Mauritian coloured nectar no longer a mystery: a visual signal for lizard pollinators

Most floral nectars are clear as water, and the enigmatic coloured nectar in three endemic plant species in Mauritius has puzzled scientists studying it. One hypothesis about the possible ecological function of coloured nectar is that it serves as a visual signal for pollinators. Recent studies have shown that at least two of the three Mauritian plant species with coloured nectar are visited and pollinated by endemic Phelsuma geckos. We here provide experimental evidence for the visual signal hypothesis by showing that Phelsuma ornata geckos prefer coloured over clear nectar in artificial flowers. In flowering plants, coloured nectar could additionally function as an honest signal that allows pollinators to assert the presence and judge the size of a reward prior to flower visitation, and to adjust their behaviour accordingly, leading to increased pollinator efficiency. Our study provides a first step in understanding this rare and intriguing floral trait.     

Two new species of coccidia (Apicomplexa: Eimeriidae) from Madagascar Gekkonids

Two new species of coccidia (Apicomplexa: Eimeriidae) are described from the Madagascar giant day gecko, Phelsuma madagascariensis grandis, and the Golddust day gecko, P. laticauda. Both species of coccidia were found to infect the anterior one-half of the small intestine. Oocysts of Eimeria brygooi n. sp. are spherical or subspherical, 23.0 X 21.3 (18.8-25.2 X 16.4-23.2)micron; shape index (L/W) 1.1 (1.0-1.2). A micropyle, oocyst residuum, and polar granule are absent. Sporocysts are ovoid, 9.2 X 7.9 (8.0-10.0 X 7.2-8.8) micron; shape index 1.2 (1.0-1.3), with a Goussia-type suture; Stieda and substieda bodies are absent. A sporocyst residuum is present, 4.2 X 3.0 (3.2-6.4 X 2.4-4.0) micron. Sporozoites are elongate, with anterior and posterior refractile bodies. This coccidian was found to infect five of six (83%) P. m. grandis and one of five (20%) P. laticauda examined. Oocysts of Isospora gekkonis n. sp. are spherical or subspherical, 24.2 X 22.0 (21.6-26.4 X 20.0-23.6) micron; shape index 1.1 (1.0-1.2). A micropyle and oocyst residuum are absent; polar granule present. Sporocysts are ovoid, 12.2 X 9.4 (11.2-12.8 X 8.4-10.0) micron, with Stieda and substieda bodies; shape index 1.3 (1.2-1.4). A sporocyst residuum is present, either compact, 5.1 X 4.2 (4.0-7.2 X 3.2-5.6) micron or diffuse. Sporozoites are elongate, with anterior and posterior refractile bodies. Isospora gekkonis was found in two of six (33%) P. m. grandis and one of five (20%) P. laticauda. In addition, oocysts of Cryptosporidium sp. were found in the cloacas of two of six (33%) necropsied P. m. grandis.     

Environmentally-induced shifts in behavior intensify indirect competition by an invasive gecko in Mauritius

Most recorded extinctions have occurred on oceanic islands, mainly as a result of introduced mammalian predators. The impact of introduced non-mammalian competitors, however, is poorly understood. The house gecko, Hemidactylus frenatus, is one of the most successful invasive reptiles and has been implicated in the decline of endemic geckos and other taxa on a number of tropical and subtropical islands. We investigated the patterns of niche utilization between the house gecko and endemic ornate day gecko, Phelsuma ornata, in Mauritius, two species which were not believed to compete because they had different diel activity periods. The dietary and temporal niche partitioning of the two species were examined in relation to seasonal invertebrate prey abundance for three seasons. Dietary overlap between the two species was least when prey abundance was lowest and temporal overlap in activity greatest. Exploitative competition was therefore inferred, whereby changes in dietary overlap were attributed to shifts in prey selection by the day, but not the house, gecko, which was hypothesized to deplete prey. The compensatory response of the day gecko may have been to increase its tendency for cannibalism, such that the smaller house gecko was indirectly responsible for population reduction of its larger competitor. This is the first study to show how an invasive nocturnal gecko may be affecting a predominantly diurnal species.     

Reconstructing an island radiation using ancient and recent DNA: the extinct and living day geckos (Phelsuma) of the Mascarene islands

Mitochondrial (12SrRNA and cyt b, 1086 bp) and nuclear (c-mos, 374 bp) DNA sequences were used to investigate relationships and biogeography of 24 living and extinct taxa of Phelsuma geckos. Monophyly of Phelsuma and sister relationship to the SW African Rhoptropella is corroborated. Phelsuma originated on Madagascar and made multiple long-distance invasions of oceanic islands including the Mascarenes, Aldabra, Comores, Seychelles, Andamans, and perhaps Pemba. The Mascarenes were probably colonised once, about 4.2-5.1Ma, and here Phelsuma rosagularis and Phelsuma inexpectata are newly recognised as species, as are three lineages of Phelsuma cepediana. Mascarene relationships are: Phelsuma edwardnewtoni, Phelsuma gigas (Phelsuma guentheri ((((P. cepediana A (P. cepediana B, C)) P. rosagularis) Phelsuma borbonica) ((Phelsuma ornata, P. inexpectata) Phelsuma guimbeaui))). The two recently extinct species, P. edwardnewtoni and the giant secondarily nocturnal Phelsuma gigas, differentiated on Rodrigues while on Mauritius the large nocturnal P. guentheri separated from a small diurnal form that radiated into six species, a likely result of volcanic activity. Two small-bodied lineages from Mauritius invaded the more recent island of Réunion producing two more species. Outside the Mascarenes, two mainly Madagascan assemblages are substantiated: Phelsuma serraticauda (Phelsuma lineata, Phelsuma laticauda, Phelsuma quadriocellata); (Phelsuma m. kochi (Phelsuma m. grandis, Phelsuma abboti)) (Phelsuma astriata, Phelsuma sundbergi). Their relationships to the Mascarene clade, and to Phelsuma mutabilis, Phelsuma standingi and Phelsuma andamanensis are unresolved.     

Coccidia (Protozoa: Eimeriidae) of the Alpaca Lama pacos*

SYNOPSIS. Three new species of coccidia are described from the alpaca Lama pacos from Peru. These are the first species of coccidia to be named from this host. The oocysts of Eimeria lamae n. sp. are ellipsoidal, occasionally ovoid, 30–40 by 21–30 μ (mean 35.6 by 24.5 μ) with elongate ovoid sporocysts 13–16 by 8–10 μ (mean 15.3 by 8.5 μ). The oocysts of Eimeria alpacae n. sp. are ellipsoidal, rarely ovoid, 22–26 by 18–21 μ (mean 24.1 by 19.6 μ), with ovoid sporocysts 10–13 by 7–8 μ (mean 11.0 by 6.8 μ). The oocysts of Eimeria punoensis n. sp. are ellipsoidal, occasionally ovoid, 17–22 by 14–18 μ (mean 19.9 by 16.4 μ), with ovoid sporocysts 8–11 by 5–7 μ (mean 9.2 by 6.1 μ).     

Multivariate phenotypic evolution among island and mainland populations of the ornate day gecko, Phelsuma ornata

Interpopulation variation in morphology, such as that among small island populations, plays a key role in speciation and diversification. There are two approaches to investigating evolution of morphological characters: comparing patterns of trait variances and covariances within and among populations, and testing particular adaptive scenarios. Here, we combine both approaches to infer the role of natural selection in shaping morphological variation in body size, head color pattern, and body shape among 10 populations of a day gecko, Phelsuma ornata, and its close relative, P. inexpectata, in the Mascarene Islands. We find that local populations are morphologically distinct, and that natural selection has likely influenced phenotypic diversification in the group. Lizards on small outer islands tend to be larger than lizards on the mainland of Mauritius. For body shape and head color pattern, comparisons of variation within and among populations reveal that differences among populations for some variables are too great to be explained by neutral processes alone, although we cannot identify the causal agents for this selection. These results reveal that the forces shaping different sets of organismal traits may be distinct, such that a variety of statistical approaches are needed to investigate selection in natural populations.     

Coccidia (Protozoa: Eimeridae) of the Herbivorous Mole-Rat, Spalax leucodon Nordmann

SYNOPSIS. A survey of 96 herbivorous mole-rats, Spalax leucodon Nordmann, in Lalahan district of Ankara, Turkey, revealed the presence of 6 new species of coccidia. The species found, the shape and average length-width dimensions (in micrometers) of their oocysts, and the numbers of animals from which they were isolated were as follow: Eimeria lalahanensis sp. n., subspherical to ellipsoidal (20.3 × 12.5), from 10; Eimeria tuzdili sp. n., spherical to subspherical with radially striated oocyst wall, (20.5 × 16.5), from 3; Eimeria spalacis sp. n., ellipsoidal to cylindrical (16.3 × 9.8), from 90; Eimeria elliptica sp. n., ellipsoidal (14.3 × 10.1), from 8; Eimeria turkmenica sp. n., ellipsoidal (11.3 × 8.9), from 1; Isospora anatolicum sp. n., spherical (7.6 × 5.1), from 1 animal. The overall infection rate for 96 examined herbivorous mole-rats was 100%.     

A Model for Taxonomic Work on Homoxenous Coccidia: Redescription, Host Specificity, and Molecular Phylogeny of Eimeria ranae Dobell, 1909, with a Review of Anuran-Host Eimeria (Apicomplexa: Eimeriorina)

ABSTRACT. We attempt to extend knowledge of anuran Eimeria , and to provide a model for a complex approach to studies on coccidia. New host and geographic records of coccidia in European Anura are provided. In the second part, Eimeria ranae Dobell, 1909 is redescribed from European terrestrial frogs of the genus Rana based on light microscopic and ultrastructural data on both exogenous and endogenous developmental stages, host specificity, and molecular phylogenetic data. Results of experimental transmissions show for the first time that the host specificity of E. ranae is restricted to the genus Rana and that isolates from tadpoles and adults are conspecific. Disappearance of infection during metamorphosis was confirmed experimentally, suggesting that infections in adults result from reinfections. Poikilotherm-host Eimeria species possessing a Stieda body (SB) are for the first time included in a molecular phylogenetic analysis. Eimeria ranae and Eimeria arnyi from a colubrid snake form together a well-supported clade, basal to other SB-bearing coccidia. The other analysed reptile–host eimerians, Eimeria tropidura and Choleoeimeria sp., which possess bivalved sporocysts and lack a SB, represent a distinct basal lineage of the eimeriid clade. The third part of the article reviews anuran-host Eimeria . Three distinct oocyst morphotypes, apparently correlating with the character of endogenous development, are recognized and characterized among anuran eimeriids.     

A partial systematic revision of the day geckos, Phelsuma Gray, of Madagascar (Reptilia: Squamata: Gekkonidae)

Recent survey work in Madagascar has led to significant changes in the systematics of Madagascan Phelsuma. A new species from the Masoala Peninsula in northeastern Madagascar is described, which has a nostril position typical of Phelsuma from Mauritius, Reunion and Rodriguez islands. Phelsuma breviceps was rediscovered in extreme southern Madagascar and is resurrected from the synonymy of P. mutabilis. Phelsuma breviceps has fragile skin, a probable predator escape mechanism, similar to the condition found in geckos of the genera Ailuronyx and Geckokpis. Three new synonyms are recognized. Phelsuma befotahensis and P. checki are junior synonyms of P. abbotti , and P. minuthi is a junior synonym of P. lineata. Twenty species of Phelsuma occur in Madagascar, of which 16 are endemic. A checklist and identification key are provided. Conservation problems of Phelsuma in the coastal regions of Madagascar are briefly discussed.     

Attempted Cross-Transmission of Coccidia Between Sheep and Goats and Description of Eimeria ovinoidalis sp. n.

SYNOPSIS.
Attempted infection of 2 young lambs with oocysts of Eimeria christenseni from a goat was unsuccessful. Negative results were obtained also when young kids were fed oocysts of Eimeria ninakohlyakimovae from sheep. There was no difficulty in infecting lambs with the sheep coccidium resembling E. ninakohlyakimovae nor goats with the goat coccidium E. christenseni. Oocysts from the goat measured 38.4 × 26.7 m, but were easily distinguished from Eimeria ahsata from the sheep by sporocyst size and shape, and from Eimeria ovina by oocyst size. Eimeria ninakohlyakimovae -like oocysts from sheep averaged 23.0 ×18.2 m and were morphologically indistinguishable from previously reported goat coccidia.
Since no cross infections of sheep and goats could be accomplished with oocysts of Eimeria sp. characteristic of one or the other host, I concluded that sheep coccidia previously known as E. ninakohlyakimovae are distinct from morphologically similar goat coccidia and therefore constitute a separate species. Since the name E. ninakohlyakimovae was first used for coccidia from the goat, the sheep coccidium is renamed Eimeria ovinoidalis with oocyst structure and endogenous stages similar to those previously described from the sheep.     

On the Parasitic Protozoa of Liberia. V. Coccidia of Liberian Rodents.

SYNOPSIS. In a survey of coccidia of rodents from Harbel, Libera, the following species of Eimeria were found and described: E. musculoidei n. sp. from Mus (Leggada) musculoides; E. separata Becker & Hall, 1931 from Rattus (Dephomys) defua (new host record); E. praomysis n. sp. from Rattus (Praomys) tullbergi rostratus; E. dasymysis n. sp. from Dasymys incomptus rufulus; E. lemniscomysis n. sp. from Lemniscomys striatus striatus; and E. lophuromysis n. sp., E. sikapusii n. sp., E. liberiensis n. sp., E. harbelensis n. sp., E. africana n. sp., and E. kruidenieri n. sp. from Lophuromys sikapusi sikapusi.     

Attempted cross-transmission of coccidia between sheep and goats and description of Eimeria ovinoidalis sp. n.

Attempted infection of 2 young lambs with oocysts of Eimeria christenseni from a goat was unsuccessful. Negative results were obtained also when young kids were fed oocysts of Eimeria ninakohlyakimovae from sheep. There was no difficulty in infecting lambs with the sheep coccidium resembling E. ninakohlyakimovae nor goats with the goat coccidium E. christenseni. Oocysts from the goat measured 38.4 X 26.7 microns, but were easily distinguished from Eimeria ahsata from the sheep by sporocyst size and shape, and from Eimeria ovina by oocyst size. Eimeria ninakohlyakimovae-like oocysts from sheep averaged 23.0 X 18.2 microns and were morphologically indistinguishable from previously reported goat coccidia. Since no cross infections of sheep and goats could be accomplished with oocysts of Eimeria sp. characteristic of one or the other host, I concluded that sheep coccidia previously known as E. ninakohlykimovae are distinct from morphologically similar goat coccidia and therefore constitute a separate species. Since the name E. ninakohlyakimovae was first used for coccidia from the goat, the sheep coccidium is renamed Eimeria ovinoidalis with oocyst structure and endogenous stages similar to those previously described from the sheep.     

Species of coccidia (Apicomplexa: Eimeriidae) in shrews from Alaska, U.S.A., and northeastern Siberia, Russia, with description of two new species

Fecal samples (n = 636) from 10 species of shrews collected in Alaska (n = 540) and northeastern Siberia (n = 96) were examined for the presence of coccidia (Apicomplexa: Eimeriidae). Five distinct oocyst morphotypes were observed. Three types were consistent with oocysts of previously recognized coccidia species from other shrew hosts. These were Eimeria inyoni, E. vagrantis, and Isospora brevicauda, originally described from the inyo shrew (Sorex tenellus), dusky shrew (S. monticolus), and northern short-tailed shrew (Blarina brevicauda), respectively. We found 5 new host records for E. inyoni, 3 for E. vagrantis, and 3 for I. brevicauda. The 2 additional oocyst morphotypes, both from the tundra shrew (Sorex tundrensis), are putative new species. Sporulated oocysts of Eimeria beringiacea n. sp. are subspheroidal, 17.7 x 15.6 microm (14-24 x 13-20 microm) with a length (L)/width (W) ratio of 1.1 (1.0-1.4); these lack a micropyle (M), an oocyst residuum (OR), and a polar granule (PG). Sporocysts are ellipsoidal, 10.3 x 6.1 microm (7-14 x 4-8 microm), with a L/W ratio of 1.7 (1.3-2.3) and have a Stieda body (SB), Substieda body (SSB), and sporocyst residuum (SR). Oocysts of Eimeria tundraensis n. sp. are spheroidal to subspheroidal, 24.8 x 23.5 microm (23-26 x 22-25 microm), with a L/W ratio of 1.1 (1.0-1.2); these lack a M and OR, but a single PG is present. Sporocysts are elongate ellipsoidal, 15.4 x 8.3 microm (13-17 x 7-9 microm), with a L/W ratio of 1.9 (1.4-2.1) and have a SB, SSB, and SR.     

Eimeria fraterculae sp. n. in the kidneys of Atlantic puffins (Fratercula arctica) from Newfoundland, Canada: species description and lesions

Renal coccidiosis is reported for the first time in an auk (Alcidae). Infection was detected in seven of 50 nestling Atlantic puffins (Fratercula arctica) and a new species of coccidia, Eimeria fraterculae sp. n., is described. The structure and sporulation of oocysts are characterized. Meronts, gamonts, and developing oocysts were present in collecting duct epithelium of medullary cones. The predominant host response was hypertrophy of infected cells, tubule dilation, and a mild localized peritubular infiltration with mononuclear inflammatory cells.     

Ecological Effects of the Invasive Giant Madagascar Day Gecko on Endemic Mauritian Geckos: Applications of Binomial-Mixture and Species Distribution Models

The invasion of the giant Madagascar day gecko Phelsuma grandis has increased the threats to the four endemic Mauritian day geckos (Phelsuma spp.) that have survived on mainland Mauritius. We had two main aims: (i) to predict the spatial distribution and overlap of P. grandis and the endemic geckos at a landscape level; and (ii) to investigate the effects of P. grandis on the abundance and risks of extinction of the endemic geckos at a local scale. An ensemble forecasting approach was used to predict the spatial distribution and overlap of P. grandis and the endemic geckos. We used hierarchical binomial mixture models and repeated visual estimate surveys to calculate the abundance of the endemic geckos in sites with and without P. grandis. The predicted range of each species varied from 85 km² to 376 km². Sixty percent of the predicted range of P. grandis overlapped with the combined predicted ranges of the four endemic geckos; 15% of the combined predicted ranges of the four endemic geckos overlapped with P. grandis. Levin''s niche breadth varied from 0.140 to 0.652 between P. grandis and the four endemic geckos. The abundance of endemic geckos was 89% lower in sites with P. grandis compared to sites without P. grandis, and the endemic geckos had been extirpated at four of ten sites we surveyed with P. grandis. Species Distribution Modelling, together with the breadth metrics, predicted that P. grandis can partly share the equivalent niche with endemic species and survive in a range of environmental conditions. We provide strong evidence that smaller endemic geckos are unlikely to survive in sympatry with P. grandis. This is a cause of concern in both Mauritius and other countries with endemic species of Phelsuma.     

Eimeria species (Apicomplexa: Eimeriidae) from arctic ground squirrels (Spermophilus parryii) and red squirrels (Tamiasciurus hudsonicus) in Alaska and in Siberia, Russia

Fecal samples from arctic ground squirrels (Spermophilus parryii) collected in Alaska (n = 90) and Russia (n = 46) and from red squirrels (Tamiasciurus hudsonicus) in Alaska (n = 35) were examined for the presence of Eimeria spp. (Apicomplexa: Eimeriidae). Four species were recovered from arctic ground squirrels, including Eimeria callospermophili (prevalence = 18%), Eimeria cynomysis (23.5%), Eimeria lateralis (19%), and Eimeria morainensis (77%). A single species, Eimeria tamiasciuri (91%), was recovered from red squirrels. Eimerians recovered from arctic ground squirrels represent new host records, and the single species from red squirrels is a new geographic record. Alaskan arctic ground squirrel prevalence was higher for E. callospermophili (Alaska = 22% vs. Russia = 9%), E. cynomysis (34% vs. 2%), and E. lateralis (27% vs. 4%), but not E. morainensis (78% vs. 76%).     

Intestinal coccidia of white-tailed deer in southern Florida

From 1984 to 1986 110 white-tailed deer (Odocoileus virginianus) from Big Cypress National Preserve in southern Florida were examined for intestinal coccidial infections. Three species of Eimeria (E. mccordocki, E. madisonensis, and E. odocoilei) were found in low prevalences. There were no differences in prevalence due to age, sex, season of collection or specific locality within the Preserve.     

A new endemic gecko (Reptilia: Gekkonidae) from Mauritius

A previously undescribed gecko, Nactus coindemirensis sp. nov. is reported from Gunner's Quoin, a small island off Mauritius. Nactus coindemirensis is not especially closely related to the other Mauritian member of the genus, N. serpensinsula; thus, it is likely that the precursors of these two species reached Mauritius separately, rather than both being descended from a single colonizer. Unlike other Mauritian reptiles now known only from small off-shore islands, N. coindemirensis coexists with rats, perhaps because it can evade them by taking refuge in small holes and crevices of the basalt it inhabits. This raises the possibility that it may still survive on other islands with rats, including Mauritius itself, but has escaped notice because of its size and cryptic behaviour.     

Spauligodon ovifilus n. sp. (Nematoda: Pharyngodonidae) and other helminths from Diplodactylus stenodactylus (Reptilia: Gekkonidae) from Australia

Spauligodon ovifilus n. sp. (Nematoda: Pharyngodonidae) from the large intestines of the gecko Diplodactylus stenodactylus is described and illustrated. Prevalence of infection was 50% (mean intensity 5.9 +/- 6.3, range 1-21). Spauligodon ovifilus n. sp. represents the thirty-fifth species to be assigned to this genus and is distinguished by the extremely long filament of the egg. This is the first report of species of Spauligodon from Australia. In addition, 1 gecko harbored 1 female of Wanaristrongylus papangawurpae, a new host record; 1 gecko harbored 1 encapsulated larva of Abbreviata sp. Review of species assigned to Spauligodon caused the reclassification of Spauligodon azerbajdzanicus to Skrjabinodon azerbajdzanicus n. comb.     

The ecology of lizards on Praslin Island, Seychelles

Ecological studies of five species of lizards were carried out on the island of Praslin, central Seychelles between July and September 1976. Quadrat sampling within four vegetation types revealed distinct habitat preferences between species. Phelsuma sundbergi occurred at highest densities in coastal vegetation, particularly coconuts Cocos nucifera , whilst Phelsuma astriata occurred at highest densities in intermediate forest, particularly in endemic palms such as Lodoicea maldivica. Within each vegetation type, both species preferred particular tree species. In coastal coconuts and Lodoicea in intermediate forest, the two species tended to occur in different sized trees. Calculations of niche breadth indicated greatest values for P. sundbergi in coastal vegetation and for P. astriata in intermediate forest. Both Phelsuma species showed a diurnal pattern of activity with some indication of temporal displacement between species in lowland and intermediate forest. Ailuronyx sechellensis was nocturnal with a relict distribution on Praslin, occurring in the quadrats on only three endemic palm species in intermediate forest. Mabuya sechellensis was by far the commonest and most widespread of the two skink species, with highest density in intermediate forest where it was probably favoured by the high proportion of palm leaf litter. Scelotes gardineri was only recorded in lowland and intermediate forest, where it occurred at low densities. Both species were diurnal, although the latter was never recorded after midday. Intermediate forest had the highest lizard biomass and species diversity whilst eroded land had the lowest. The possible origins and relationships of the two closely related Phelsuma species are discussed, together with the roles that habitat modification, predation, and interspecific competition may play.