scholarly journals The drivers and functions of rock juggling in otters

2020 ◽  
Vol 7 (5) ◽  
pp. 200141 ◽  
Author(s):  
Mari-Lisa Allison ◽  
Rebecca Reed ◽  
Emile Michels ◽  
Neeltje J. Boogert

Object play refers to the seemingly non-functional manipulation of inanimate items when in a relaxed state. In juveniles, object play may help develop skills to aid survival. However, why adults show object play remains poorly understood. We studied potential drivers and functions of the well-known object play behaviour of rock juggling in Asian small-clawed ( Aonyx cinereus ) and smooth-coated ( Lutrogale perspicillata ) otters. These are closely related species, but Asian small-clawed otters perform extractive foraging movements to exploit crabs and shellfish while smooth-coated otters forage on fish. We thus predicted that frequent rock jugglers might be better at solving extractive foraging puzzles in the first species, but not the latter. We also assessed whether species, age, sex and hunger correlated with rock juggling frequency. We found that juvenile and senior otters juggled more than adults. However, rock juggling frequency did not differ between species or sexes. Otters juggled more when ‘hungry’, but frequent jugglers did not solve food puzzles faster. Our results suggest that rock juggling may be a misdirected behaviour when hungry and may facilitate juveniles' motor development, but it appears unrelated to foraging skills. We suggest future studies to reveal the ontogeny, evolution and welfare implications of this object play behaviour.

Phytotaxa ◽  
2019 ◽  
Vol 424 (3) ◽  
pp. 147-157 ◽  
Author(s):  
CORINNA ROMEIKAT ◽  
ALEJANDRO IZQUIERDO LÓPEZ ◽  
CHRISTINE TIETZE ◽  
JULIANE KRETSCHMANN ◽  
MARC GOTTSCHLING

The application of scientific names is determined by means of nomenclatural types, and every name has to be typified properly. The concept has limitations for unicellular organisms, because original material frequently consists of drawings and/or inadequately preserved physical material. Peridinium cinctum is an abundant freshwater microalga and variable in both morphology and genotype. Morphological variation is mainly expressed in its epithecal conformation: shape deviations of plates, plate rearrangements, plate fusion and plate additions. Different epithecal conformations were traditionally described as either varieties of P. cinctum or were established as closely related species. Despite this, relations between varieties, ribotypes and geographic locations were oversighted, and the full spectrum of plate variation in P. cinctum is still not well represented. For this reason, we sampled localities in Germany and Poland, from which varieties of P. cinctum were described a century ago. We cultivated monoclonal strains, exhibiting two distinct ITS ribotypes, and assessed their epithecal variation of morphology. Based on ca 2,500 observations of individual cells we report a plethora of both plate and suture deviations from the archetypical epithecal conformation of P. cinctum. Morphologies corresponding to previously described varieties were rare, even at their type localities. Nevertheless, we found morphologies consistent with protologues in four cases and use this material for epitypification. These varieties are now linked to specific DNA sequences, allowing reliable application of scientific names for future studies.


Behaviour ◽  
2016 ◽  
Vol 153 (6-7) ◽  
pp. 845-869 ◽  
Author(s):  
Charmalie A.D. Nahallage ◽  
Jean-Baptiste Leca ◽  
Michael A. Huffman

Object play in primates is viewed as generally having no immediate functional purpose, limited for the most part to immature individuals. At the proximate level, the occurrence of object play in immatures is regarded as being intrinsically self-rewarding, with the ultimate function of supporting motoneuronal development and the acquisition of skills necessary to prepare them for survival as adults. Stone handling (SH), a solitary object play behaviour occurs, and has been studied, in multiple free-ranging and captive troops of provisioned Japanese macaques, as well as rhesus and long-tailed macaques for over 35 years now. A review of our combined findings from these observations reveal that infants acquire SH in the first 3-4 months of life and exhibit increasingly more complex and varied behavioural patterns with age. The longitudinal data shows that many individuals maintain this activity throughout life, practicing it under relaxed ecological and social conditions. The ultimate function may be bimodal, promoting motor development in young and neural maintenance and regeneration in adult and aging individuals.


2020 ◽  
Vol 9 (3) ◽  
pp. 160-170
Author(s):  
Thumadath P.A. Krishna ◽  
Maharajan Theivanayagam ◽  
Gurusunathan V. Roch ◽  
Veeramuthu Duraipandiyan ◽  
Savarimuthu Ignacimuthu

Finger millet is a superior staple food for human beings. Microsatellite or Simple Sequence Repeat (SSR) marker is a powerful tool for genetic mapping, diversity analysis and plant breeding. In finger millet, microsatellites show a higher level of polymorphism than other molecular marker systems. The identification and development of microsatellite markers are extremely expensive and time-consuming. Only less than 50% of SSR markers have been developed from microsatellite sequences for finger millet. Therefore, it is important to transfer SSR markers developed for related species/genus to finger millet. Cross-genome transferability is the easiest and cheapest method to develop SSR markers. Many comparative mapping studies using microsatellite markers clearly revealed the presence of synteny within the genomes of closely related species/ genus. Sufficient homology exists among several crop plant genomes in the sequences flanking the SSR loci. Thus, the SSR markers are beneficial to amplify the target regions in the finger millet genome. Many SSR markers were used for the analysis of cross-genome amplification in various plants such as Setaria italica, Pennisetum glaucum, Oryza sativa, Triticum aestivum, Zea mays and Hordeum vulgare. However, there is very little information available about cross-genome amplification of these markers in finger millet. The only limited report is available for the utilization of cross-genome amplified microsatellite markers in genetic analysis, gene mapping and other applications in finger millet. This review highlights the importance and implication of microsatellite markers such as genomic SSR (gSSR) and Expressed Sequence Tag (EST)-SSR in cross-genome analysis in finger millet. Nowadays, crop improvement has been one of the major priority areas of research in agriculture. The genome assisted breeding and genetic engineering plays a very crucial role in enhancing crop productivity. The rapid advance in molecular marker technology is helpful for crop improvement. Therefore, this review will be very helpful to the researchers for understanding the importance and implication of SSR markers in closely related species.


Genetics ◽  
2004 ◽  
Vol 166 (2) ◽  
pp. 789-796 ◽  
Author(s):  
Kyoichi Sawamura ◽  
John Roote ◽  
Chung-I Wu ◽  
Masa-Toshi Yamamoto

Abstract Recent genetic analyses of closely related species of Drosophila have indicated that hybrid male sterility is the consequence of highly complex synergistic effects among multiple genes, both conspecific and heterospecific. On the contrary, much evidence suggests the presence of major genes causing hybrid female sterility and inviability in the less-related species, D. melanogaster and D. simulans. Does this contrast reflect the genetic distance between species? Or, generally, is the genetic basis of hybrid male sterility more complex than that of hybrid female sterility and inviability? To clarify this point, the D. simulans introgression of the cytological region 34D-36A to the D. melanogaster genome, which causes recessive male sterility, was dissected by recombination, deficiency, and complementation mapping. The 450-kb region between two genes, Suppressor of Hairless and snail, exhibited a strong effect on the sterility. Males are (semi-)sterile if this region of the introgression is made homozygous or hemizygous. But no genes in the region singly cause the sterility; this region has at least two genes, which in combination result in male sterility. Further, the males are less fertile when heterozygous with a larger introgression, which suggests that dominant modifiers enhance the effects of recessive genes of male sterility. Such an epistatic view, even in the less-related species, suggests that the genetic complexity is special to hybrid male sterility.


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