SciCombinator

Discover the most talked about and latest scientific content & concepts.

Journal: Integrative zoology

27

A lion-like pantherine felid is described as Panthera (Leo) fossilis (von Reichenau, 1906) from the late Early Pleistocene sediments of the Kuznezk Basin (Western Siberia, Russia). The find of P. fossilis first recorded in Asia considerably extends current notion of the eastward expansion of the most ancient lions. The Siberian lion is geologically the oldest form and is dimensionally among the largest members of the group of fossil lions on the Eurasian continent. Although known by mandibular remains only, it is readily distinguished from Panthera (Leo) spelaea (Goldfuss, 1810) by a heavy built mandibular corpus with rectangular profile in the cheek teeth area, a deep, well-outlined and narrow anterior section of the masseteric fossa, and a large р4 supported by a big unreduced anterior root. These features the Siberian lion shares with the European Middle Pleistocene P. fossilis and American Late Pleistocene P. (Leo) atrox (Leidy, 1853), which suggests their close relationship. P. atrox originated from P. fossilis and was isolated in North America south of the Late Pleistocene ice sheets. This explains why the American lion has retained more primitive features than the coeval Eurasian cave lion P. (L.) spelaea. This article is protected by copyright. All rights reserved.

Concepts: Asia, Lion, Felidae, Russia, Pleistocene, Panthera, Jaguar, Lions

25

Curious eroded depressions, most resembling an eye shedding an elongate tear, are found in gently sloping, intertidal, carbonate-rich arenite outcropping on the sea coast near Lakes Entrance, Victoria, SE Australia. The depressions, known locally as “Tears of the Virgin”, are evidently formed by multiple generations of a barnacle, Chthamalus antennatus Darwin, 1854 in association with cyanobacteria.  While the round part of a depression offers the barnacle a modicum of protection from impacts during high tides, it is also partially inhabited by cyanobacteria, which extend into and tend to fill the elongate tear. As such, this appears to be the first case of mutualism between a higher invertebrate and cyanobacteria; the cyanobacteria reducing the barnacle’s risk of desiccation while receiving metabolic wastes from it during low tides.  It is also the first record of a balanomorph barnacle eroding calcareous arenite beneath its shell, the net effect of which would be expected to reduce its adhesion to the substrate.  However the siliceous residue, resulting from the barnacle’s dissolution of the more than 80% of the calcite-rich sedimentary rock, is sequestered in delicate folds on the inside of the shell wall as it grows.  A brief review of cirripedes capable of excavation includes the first photographic documentation of excavation of a mollusc shell by a verrucomorph. This article is protected by copyright. All rights reserved.

Concepts: Arthropod, Sediment, Fossil, Copyright, Intertidal zone, Tide, Barnacle, Barnacles

25

In order to conserve and culture the cichlid fish Archocentrus nigrofasciatus, more information about its reproductive biology and its larval behaviour and morphogenesis is necessary. Currently, temperatures ranging from 21°C to 27°C are used in ornamental aquaculture hatcheries. Lower temperatures are preferred in order to reduce the costs for water heating and 23°C is usually the selected temperature. However, there is limited information on culturing protocols for ornamental species and most of the information generated remains scarce. Thus, this study examines the morphological development of A. nigrofasciatus during the yolk sac period until the age of 100 hours post-hatching in relation to two temperature regimes used in ornamental aquaculture: a temperature of 27°C (thermal optimum) and a decreased temperature of 23°C (thermal tolerance). The results of this study suggest that the 27°C temperature generates intense morphological changes in yolk-sac development in a shorter period. This has advantages as it reduces the time of yolk-sac larval development, thus, minimizes the transition phase to exogenous feeding and maximizes the efficiency at which yolk is converted into body tissues. This paper provides necessary information to produce freshwater ornamental fish with better practices so as to increase larval survival and capitalize on time for growth. This article is protected by copyright. All rights reserved.

Concepts: Cichlid, Fish, Heat, Tilapia, Copyright, Yolk sac, Convict cichlid, Archocentrus

24

The ballan wrasse, Labrus bergylta is a marine fish belonging to the family Labridae characterised by two main morphotypes that occur in sympatry: spotty and plain. Previous studies have revealed differences in their life-history traits such as growth and maturation; however, the genetic relationship between forms is presently unknown. Using twenty recently developed microsatellite markers, we conducted a genetic analysis of 41 and 48 spotty and plain ballan wrasse collected in Galicia (NW Spain). The two morphotypes displayed highly significant genetic differences to each other (FST = 0.018, P<0.0001). A similar degree of genetic differentiation (FST = 0.025, P<0.0001) was shown using STRUCTURE clustering approach with no priors at K = 2. In this case, the frequency of spotty and plain morphotypes was significantly different (x(2) = 9.46, P = 0.002). It is concluded that there is significant genetic heterogeneity within this species, which appears to be highly associated with the spotty and plain forms, but not completely explained by them. Given the previously demonstrated biological differences between morphotypes, and the present genetic analyses, we speculate about the convenience of a taxonomic re-evaluation of this species. This article is protected by copyright. All rights reserved.

Concepts: Present, Biology, All rights reserved, Copyright, Labridae, Wrasse, Labrus, Ballan wrasse

24

Species of the genus Gynandropaa within the family Dicroglossidae are typical spiny frogs whose taxonomic status has long been in doubt. We used integrative methods, involving morphological and molecular analyses, to elucidate the phylogenetic relationships, and determine identities and geographic distribution of each valid species. We obtained DNA sequence data of five species of Gynandropaa (complete sequences of the mitochondrial ND2 gene, and 890 bp of 12S rRNA and 16S rRNA partial sequences) from 37 localities (including the topotypes of five described species) and constructed Bayesian and Maximum-likelihood trees to examine phylogeography. Twenty eight morphological variables were taken on 624 specimens. Three clades with clear geographic patterns were recognized: clade C (from southwestern Sichuan Province and Central Yunnan Province), clade E (western Guizhou Province and eastern to central Yunnan Province), and clade W (western to southern Yunnan Province). Integrating morphological characteristics and distribution information, the clades W, E and C represent G. yunnanensis, G. phrynoides and G. sichuanensis respectively. Based on these, we draw the conclusions: 1) the validity of G. phrynoides should be rehabilitated; 2) G. liui is a junior synonym of G. sichuanensis; 3) G. yunnanensis is a valid species while G. bourreti is probably a subspecies of G. yunnanensis with the distribution range from Vietnam to southern Yunnan Province. This study should help to clear up the taxonomic status of Gynandropaa and give important information for understanding the evolution and conservation of these spiny frogs. This article is protected by copyright. All rights reserved.

Concepts: DNA, Species, Phylogenetics, Yunnan, Sichuan, Guizhou, Yi people, Autonomous prefectures of China

6

Telemetry studies that track animals through space and time can lead to advances in scientific understanding that are vital in conservation efforts. For example, telemetry studies of the giant panda (Ailuropoda melanoleuca) have shed light on many aspects of panda biology, but small sample sizes in each separate study make it difficult to draw broad conclusions. To overcome this problem we conducted the first synthesis of all five panda telemetry studies conducted to date. Using these data we investigated patterns in 6 main topics - home range, space-use interactions, core areas, movement patterns, seasonal migration, and natal dispersal. We found that panda home range sizes do not vary between two main mountain ranges (Qionglai and Qinling), as was previously thought. Our results also suggest that females increase their movement in the mating season - a behavior typically attributed to only males. We found and summarized widespread telemetry and genetic evidence for female natal dispersal in the giant panda. Our synthesis highlights the need for additional research relating panda behavior to human disturbance factors, and can aid future studies on giant pandas as well as other species. This article is protected by copyright. All rights reserved.

Concepts: Giant Panda, Carnivora, Bear, Ailuropoda, Qinling Panda, Red Panda, Memphis Zoo, Qinling Mountains

3

The means of orientation is studied in the Vietnamese pygmy dormouse Typhlomys chapensis, a poorly known enigmatic semi-fossorial semi-arboreal rodent. Data on eye structure are presented, which prove that Typhlomys (translated as “the blind mouse”) is incapable of object vision - the retina is folded and retains no more than 2 500 ganglion cells in the focal plane, and the optic nerve is subject to gliosis. Hence, Typhlomys has no other means for rapid long-range orientation among tree branches other than echolocation. Ultrasonic vocalization recordings at the frequency range of 50-100 kHz support this hypothesis. The vocalizations are represented by bouts of up to 7 more or less evenly-spaced and uniform frequency-modulated sweep-like pulses in rapid succession. Structurally, these sweeps are similar to frequency-modulated ultrasonic echolocation calls of some bat species, but they are too faint to be revealed with a common bat detector. When recording video simultaneously with the ultrasonic audio, a significantly greater pulse rate during locomotion compared to that of resting animals has been demonstrated. Our findings of locomotion-associated ultrasonic vocalization in a fast-climbing but weakly-sighted small mammal ecotype add support to the “echolocation-first theory” of pre-flight origin of echolocation in bats. This article is protected by copyright. All rights reserved.

Concepts: Retina, Mammal, Ultrasound, Frequency, Rodent, Bat, Copyright, Microbat

1

The genus Ochotona (pikas) is a clade of cold-tolerant lagomorphs that includes many high-elevation species. Pikas offer a unique opportunity to study adaptations and potential limitations of an ecologically important mammal to high-elevation hypoxia. We analyzed the evolution of three mitochondrial genes encoding the catalytic core of cytochrome c oxidase (COX) in 10 pika species occupying elevations from sea level to 5,000 meters. COX is an enzyme highly reliant on oxygen and essential for cell function. One amino acid property, the equilibrium constant (ionization of COOH), was found to be under selection in the overall protein complex. We observed a strong relationship between the net value change in this property and the elevation each species occupies, with higher-elevation species having potentially more efficient proteins. We also found evidence of selection in low-elevation species for potentially less efficient COX, perhaps trading efficiency for heat production in the absence of hypoxia. Our results suggest that different pika species may have evolved elevation-specific COX proteins, specialization that may indicate limitations in their ability to shift their elevational ranges in response to future climate change. This article is protected by copyright. All rights reserved.

1

Inference by exclusion is the ability to select a given option by excluding the others. When designed appropriately, tests of this ability can reveal choices that cannot be explained by associative processes. Over the past decade, exclusion reasoning has been explored in several non-human taxonomic groups including birds, mainly in Corvids and Parrots. To increase our understanding of the taxonomic distribution of exclusion reasoning and therefore its evolution, we investigated exclusion performances in Red-tailed Black cockatoos (Calyptorhynchus banksii), an Australian relative of the Goffin cockatoo (Cacatua goffinia), using a food-finding task. Cockatoos were required to find a food item hidden in one of the two experimenter’s hands. Following training sessions in which they reliably selected the closed baited hand they had just been shown open, each individual was tested on four different conditions. Critical to demonstrating exclusion reasoning was the condition in which they were shown the empty hand and then offered a choice of both closed hands. The performance of all birds was above chance on all experimental conditions but not on an olfactory and/or cuing control condition. The results suggest that the birds might be able to infer by exclusion, although an explanation based on rule learning cannot be excluded. This first experiment in Red-tailed Black cockatoo highlights this species' potential as a model to study avian cognition and paves the pathway for future investigations.

Concepts: Reasoning, Parrot, Cockatoo, Cacatua, Tanimbar Corella, Red-tailed Black Cockatoo, Glossy Black Cockatoo, Calyptorhynchus

1

Bitter taste receptor genes (TAS2Rs) mediate bitterness perception in mammals. It is believed that these genes evolved in response to species-specific diets. The giant panda (Ailuropoda melanoleuca) and red panda (Ailurus fulgens styani) in the order Carnivora are specialized herbivores with an almost exclusive bamboo diet (>90% bamboo). Because bamboo is full of bitter tasting compounds, we hypothesized that adaptive evolution have occurred at TAS2R genes in giant and red pandas throughout the course of their dietary shift. Here, we characterized 195 TAS2Rs in nine Carnivora species and examined selective pressures on these genes. We found that both pandas harbour more putative functional TAS2Rs than other carnivores, and pseudogenized TAS2Rs in the giant panda are different from the red panda. The purifying selection on TAS2R1, TAS2R9 and TAS2R38 in the giant panda, and TAS2R62 in the red panda, has been strengthened throughout the course of adaptation to bamboo diet, while selective constraint on TAS2R4 and TAS2R38 in the red panda is relaxed. Remarkably, a few positively selected sites has been lineage-specifically detected on TAS2R42 in the giant panda. These results suggest an adaptive response in both pandas to a dietary shift from carnivory to herbivory, and TAS2Rs evolved independently in the two pandas. Our findings provide new insights into the molecular basis of mammalian sensory evolution and the process of adaptation to new ecological niches. This article is protected by copyright. All rights reserved.

Concepts: Natural selection, Giant Panda, Carnivora, Ailuridae, Red Panda, Bamboo, Procyonidae