Mother–embryo isotope fractionation in the pygmy devilray Mobula kuhlii cf. eregoodootenkee

We determined stable-isotope ratios for replicate muscle tissues in 13 gravid Mobula kuhlii cf. eregoodootenkee (110.4–120.4 cm disc width; W_D) and their embryos (7.0–42.3 cm W_D) and also yolks and histrotroph, to assess the potential implications for juvenile nutrition and habitat use. Irrespective of their development in the uterus, embryos had similar δ¹³C values in their muscle tissue as the mothers and both had greater values than in the histotroph. During gestation, δ¹³C values increased across all sample types. However, while embryo muscle tissue and the histotroph were associated with increasing ¹⁵N levels during embryonic development, this was depleted in the mothers’ muscle tissue and yolk. Although speculative, the observed variation in stable-isotope ratios might imply a dietary shift among gravid females during their early gestation. Irrespective of the underlying mechanisms, the results indicate neonates will have relatively greater δ¹⁵N values than post-partum females, which would probably confound juvenile foraging-ecology estimates.     

A morphological,molecular, and histopathological redescription of Henneguya nyongensis Fomena & Bouix, 1996 (Cnidaria: Myxobolidae) infecting the gills of Peter’s elephantnose fish,Gnathonemus petersii (Günther) (Osteoglossiformes: Mormyridae), imported from Nigeria

Systematic Parasitology - A Henneguya sp., morphologically resembling Henneguya nyongensis Fomena & Bouix, 1996, was isolated from the gills of Peter’s elephantnose fish, Gnathonemus...     

Effects of congested match periods on acceleration and deceleration profiles in professional soccer

The aim of the present study was to analyse the influence of congested periods of matches on the acceleration (Acc) and deceleration (Dec) profiles of elite soccer players. Twenty-three elite male professional soccer players participated in the study across 31 official matches. Assessed periods included: (i) congested periods (three to four days between games), and (ii) non-congested periods (more than four days between games). Physical activity during matches was recorded during games using a 10Hz global positioning system device, coupled with a 100 Hz accelerometer, and was analysed according to the periods. Maximal Acc- (73.2 ± 20.3 vs. 84.918.5 m), high Acc- (244.0 ± 49.5 vs. 267.0 ± 37.8 m), maximal Dec- (139.0 ± 44.8 vs. 152.039.3 m) and the total decelerating- distance (5132 ± 690 vs. 5245 ± 552 m) were lower in congested than in non-congested periods (p < 0.05, effect size 0.31–0.70). Neither a main effect of playing position nor a period*playing position interaction on Acc and Dec were observed (p > 0.05). It was concluded that Acc and Dec match activities were significantly affected during congested periods compared to non-congested highlighting a possible fatigue accumulation being responsible for the observed decrement in physical activity. Monitoring Acc and Dec metrics throughout particular periods of congested fixtures amongst professional soccer teams is advised and may be a way to assess physical and fatigue status.     

The role of novelty and fat and sugar concentration in food selection by captive tufted capuchins (Sapajus apella)

Capuchins, like other primates, use feedback from sensory cues and digestion to make decisions about which foods to consume and which to avoid. However, little is known about how capuchins make consumption decisions when simultaneously presented with novel and familiar foods, or how food familiarity and macronutrient concentration together influence food choice, topics with potential implications for developmental and health research. In this study, we evaluated the role of familiarity, as well as fat and sugar concentration, in the food selections of captive tufted capuchins (Sapajus apella). In the first experiment, over 10 sessions, subjects were assigned to either a group that chose between one familiar and one novel food item both high in fat or sugar (high condition), or to a group that chose between one familiar and one novel food item both low in fat or sugar (low condition). In the second experiment, subjects were divided into three groups, familiarized with food over five feeding sessions, and then offered the familiarized food and a novel food that varied in fat or sugar for 10 sessions. When offered foods high in fat, capuchins showed no clear signs of neophobia, forming an initial preference for the novel food, rejecting foods less frequently, and selecting foods faster than when offered foods low in fat. These trends were generally not observed in response to foods with sugar. When presented with options that varied in macronutrient concentration, subjects showed an initial interest in the novel food irrespective of whether it was high in fat or sugar, yet formed a final preference for the higher-concentration item. Findings suggest that the concentration of fat or sugar in novel foods may be an important mediator of exploratory behavior and that capuchins rely on immediate feedback from taste and other sensory cues to make consumption decisions.     

Pseudanthocotyloides heterocotyle (van Beneden, 1871) Euzet & Prost, 1969 (Monogenea: Polyopisthocotylea: Mazocraeidae), a parasite of herring Clupea harengus L. and sprat Sprattus sprattus L. (Teleostei: Clupeidae)

A total of 690 herring Clupea harengus L. and 88 sprat Sprattus sprattus L. caught off the west coast of Sweden, in the North Sea and off the west and south coasts of the United Kingdom, were examined for gill parasites. The monogenean Pseudanthocotyloides heterocotyle (van Beneden, 1871) Euzet & Prost, 1969 was found in 38 (5.5%) herring and one (1.1%) sprat. The parasite was significantly (P>0.05) more common off the west coast of Sweden than elsewhere and most specimens (62.5%) were found on the pseudobranchs. Only the smaller herring were infected. P. heterocotyle is redescribed and its taxonomy discussed, together with the possibility of host and parasite misidentification in previous reports.