Pigmented Spots Research Articles

Morphological and molecular identification of an introduced alien sea squirt (Tunicata: Ascidiacea) in Korea

Sea squirts were collected from shallow waters of 0.5–5.0 m depth at 27 harbors or ports in Korea: 14 harbors in the East Sea, 10 harbors in the Korea Strait, and three harbors in the Yellow Sea. Ciona intestinalis was identified as an introduced alien species and was compared with the Asian native C. savignyi, which was first reported in Korea. Four distinct morphological differences are recognized between these two species: 1) shape of pigment spots on branchial and atrial siphons, 2) flecks of body, 3) color or shape of the tip of the vas deferens, and 4) thickness and transparency of the body wall. Phylogenetic relationships of these species are examined through molecular analysis based on 720 bp of mtCOI gene sequences. Korean C. intestinalis belong to Type A.

Phenotypic variation and identification of Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) in China.

Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is an invasive mealybug that seriously damages cotton and other important crops. In previous studies in China, the presence of two submedian longitudinal lines of pigmented spots on the dorsum of adult females frequently has been used to identify this species. However, the present study records the occasional absence of pigmented spots in a sample from Guangxi province, China. Specimens without pigmented spots showed all the molecular and morphological characters that separate P. solenopsis from the similar species P. solani Ferris, especially the distribution of multilocular disc pores. In different geographic populations of P. solenopsis in China, mitochondrial COI and nuclear 28SrDNA genes are very similar (99.8-100%), indicating that they are conspecific. For COI, the genetic distance between P. solenopsis and P. solani is more than 3%. A map of the distribution of P. solenopsis in China is given. To help identify both pigmented and non-pigmented P. solenopsis accurately, an identification key to the 16 species of Phenacoccus found in China is provided. The key also identifies five potentially invasive Phenacoccus species not yet established in China, in case they get introduced there.

Sexy faces in a male paper wasp.

Sexually selected signals are common in many animals, though little reported in social insects. We investigated the occurrence of male visual signals mediating the dominance relationships among males and female choice of sexual partner in the paper wasp Polistes simillimus. Males have three conspicuous, variable and sexually dimorphic traits: black pigmentation on the head, a pair of yellow abdominal spots and body size differences. By conducting behavioral assays, we found that none of the three visual traits are associated with male-male dominance relationship. However, males with higher proportion of black facial pigmentation and bigger yellow abdominal spots are more likely chosen as sexual partners. Also, after experimentally manipulating the proportion of black pigment on males' face, we found that females may evaluate male facial coloration during the choice of a sexual partner. Thus, the black pigmentation on P. simillimus male's head appears to play a role as a sexually selected visual signal. We suggest that sexual selection is a common force in Polistes and we highlight the importance of this group as a model for the study of visual communication in insects.

On the ocular findings in ochronosis: a systematic review of literature.

BackgroundOchronosis/Alkaptonuria is a tyrosine metabolism disorder where accumulation of homogentisic acid, in eye, skin, cartilage and several other connective tissues leads to a black pigmentation of the affected tissues. It is autosomal-recessive inherited in men with a frequency of 1-9/1,000,000. While it is clear that pigment deposits lead to joint destruction, renal stone formation and cardiac valvulopathy respectively, the significance of ocular findings is still unclear. We therefore aim to evaluate the frequency and clinical significance of ocular findings in ochronosis and discuss possible therapeutic options.MethodsSystematic review of literature via Medline and Web of Science. Only case reports in English, German, French, Spanish or Italian documenting detailed ophthalmologic examination were included.ResultsOur search revealed 36 case reports including 40 patients. Average age at the onset of ocular signs was 40.6 years. The most frequent sign was symmetric brown sclera pigmentation present in 82.5 percent of the patients. “Oil-drops”, brown pigment spots in the limbus are generally considered pathognomonic but were a little less frequent (75 percent). Vermiform pigment deposits at the level of the conjunctiva or increased conjunctival vessel diameter is also frequent. We found an increased incidence of central vein occlusion and elevated intraocular pressure going along with chamber angle hyperpigmentation. Another condition observed twice is rapid progressive astigmatism attributable to corneoscleral pigment accumulation.ConclusionOur observations suggest that ocular findings are of double relevance. First, characteristic ocular findings can anticipate the time of diagnosis and second, ocular findings may complicate to various conditions putting sight at risk. Opthalmologists and general physicians should be aware of both. Therapeutic options include protein restriction, administration of high dose vitamin C or nitisonone. Evidence for all of them is limited.

A case of Peutz-Jeghers-type polyp of the duodenum treated endoscopically

The patient was a 67-year-old woman in whom endoscopic retrograde cholangiopancreatography (ERCP) performed to treat choledocholithiasis revealed a 1.5-cm pedunculated polyp in the duodenum in October 2010. Pathological examination of a biopsy specimen showed no evidence of malignancy. In July 2012, the polyp had grown to 3.5 cm in diameter. The head of the polyp was lobular and red, and revealed no irregularity of the surface or vascular pattern on magnifying endoscopy with narrow-band imaging (NBI) . The stalk of the polyp showed no marked differences from the normal duodenal epithelium. Another biopsy specimen revealed arborecent hyperplasia of the muscularis mucosa, and a hamartomatous polyp was suspected. The patient was admitted to the hospital for endoscopic treatment in view of the possibility of malignancy. She underwent polypectomy; her subsequent clinical course was uneventful, and she was discharged from the hospital 8 days after treatment. The resected specimen showed a lobular polyp measuring 34×18×14 mm, and pathological examination confirmed the diagnosis of a hamartomatous polyp. She did not have any family history of Peutz-Jeghers (P-J) syndrome and showed no pigmented spots; therefore, P-J-type polyp was diagnosed. No recurrence or evidence of other polyps was seen on gastrointestinal endoscopy or colonoscopy performed 1 year after the treatment. P-J-type polyps are hamartomatous polyps with the same pathological findings as the polyps associated with P-J syndrome without the family history or pigmented spots. P-J-type polyps can cause bleeding and obstruction, and show potential for malignant transformation; therefore, treatment such as surgery or endoscopic removal is warranted. In addition, other areas of the gastrointestinal tract, including the small intestine, need to be examined to rule out multiple lesions.

Desarrollo larval de Evermannia zosterura (Perciformes: Gobiidae)

Gobiidae is the most specious fish family in the world with almost 2 000 species, however only 11% of them have been described for their larval stages. The entire life cycle information is essential to understand the biology and ecology of this important fish group. Previous studies on zooplankton samples from Ensenada de La Paz, México, have shown the presence of several Gobiidae larvae and juveniles which were identified as Evermania zosterura. The main objective of this work was to describe the larval stages of this species, widely distributed in the Eastern tropical Pacific. The development of E. zosterura larvae was described based on 66 specimens. A total of 53 specimens were used to describe morphometrics and pigmentation patterns, while 13 specimens were cleared and stained, to obtain meristic characteristics. Cleared specimens had 30 to 31 total vertebrae; dorsal-fin elements: IV; 1, 13-14, anal-fin elements: 1, 13-14, and most had pterygiophore formula 4-111100. The combination of these characteristics confirmed these specimens as E. zosterura. The pigment pattern is similar throughout ontogeny. Larvae are characterized by having three to five dendritic melanophores along the post-anal ventral margin, four to nine smaller melanophores along the ventral margin between the isthmus and anus, and one on the midpoint of the dorsal margin of the tail. There is one small pigment spot on the angle of the jaw, and other on the tip of lower lip. There is an elongated internal pigment under the notochord, between the head and gas bladder. Notochord flexion starts near 3.5mm BL and ends at 4.6mm BL; transformalion to the juvenile stage is at about 13.6mm BL. Our conclusion is that the most useful characters to distinguish this species early-larval stages from those of similar species in the area, are the number of myomeres, the large melanophores (approximately uniformly in size) on the post anal ventral margin, and the elongate internal pigment under the notochord, anterior to the gas bladder.

Dieulafoy Lesion: An Uncommon Cause of Esophageal Bleeding

Introduction: A Dieulafoy lesion refers to an abnormally large arteriole that retains the large caliber of its feeding vessel as it approaches the mucosa. It is an uncommon cause of gastrointestinal (GI) bleeding and when identified, is rarely found in the esophagus. Case Report: A 74-year-old African-American male with hypertension, diabetes, hyperlipidemia, chronic kidney disease, and coronary artery disease presented with nausea and dark brown emesis for 1 day. Emergency room assessment included a nasogastric lavage which was positive for 600 mL of dark red bloody aspirate. Urgent esophagogastroduodenoscopy was planned. Visualization of the esophagus revealed a pigmented spot with a protuberance, appearing like a volcano, with ulceration at its tip (Figure 1). This was thought to be arterial bleeding consistent with a Dieulafoy lesion. The lesion was injected with 4 mL of 1:10,000 epinephrine and placement of clips was performed to achieve hemostasis (Figure 2).Figure 1: Esophageal protuberance with ulceration and arterial bleed due to Dieulafoy lesion.Figure 2: Post-endoscopic injection of epinephrine and clip placement.Discussion: Dieulafoy lesions, also termed exulceratio simplex, are twice as common in males as in females and seem to have a predilection for the elderly population. Comorbidities are present in 90% of patients, most frequently cardiopulmonary disease and chronic renal failure. Although they are typically found in the lesser curvature of the stomach (80-95%), esophageal Dieulafoy lesions are rarely reported in the literature. While it accounts for only 1-2% of GI bleeds, the potential for grave outcomes demands heightened surveillance during endoscopic assessment for acute GI bleed.

Description of a new leech species from North America,Helobdella austinensisn. sp. (Hirudinea: Glossiphoniidae), with observations on its feeding behaviour

Freshwater leeches of the genus Helobdella Blanchard 1896 are small, proboscis-bearing glossiphoniids of the family Rhynchobdellidae that have been found worldwide. Over the past three decades, annelid developmental biologists have used several Helobdella species as model organisms. Here we describe a variable taxon, that has been studied extensively, and was formerly labelled as Helobdella sp. robusta” (Austin), as a new species, Helobdella austinensis n. sp. Diagnostic features of this polymorphic species, which has a body length of 13 to 17 mm and a yellow-brown colour, include a characteristic pattern of dark longitudinal stripes with black, conical papillae on the dorsal side of the body, irregularly arranged white pigment spots, and the lack of a nuchal scute. The type locality is Shoal Creek, Austin, Texas, USA. Based on the sequence of part of the mitochondrial gene cytochrome c oxidase subunit I, H. austinensis n. sp. is a defined taxon that differs genetically from other, morphologically similar Helobdella species by 11 to 17 %. Under laboratory conditions, hungry leeches suck body fluids from living freshwater snails, dead (frozen-thawed) Chironomus larvae, and crushed (wounded) crustaceans. Aquatic oligochaetes (Tubifex worms) and living insect larvae are ignored. This specific prey selection is a characteristic feature of H. austinensis, a taxon that differs, based on morphological features, from its relatives of the South American triserialis species complex. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Molecular identification and morphological description of totoaba Totoaba macdonaldi and curvina Cynoscion reticulatus preflexion larvae (Perciformes: Sciaenidae)

Preflexion larvae of Sciaenidae taxa collected in the upper Gulf of California on 29 March 2011, were identified as Totoaba macdonaldi (n = 4; notochord length 2.83 mm ± 0.22), an endemic species, and Cynoscion reticulatus (n = 11; notochord length 4.51 mm ± 0.47) on the basis of genetic divergence of partial sequences of 16S rRNA gene (448 base pairs) of mitochondrial DNA. Molecular identification was supported by clustering of preflexion larvae with adult specimens in the phylogenetic analysis, intraspecific ( 1 %) genetic divergences. Detailed observations allowed morphological descriptions and suggested diagnostic pigmentation in ventral midline of gut, one in T. macdonaldi, but three to four pairs in C. reticulatus; no spots were present on the dorsal tail in T. macdonaldi, but one or two were present in C. reticulatus. Totoaba macdonaldi had more than 20 pigment spots on the ventral tail, but there were only six in C. reticulatus. These larvae descriptions would be useful to identify areas and period of spawning of both species in ichthyoplankton studies.

Effects of experimental calcium availability, egg parameters and laying order on Great TitParus majoreggshell pigmentation patterns

Many bird species lay eggs speckled with protoporphyrin-based spots, however, for most of them the function of eggshell spotting is unknown. A plausible hypothesis is that protoporphyrin might have a structural function in strengthening the eggshell and is therefore deposited when calcium is scarce. In this study, we experimentally provided Great Tit Parus major females with supplemental calcium to examine its effect on the protoporphyrin-based maculation of their eggs. In addition, we studied variation in eggshell pigmentation patterns in relation to other egg parameters and laying order. Calcium-supplemented females laid larger eggs but shell thickness was not significantly affected by the treatment. Calcium supplementation may reduce the time and energy females devote to searching for calcium-rich material, so that they can collect more nutrients and so lay larger eggs. Furthermore, pigment darkness was associated with egg volume and shape, which suggests that female quality and environmental food availability may also influence the shell pigmentation pattern. Within clutches, later-laid eggs had larger and darker spots that were distributed more unevenly on the shell surface. This within-clutch pattern could be explained by the increase in egg volume and egg shape and a decline in shell thickness with egg-laying order, which characteristics were all related to shell-spotting pattern. Eggs with a coronal ring had thinner shells, but pigment intensity and spot size were not related to shell thickness. Thus, our results suggest that concentrated spotting distribution may have a mechanical function, supporting the structural-function hypothesis.

Pseudomelanosis Duodeni

Pseudomelanosis duodeni (PD) manifests as speckled black pigmentation or black spots in the duodenal mucosa. PD is a rare, benign condition in which dark pigment accumulates in macrophages located in the lamina propria. There is no known association with pigmentation elsewhere in the gastrointestinal tract or with the use of laxatives. PD is more common in patients with hypertension, chronic renal failure, diabetes mellitus, history of upper gastrointestinal bleeding, and oral iron intake. The pigment is usually located in the lysosomes of mucosal macrophages. Histochemical studies and electron probe microanalysis suggest that several pigments may result in this endoscopic appearance, including lipomelanin, ceroid, iron sulfide, and hemosiderin. A case of PD with angioectasia is presented. Careful endoscopic examination is needed to rule out other duodenal lesions in patients with PD. This article is part of an expert video encyclopedia.

Endoscopic Treatment of Upper Gastrointestinal Ulcer Bleeding

Peptic ulcer disease is the most common cause of upper gastrointestinal (GI) bleeding. In most of the cases, bleeding from a peptic ulcer stops spontaneously. Arterial diameters in bleeding ulcers can measure up to 3.45 mm, but in most cases the diameter of the bleeding artery is small (< 2 mm). High-dose intravenous proton pump inhibitors after endoscopic therapy for a bleeding ulcer reduce recurrent bleeding risk and surgery. The endoscopic appearance of an ulcer provides important prognostic information. Clean based ulcers and ulcers with a flat pigmented spot have low rebleeding risks. Major stigmata of hemorrhage (an adherent clot, a visible vessel, or active bleeding) are associated with high rebleeding risks. Endoscopic treatment in patients with high-risk stigmata results in improved outcomes. Common endoscopic techniques and the devices used to treat upper GI ulcer bleeding, including injection therapy, thermal coagulation, endoclip application, and hemostatic powder spray are described in the given video. Different clinical scenarios are presented. This article is part of an expert video encyclopedia.

The effect of vaccination, ploidy and smolt production regime on pathological melanin depositions in muscle tissue of Atlantic salmon, Salmo salar L

The presence of melanin in muscle fillets of farmed salmon represents a considerable quality problem for the salmon industry with major economic concerns. In this study, we have examined the presence of abnormal pigmentation in vaccinated versus unvaccinated Atlantic salmon, Salmo salar L., and evaluated possible differences between diploid and triploid fish. Furthermore, the impact of the smolt production regime at ambient (4.5°C) versus elevated temperature (16°C) was investigated. Pigmented muscle spots were analysed for the expression of genes involved in melanization (tyrosinase gene family) and immune-related response in addition to morphological investigations. The proportion of fish with intramuscular melanin deposits was not significantly different between vaccinated and unvaccinated fish, regardless of ploidy. However, an interaction between vaccination and smolt regime was shown, where smoltification at elevated temperature after vaccination increased the number of affected individuals compared with vaccination followed by simulated natural smoltification. Furthermore, there were overall more fish with melanin spots amongst the triploids compared with their diploid counterparts. Transcription of the tyrosinase gene family confirmed an onsite melanogenesis in all pigment spots. The histological examination and the expression of the immune-related genes revealed a chronic polyphasic myopathy that was not affected by vaccination, ploidy or smolt production regime.

Hyperpigmentation in North Sea dab Limanda limanda. I. Spatial and temporal patterns and host effects

Hyperpigmentation is a term describing a specific pigment anomaly affecting common dab Limanda limanda in the North Sea and, less frequently, in adjacent areas, e.g. the English Channel, Irish and Celtic Seas, western Baltic Sea and Icelandic waters. Other North Sea flatfish species are also affected, but at a markedly lower prevalence. The condition is characterised by the occurrence of varying degrees of green to black patchy pigment spots in the skin of the upper (ocular) body side and pearly-white pigment spots in the skin of the lower (abocular) body side. In the course of fish disease monitoring programmes carried out by Germany and the UK (England and Scotland), a pronounced spatial pattern of hyperpigmentation has been detected in the North Sea. An increase in prevalence has been recorded in almost all North Sea areas studied in the past 2 decades. The prevalence recorded in hot spot areas of the condition increased from 5 to >40% between 1988 and 2009. Analysis of the German data indicates that the prevalence and intensity (degree of discolouration) of hyperpigmentation increase with size and age, indicating a temporal progression of the condition with size and age. Intense hyperpigmentation is associated with increased growth (length) and decreased condition factor. Potential causes of the condition (UV-B radiation nutrition, water temperature increase, demographic changes) and, in particular, of the spatial/temporal patterns recorded as well as the relationship to host-specific factors (sex, age, length, growth, condition factor) are discussed.

Evaluation of Free Radical-Scavenging Activity of Sea Urchin Pigments Using HPTLC with Post-Chromatographic Derivatization

Chromatographic separation, analysis of in situ radical-scavenging activity, and quantitative analysis of green sea urchin shell pigments were carried out by online HPTLC-DAD and HPTLC-DPPH methods. Methanol:chloroform:acetic acid:water (11:50:5:2, v/v) was selected as the best mobile phase on silica gel plates for the separation of the pigments. Two pigment spots, S1 and S2, were observed on the TLC plates, while echinochrome A was not detected in the pigment extract of green sea urchin shells. Based on the estimated ID50 values, the antiradical activity was S2 (0.043 μg) > S1 (0.058 μg) > echinochrome A (0.134 μg).

Spontaneous melanotic lesions in axillary seabream, Pagellus acarne (Risso)

In this article, we describe spontaneous melanotic lesions in the skin of axillary seabream, Pagellus acarne (Risso), from a defined area of the Portuguese Coast, located in Cabo da Roca and Foz do Arelho. The lesions corresponded to the black pigmentation spots on the skin of the head, fins, lips and conjunctiva and, additionally, black nodules on the skin of the head and lips. In some specimens, the nodular formations in the head changed their anatomical conformation. Histologically, there were melanophores scattered along the basement membrane or forming aggregates in the dermis, infiltrating the subcutaneous tissue but not invading the adjacent muscle tissue. The aim of this study was to characterize the macroscopic and microscopic features of the pigmented lesions. These fish show sessile hyperpigmented lesions (spots) that correspond to proliferative lesions of melanophores in the dermis and nodular lesions that correspond to neoplastic lesions, melanophoromas. The melanophores in such lesions showed high concentration of melanin in the cytoplasm, moderate pleomorphism and compact distribution throughout all of the dermis.

Efficacy of a Novel Treatment Serum in the Improvement of Photodamaged Skin

SynopsisA novel treatment serum formulated to target multiple pathways in the anti-ageing cascade was tested both in vitro and in clinical settings. In vitro testing was performed to assess the ability to stimulate key proteins and genes fundamental to the anti-ageing cascade. The antioxidant potential of the formulation was studied in a UV-irradiation clinical study. A 12-week, open-label, single-centre study was conducted to determine whether this uniquely formulated topical treatment serum could improve visible signs of facial photodamage. Clinical evaluations showed statistically significant reductions in fine wrinkles and coarse wrinkles and improvements in skin texture, tone and radiance starting at week 4 with continued improvements at weeks 8 and 12. Subject self-assessments confirmed that the beneficial effects of the treatment serum were readily observed by the users. The treatment serum was well tolerated with no treatment-related adverse events reported during the 12-week study. Use of this novel treatment serum produced significant improvements in the visible signs of facial photodamage.RésuméUn nouveau sérum de traitement conçu pour cibler de multiples voies dans la cascade anti-âge a été testé à la fois in vitro et dans les conditions cliniques. Les tests in vitro ont été réalisés afin d'évaluer la capacité de stimuler les protéines et les gènes clés fondamentales de la cascade anti-vieillissement. Le potentiel antioxydant de la formulation a été étudié dans une étude clinique utilisant le rayonnement UV. Une étude de douze semaines, en mode ouvert, monocentrique a été menée afin de déterminer si ce sérum spécialement formulé pour le traitement topique peut améliorer les signes visibles du photo-vieillissement du visage. Des évaluations cliniques ont montré une réduction statistiquement significative des rides et des ridules secondaires et l'amélioration de la texture de la peau, du tonus et d'éclat à partir de la semaine 4 avec des améliorations continues aux semaines 8 et 12. Les autoévaluations par les sujets ont confirmé que les effets bénéfiques du sérum de traitement étaient facilement observés par les utilisateurs. Le sérum de traitement a été bien toléré avec aucun événement indésirable rapporté au cours de l'étude de 12 semaines. L'utilisation de ce nouveau sérum de traitement produit des améliorations significatives dans les signes visibles du photovieillissement du visage.

From landing lights to mimicry: the molecular regulation of flower colouration and mechanisms for pigmentation patterning.

Flower colour is a key component for plant signaling to pollinators and a staggering variety of colour variations are found in nature. Patterning of flower colour, such as pigment spots or stripes, is common and is important in promoting pollination success. Developmentally programmed pigmentation patterns are of interest with respect to the evolution of specialised plant-pollinator associations and as models for dissecting regulatory signaling in plants. This article reviews the occurrence and function of flower colour patterns, as well as the molecular genetics of anthocyanin pigmentation regulation. The transcription factors controlling anthocyanin biosynthesis have been characterised for many species and an 'MBW' regulatory complex of R2R3MYB, bHLH and WD-Repeat proteins is of central importance. In particular, R2R3MYBs are key determinants of pigmentation intensity and patterning in plants. Progress is now being made on how environmental or developmental signal pathways may in turn control the production of the MBW components. Furthermore, additional regulatory proteins that interact with the MBW activation complex are being identified, including a range of proteins that repress complex formation or action, either directly or indirectly. This review discusses some of the recent data on the regulatory factors and presents models of how patterns may be determined.

A Placebo-Controlled Study Demonstrates the Long-Lasting Anti-Aging Benefits of a Cream Containing Retinol, DihydroxyMethylChromone (DMC) and Hyaluronic Acid

Retinol is an ingredient used in cosmetic products for reducing the appearance of the signs of aging and photo-damage. Currently, most of these products contain 0.1% of retinol. However, at this concentration, some irritation can occur. We have evaluated in vitro and in a clinical study the potential efficacy of a combination of actives to improve the facial skin aging signs while using low concentration of retinol. We demonstrated, in vitro, that a chromone derivative, 5,7-di-hydroxy-2-methyl chromone (DMC), is able to enhance the collagen synthesis in culture of normal human dermal fibroblasts. The enhancement of retinol anti-wrinkle efficacy by DMC was confirmed in a small scale clinical trial. Specifically, a product associating low concentration of retinol (0.04%) and DMC (0.1%) in combination with low molecular weight hyaluronic acid fragments (50,000 Dalton of average molecular weight) has been applied topically for 8 weeks. Clinical results show significant improvement of various signs of facial skin aging such as wrinkles, pigmentary spots, tone unevenness, dullness and the overall photo-damage score. Improvements were still visible 4 weeks after the cessation of the test product application. This study demonstrates that significant lasting improvement of facial skin aging can be obtained with well tolerated low concentration of retinol when adequately formulated with other anti-aging ingredients.

Eggshell spotting does not predict male incubation but marks thinner areas of a shorebird's shells

Many birds lay eggs speckled with black or reddish-brown spots of protoporphyrin pigment, but the function of these spots is debated. Two recent hypotheses have received considerable attention. Under the “signaling-function hypothesis,” speckling reflects female quality and influences allocation of male parental care; under the “structural-function hypothesis,” the speckles strengthen the eggshell when calcium is scarce. The evidence for each is taxonomically uneven. For instance, evidence for the signaling-function hypothesis comes from cavity-nesting and uniparentally incubating species in which the viewing conditions and possibilities for males to assess the speckling are limited, and male response to speckling is indirect (i.e., female-feeding) or postponed (i.e., chickfeeding). We tested the predictions of both hypotheses in a biparentally incubating ground-nesting shorebird, the Northern Lapwing (Vanellus vanellus), in which the potential for a direct male response to eggshell speckling exists and visual inspection of the eggs is not hindered by light availability in a nest cavity. The speckling parameters (spot intensity, distribution, and cover) were repeatable within Northern Lapwing clutches, a requirement for a sexually selected signal, but we found no relationship between male incubation and speckling. However, the spots were associated with thinner areas of eggshell, which strongly supports the suggestion of a structural (strengthening) function. Our results do not support the signaling-function hypothesis of eggshell speckling, but extend the structural-function hypothesis and prior findings (that speckling occurs primarily at thinner areas of the shell) to other avian taxa. Furthermore, if the generally accepted view that Northern Lapwing eggs are cryptically marked is correct, our findings suggest that more than one significant function can drive the evolution of avian eggshell pigmentation.