• Molecular changes in skin pigmented lesions of the coral trout Plectropomus leopardus.

      Lerebours, Adélaïde; Chapman, Emma C.; Sweet, Michael J.; Heupel, Michelle R.; Rotchell, Jeanette M.; University of Hull; University of Derby; Australian Institute of Marine Science; James Cook University (Elsevier, 2016-07-28)
      A high prevalence of skin pigmented lesions of 15% was recently reported in coral trout Plectropomus leopardus, a commercially important marine fish, inhabiting the Great Barrier Reef. Herein, fish were sampled at two offshore sites, characterised by high and low lesion prevalence. A transcriptomic approach using the suppressive subtractive hybridisation (SSH) method was used to analyse the differentially expressed genes between lesion and normal skin samples. Transcriptional changes of 14 genes were observed in lesion samples relative to normal skin samples. These targeted genes encoded for specific proteins which are involved in general cell function but also in different stages disrupted during the tumourigenesis process of other organisms, such as cell cycling, cell proliferation, skeletal organisation and cell migration. The results highlight transcripts that are associated with the lesion occurrence, contributing to a better understanding of the molecular aetiology of this coral trout skin disease.
    • Variation in size frequency distribution of coral populations under different fishing pressures in two contrasting locations in the Indian Ocean

      Grimsditch, Gabriel; Pisapia, Chiara; Huck, Maren; Karisa, Juliet; Obura, David; Sweet, Michael J.; International Union for the Conservation of Nature; James Cook University; University of Derby; Kenya Marine and Fisheries Research Institute; et al. (Elsevier, 2017-09-23)
      This study aimed to assess how the size-frequency distributions of coral genera varied between reefs under different fishing pressures in two contrasting Indian Ocean locations (the Maldives and East Africa). Using generalized linear mixed models, we were able to demonstrate that complex interactions occurred between coral genera, coral size class and fishing pressure. In both locations, we found Acropora coral species to be more abundant in non-fished compared to fished sites (a pattern which was consistent for nearly all the assessed size classes). Coral genera classified as ‘stress tolerant’ showed a contrasting pattern i.e. were higher in abundance in fished compared to non-fished sites. Site specific variations were also observed. For example, Maldivian reefs exhibited a significantly higher abundance in all size classes of ‘competitive’ corals compared to East Africa. This possibly indicates that East African reefs have already been subjected to higher levels of stress and are therefore less suitable environments for ‘competitive’ corals. This study also highlights the potential structure and composition of reefs under future degradation scenarios, for example with a loss of Acropora corals and an increase in dominance of ‘stress tolerant’ and ‘generalist’ coral genera.
    • Web-building spiders attract prey by storing decaying matter.

      Bjorkman-Chiswell, Bojun T.; Kulinski, Melissa M.; Muscat, Robert L.; Nguyen, Kim A.; Norton, Briony, A.; Symonds, Matthew R. E.; Westhorpe, Gina E.; Elgar, Mark A.; University of Melbourne; James Cook University (Springer, 2004-05-01)
      The orb-weaving spider Nephila edulis incorporates into its web a band of decaying animal and plant matter. While earlier studies demonstrate that larger spiders utilise these debris bands as caches of food, the presence of plant matter suggests additional functions. When organic and plastic items were placed in the webs of N. edulis, some of the former but none of the latter were incorporated into the debris band. Using an Y-maze olfactometer, we show that sheep blowflies Lucilia cuprina are attracted to recently collected debris bands, but that this attraction does not persist over time. These data reveal an entirely novel foraging strategy, in which a sit-and-wait predator attracts insect prey by utilising the odours of decaying organic material. The spider’s habit of replenishing the debris band may be necessary to maintain its efficacy for attracting prey.