Abdomen Colour Research Articles

Female preference for males with lower pattern contrast follows Weber's law of proportional processing in jumping spiders

Abstract According to Weber's law of proportional processing, perceptual discrimination between stimuli of different magnitudes is based on their proportional differences in magnitude (not absolute differences). Proportional processing operates in various sensory modalities and behavioural contexts. However, whether female mate preference for colour patterns in animals follows Weber's law of proportional processing remains untested. We addressed this research gap using the jade jumping spider, Siler semiglaucus, whose males exhibit remarkable sexually selected colour patterns and whose females show preferences for males with low abdomen pattern contrast (pattern contrast is defined as the spatial feature of the relative abundance of two adjacent colour patches). By manipulating the dorsal abdomen colour patterns of S. semiglaucus males, we created males with varying abdomen pattern contrasts. We then assessed female preference for males that varied in both absolute and proportional differences in pattern contrast. We found that females preferred males with lower abdomen pattern contrasts and discriminated between males based on both absolute and proportional differences in pattern contrast. While proportional difference alone was not a significant predictor of female mate‐choice, discrimination based on proportional difference coupled with absolute difference had a greater influence on female mate preference than absolute difference alone. Hence, our findings suggest that S. semiglaucus female preference for males with lower pattern contrast follows Weber's law, and female discrimination may have the potential to limit the exaggeration of sexually selected colour patterns. Read the free Plain Language Summary for this article on the Journal blog.

Study on milky haemolymph diseases infection in wild and cultured of spiny lobster, Panulirus homarus in Indonesia

Milky Haemolymph Disease in Spiny Lobster (MHD-SL) is the most pathogenic diseases in spiny lobster (Panulirus homarus). Research on MHD-SL infection has not been undertaken in Indonesia. Therefore, present study aims to determine the infection of MHD-SL lobster. In 2016 a total of 240 lobsters for 30 each both from wild and cultured sample were collected from four locations (Candi Kusuma Bay of Bali Island, Gerupuk, Awang, and Telong-Elong Bays of Lombok Island) and in 2019, 50 lobster samples were collected for artificial infection study. While in January 2020, another 40 lobsters were collected from 2 different sites of culture (coastal and offshore cages) within Telong Elong Bay to determine infection of MHD-SL and for transmission study. The MHD-SL diseased was first check by clinical sign and confirmed by PCR-DNA molecular with specific primer of 254 bp. An experimental infection of MHD-SL was carried out by injection and cohabitation. The result showed that infected MHD-SL lobster shows inactive, loose appetite to eat, reddish and white colour of abdomen then moribund and all positive by PCR test. MHD-SL was found only in cultured lobster on the cages located at coastal water and no in the cages located at offshore within Telong-Elong Bay. In the experiment of artificial infection, either by injection or cohabitation, shows clinical sign of MHD-SL appeared at 8 days and all died after 14 days for both treatments. The present study approved that MHD-SL is pathogenic agent belonged to Rickettsia-like bacterium and infection occurred by horizontal transmission.

Are the Yellow and Red Marked Club-Tail Losaria coon the Same Species?

Losaria coon (Fabricius, 1793) is currently comprised of ten subspecies, which were originally described under two names, Papilio coon and P. doubledayi before 1909, when they were combined as one species. The main difference between them is the colour of abdomen and hindwing subterminal spots—yellow in coon and red in doubledayi. Wing morphology, male and female genitalia, and molecular evidence (DNA barcodes) were analysed for multiple subspecies of L. coon and three other Losaria species—rhodifer, neptunus, and palu. Our molecular data support the separation of L. coon and L. doubledayi stat. rev. as two distinct species, with L. rhodifer positioned between them in phylogenetic analyses. Wing morphology and genitalic structures also confirm the molecular conclusions. Our findings divide L. coon into two species occupying different geographic ranges: with L. coon restricted to southern Sumatra, Java, and Bawean Island, while L. doubledayi occurs widely in regions from North India to northern Sumatra, including Hainan and Nicobar Islands. Hence, future conservation efforts must reassess the status and threat factors of the two species to form updated strategies.

The determination of some morphological characteristics of Bursa Oynarı pigeon breed

The aim of this study was to evaluate the morphological characteristics and to describe some quantitative traits of Bursa Oynarı native pigeon breed in Bursa province in Turkey. The study was carried out on a total of randomly selected 43 Bursa Oynarı pigeons (23 males, 20 females). The morphological characteristics (head type, eye colour, head and bib colour, neck blend colour, beak type and colour, head plumage, ventral abdomen colour and claw colour) and the quantitative traits (body weight and morphometric measurements) were determined from both male and female pigeons. The results indicated that the most frequent morphological characteristics of this pigeon breed were round shaped head (72.09%), dusty rose eye colour (67.44%), veiled head/bib colour (37.21%), purple neck blend colour (53.49%), flat-shaped type beak (67.44%), white beak (51.16%), markless head plumage (69.77%), white ventral abdomen colour (93.02%) and white claw colour (95.35%). Sex significantly (P<0.01) affected the quantitative traits such as the body length, leg length and tail length. Male pigeons had higher means of the mentioned traits than those of female pigeons. Over the past few decades, there has been an increased awareness for the conservation of native breeds for their importance to genetic diversity. Thus, studies conducted on native breeds in various species may provide a noteworthy contribution to this purpose.

Revision of AfrotropicalPachycerinaMacquart (Diptera: Lauxaniidae)

The flies of the genus Pachycerina Macquart (Diptera: Lauxaniidae) in the Afrotropical region are taxonomically revised. Eleven species of Pachycerina are found in the Afrotropics (including Madagascar) with seven new species: P. atrimela sp. n., P. gabela sp. n., P. micropunctata sp. n., P. nigrivittata sp. n., P. pellocera sp. n., P. potentilla sp. n., and P. stuckenbergi sp. n. The Afrotropical fauna is relatively conservative in coloration and morphological variation; variation most affecting prefrontal (facial) spot size, abdomen colour, wing infuscation and male terminalia. All male Afrotropical Pachycerina have the protandrium partially fused to tergite 6 and possess simplified genitalia lacking an aedeagus and hypandrium. The absence of the aedeagus is an apparently unusual condition for lauxaniids, only otherwise recorded in Minettia Robineau-Desvoidy (Lauxaniinae) and beetle fly genera (Celyphinae). The male sternite 5 shows notable variability across species and is a useful aid to identification. A generic diagnosis and species identification key to Pachycerina males are provided. Two rearing records of larval Pachycerina from bird nests in South Africa are reported.

Allochronic speciation, secondary contact, and reproductive character displacement in periodical cicadas (Hemiptera: Magicicada spp.): genetic, morphological, and behavioural evidence.

Periodical cicadas have proven useful in testing a variety of ecological and evolutionary hypotheses because of their unusual life history, extraordinary abundance, and wide geographical range. Periodical cicadas provide the best examples of synchronous periodicity and predator satiation in the animal kingdom, and are excellent illustrations of habitat partitioning (by the three morphologically distinct species groups), incipient species (the year classes or broods), and cryptic species (a newly discovered 13-year species, Magicicada neotredecim). They are particularly useful for exploring questions regarding speciation via temporal isolation, or allochronic speciation. Recently, data were presented that provided strong support for an instance of allochronic speciation by life-cycle switching. This speciation event resulted in the formation of a new 13-year species from a 17-year species and led to secondary contact between two formerly separated lineages, one represented by the new 13-year cicadas (and their 17-year ancestors), and the other represented by the pre-existing 13-year cicadas. Allozyme frequency data, mitochondrial DNA (mtDNA), and abdominal colour were shown to be correlated genetic markers supporting the life-cycle switching/allochronic speciation hypothesis. In addition, a striking pattern of reproductive character displacement in male call pitch and female pitch preference between the two 13-year species was discovered. In this paper we report a strong association between calling song pitch and mtDNA haplotype for 101 individuals from a single locality within the M. tredecim/M. neotredecim contact zone and a strong association between abdomen colour and mtDNA haplotype. We conclude by reviewing proposed mechanisms for allochronic speciation and reproductive character displacement.

A REVISION OF THE NORTH AMERICANOPEROPHTERA(LEPIDOPTERA: GEOMETRIDAE)

AbstractThe North American members of the genusOperophteraHübner (Lepidoptera: Geometridae) are revised to include three species:O.brumata(L.),O.bruceata(Hulst), andO.danbyi(Hulst).Operophtera occidentalis(Hulst) is now treated as a subspecies ofO.bruceata. All species are illustrated and characters to distinguish the species are given. The most useful characters for separatingO.brumatafromO.bruceatainclude the following: (1) hindwing dorsal surface with discal dot, which is almost always visible onO.bruceatabut absent fromO.brumata; (2) forewing colour, which is grey-brown or light brown inO.bruceatabut reddish-brown inO.brumata; (3) abdomen colour, which is golden-brown to brown in westernO.bruceatabut brown inO.brumata; and (4) the costa of the forewing ventral surface, which is usually golden-brown inO.bruceatabut brown inO.brumata. The structure of the genitalia of these two species allows hybridization betweenO.bruceatamales andO.brumatafemales, but not vice versa.Hypothesized species interrelationships between palaearctic and nearcticOperophteraare illustrated in a cladogram. Maps for the distribution of each species are also included.

Molting and its control in the female sand lobster Thenus orientalis (Lund)

Thenus orientalis (Lund), the only species of the genus belonging to the family Scyllaridae, is found in the coastal waters of India where it breeds and molts throughout the year, with alternating peaks for molting and reproduction. Females mature at a carapace width (CW) of 7.3 ± 0.1 cm. The molting sequence of T. orientalis in the laboratory was observed and described. The lobster takes ≈ 30–45 min to complete ecdysis. The animal escapes from the old exoskeleton between the thorax and the abdomen. The anterior part, including the thorax, is shed gradually, but, at the end of shedding, the tail comes out quickly. Because of high pigmentation of the pleopods, the molting cycle could only be classified into five major stages (A-E). This, together with the morphological changes such as the appearance of ecdysial sutures and the changing of abdomen colour from yellowish-brown to pink, may help in predicting ecdysis. Eyestalk ablation affects molting more than reproduction; ablated animals molted faster than the controls. Eyestalk ablation in the intermolt condition produced accelerated molting compared to the premolt lobsters. However, there was no effect on ovarian growth although the lobsters with fully mature ovaries deposited eggs on pleopods instantaneously. In contrast, animals with developing ovaries at eyestalk ablation started oosorption.

Morphometric analysis of the populations ofScirtothrips Dorsalishood &amp;Scirto-Thrips Oligochaetus(karny) with reference to the biological and ecological variations

Scirtothrips dorsalis, and S. oligochaetus were described by Hood (1919) and Karny (1926) respectively. Shumsher Singh (1944) considered S. oligchaetus and S. dorsalis as synonymous. Bhatti (1962) treated S. oligochaetus as a valid species based chiefly upon the colour of abdomen, S. dorsalis having dark shadings on intermediate abdominal terga.

Further studies on the genetics of the mimetic butterfly papilio memnon L

Papilio memnon is a Swallowtail butterfly widely distributed in South-East Asia. The females are highly polymorphic and many of them are Batesian mimics. A previous paper gives an account of the mode of inheritance of seventeen of these female forms and here we describe the inheritance of nine from Java and Sumatra, an area we had not investigated before. We have also obtained further information on some of the forms whose modes of inheritance are not clear in the earlier paper. The nine new forms and one of those previously investigated (f. thunbergi ) have been shown to be determined by the same complex locus or super-gene which controls the polymorphism already studied. The results from the present genetic investigation confirm the previous findings in P. memnon and P. dardanus that the resemblance of a form to its model is greater in the gene complex of the race in which the form is found than it is in intra-specific hybrid gene complexes. This suggests that the detailed resemblance of the mimic to its model has been built up gradually by the accumulation of modifiers. Of particular interest in this connexion is the mimic f. achates in Java and South Sumatra in which the heterozygote is a better mimic than the homozygote in the gene complex of its own race. Evidence has also been accumulated on the nature of dominance. Previously, complete dominance was present between most sympatric forms and absent between allopatric ones, both in P. dardanus and P. memnon . In contrast, the forms found in Java and Sumatra show only partial dominance between sympatric forms in most instances. However, in a hybrid gene complex the heterozygotes are even more intermediate. Thus, on these two islands the evolution of dominance has proceeded less far than elsewhere. There is ample evidence for the presence of dominance modifiers, but we are uncertain whether the absence of full dominance results from the modifiers having other, more powerful, selective forces acting upon them, or whether insufficient time has elapsed for full dominance to have evolved. In a complex Batesian mimetic polymorphism the forms must either be controlled by multiple allelomorphs at a single locus, by a group of closely linked loci (a super-gene), or by independent genes having complex epistatic interactions. In both P. dardanus and P. memnon it has been established that super-genes have been evolved. The present study throws further light on the super-gene in P. memnon . We have reason to believe that a number of very rare forms (some of which we have bred) result from crossing over rather than from point mutations, since if mutations were responsible we should have expected some of the patterns to be controlled by loci unassociated with the super-gene. This is not the case. Furthermore, in one instance, a double mutation would be required to explain the pattern. On the assumption that crossing over is the explanation of these rare forms we have postulated five loci. These control the presence or absence of tails ( T ), hind wing pattern ( W ), forewing pattern ( F ), colour of the basal triangle or epaulette on the forewing ( E ), and abdomen colour ( B ). Previously we had deduced that W must lie between T and B . The present study has given independent support to this order and also suggested that neither W nor B lies between E and F , and that T does not lie between W and E , the probable order being TWFEB . If the hypothesis is correct the initial mimic of P. sycorax could have been produced by a single crossover, and f. anceus , the modern mimic, evolved by subsequent minor modifications. In our investigations into the genetics of Batesian mimicry we have found that the polymorphism is controlled by a multiple allelic series at one locus or by a super-gene in P. dardanus , P. memnon and P. polytes (unpublished). This contrasts with the situation in Müllerian mimicry. In order to see whether the evolution of such super-genes is a general phenomenon or whether in other genera of Lepidoptera, and perhaps in other orders, complex epistatic interactions have been developed rather than super-genes, it will be necessary to extend this investigation outside the genus Papilio . We have already started to study Pseudacraea eurytus from Africa, which seems a particularly suitable species to use since the Batesian relationships of its forms are well documented.

Drosophila Andalusiaca, a Polymorphic Species New To Holland

AbstractDrosophila andalusiaca, with one qualified exception hitherto unreported from Holland, has been found in various localities including some of the coastal islands. The sex-limited polymorphism for abdomen colour is also found to occur in some populations, the gene frequencies for the two alleles in one population being roughly equal.