ecology of White's skink, Egernia whitii

2005 ◽  
Vol 53 (6) ◽  
pp. 353 ◽  
Author(s):  
DG Chapple
Keyword(s):  
Life History ◽  
Litter Size ◽  
Reproductive Ecology ◽  
Climatic Conditions ◽  
Colour Pattern ◽  
Offspring Size ◽  
Adult Sex Ratio ◽  
Pattern Polymorphism ◽  
Comparison Of The Results ◽  
Colour Morphs

The life history and reproductive ecology of White’s skink, Egernia whitii, was examined in a population in the Australian Capital Territory using both field and genetic studies. Colour pattern polymorphism was evident within the population, with both patterned and plain-back morphs present. Lizards typically took 3 years to reach sexual maturity, with the size at maturity being ~75 mm snout–vent length (SVL) in both sexes. There was an even overall adult sex ratio, although a slight female-bias was evident in plain-back individuals. Sexual dimorphism was evident, with males having longer and wider heads, and females having larger body size. Females generally bred annually, with mating occurring in September–October and parturition in late January–February, although the litter was produced over several days (2–10 days, mean 4 days). Litter size ranged from one to four (mean of 2.5). There was a significant relationship between maternal SVL and both litter size and relative clutch mass, but these trends were not consistent between colour morphs. An inverse relationship between litter size and offspring size (SVL and mass) was found. Comparison of the results with previous investigations of E. whitii indicates substantial geographic variation in life-history traits that is presumably associated with latitudinal variation in climatic conditions.

A gynandromorphic grasshopper produced by double fertilization

1968 ◽  
Vol 16 (1) ◽  
pp. 101 ◽  
Author(s):  
MJD White
Keyword(s):  
Natural Populations ◽  
Colour Pattern ◽  
Double Fertilization ◽  
Female Side ◽  
Zygote Nucleus ◽  
Male Side ◽  
Pattern Polymorphism ◽  
Two Sides

An individual of the large grasshopper Valanga irregularis (Walker) which exhibited bilateral gynandromorphism, is described. The entire right side was female, the left side being male. The colour pattern on the two sides was completely different, the male side corresponding to the concolorous phenotype, the female side to the contrasty one. The gonad was an undeveloped ovotestis, the testicular part being XO (2n = 23). There are two obvious explanations of this gynandromorph: (1) that a single XX zygote nucleus gave rise to XX and XO nuclei through loss of an X; in this case we would be dealing with a sex-linked pattern polymorphism, the gene for the contrasty morph being dominant to the concolorous allele; (2) that the gynandromorph arose from a binucleate egg, as a result of double fertilization. Data on the frequency of the morphs in the two sexes, in natural populations, do not support the first hypothesis, and it is concluded that the second one must be correct.

Unrecognized species diversity and new insights into colour pattern polymorphism within the widespread Malagasy snake Mimophis (Serpentes: Lamprophiidae)

2017 ◽  
Vol 16 (3) ◽  
pp. 229-244 ◽  
Author(s):  
Sara Ruane ◽  
Edward A. Myers ◽  
Kahmun Lo ◽  
Sara Yuen ◽  
Rachel S. Welt ◽  
...  
Keyword(s):  
Species Diversity ◽  
Colour Pattern ◽  
Pattern Polymorphism

The colour/pattern polymorphism of Philaenus spumarius (Hemiptera: Cercopidae) in the north-western Black Sea region of Turkey

Biologia ◽  
2010 ◽  
Vol 65 (2) ◽  
Author(s):  
Selcuk Yurtsever ◽  
Nilgun Akdeniz ◽  
Burcu Karahalil
Keyword(s):  
Black Sea ◽  
Colour Pattern ◽  
Black Sea Region ◽  
Philaenus Spumarius ◽  
The North ◽  
The Common ◽  
Pattern Polymorphism ◽  
North Western

AbstractThe heritable elytral colour/pattern polymorphism of Philaenus spumarius in north-western Black Sea region of Turkey was investigated. A total of 2,530 adult spittlebugs, 1,020 females and 1,510 males were collected and analysed in terms of the 11 most common colour forms. Nine different phenotypes, expressed by six different alleles, were determined: populi (POP), typicus (TYP), trilineatus (TRI), marginellus (MAR), flavicollis (FLA), leucocephalus (LCE), gibbus (GIB), albomaculatus (ALB), and leucophtalmus (LOP). The common phenotypes lateralis (LAT) and quadrimaculatus (QUA) of previous studies were not encountered at all. The predominant phenotype was TYP (63%) in females and males followed by POP (31%). TRI (4%) and melanics (5%) were at close proportions. However, only one site had nine phenotypes altogether. The majority of the sites had only the POP and TYP morphs. The melanic forms were found only in females.

SELECTION AND THE MAINTENANCE OF A COLOUR PATTERN POLYMORPHISM IN THE GREEN SWORDTAIL (XIPHOPHORUS HELLERI)

Behaviour ◽  
2001 ◽  
Vol 138 (4) ◽  
pp. 467-486 ◽  
Author(s):  
Dierk Franck ◽  
Marion Dikomey ◽  
Manfred Schartl
Keyword(s):  
School Choice ◽  
Colour Pattern ◽  
Clear Water ◽  
Variable Environment ◽  
Xiphophorus Helleri ◽  
Black Spots ◽  
Malignant Skin Tumors ◽  
Malignant Skin ◽  
Pattern Polymorphism ◽  
Number Of Individuals

AbstractMany Xiphophorus populations include a number of individuals with black spots on body sides or fins. In many cases such spots are composed of extremely large melanophore cells, the so-called macromelanophores. Macromelanophore pattern polymorphism is known in 10 out of 22 Xiphophorus species. In at least 8 species alleles of the macromelanophore determining locus Mdl are intimately linked to a dominant oncogene, ONC-Xmrk, which can give rise to malignant skin tumors (melanoma). We present, for the first time, evidence that macromelanophore pattern polymorphisms may be maintained by selection in a seasonally variable environment. In school-choice experiments single Xiphophorus helleri females spent more time with groups of spotted females than with non-spotted females under turbid, but not under clear water conditions. Similarly, receptive females preferred spotted males in turbid, but not in clear water. Thus, in nature, when the water becomes turbid after heavy rainfalls, school mates and reproductive partners can evidently find each other more easily with the help of macromelanophore spotting patterns. Intrasexual selection seems to be irrelevant because spotted and non-spotted males were equally successful in competition experiments. A genetic hitchhiking scenario is discussed which could explain the fact that the potentially injurious tumor gene ONC-Xmrk has been maintained in the genus Xiphophorus over a period of millions of years by its close linkage to positively selected macromelanophore alleles.

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