Journal Articles - UP - MSI
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- Somatostatin venom analogs evolved by fish-hunting cone snails: From prey capture behavior to identifying drug leadsRamiro, Iris Bea L.; Bjørn-Yoshimoto, Walden E.; Imperial, Julita S.; Gajewiak, Joanna; Salcedo, Paula Flórez; Watkins, Maren; Taylor, Dylan; Resager, William; Ueberheide, Beatrix; Bräuner-Osborne, Hans; Whitby, Frank G.; Hill, Christopher P.; Martin, Laurent F.; Patwardhan, Amol; Concepcion, Gisela; Olivera, Baldomero M.; Safavi-Hemami, Helena (American Association for the Advancement of Science, 2022-03-25)Somatostatin (SS) is a peptide hormone with diverse physiological roles. By investigating a deep-water clade of fish-hunting cone snails, we show that predator-prey evolution has generated a diverse set of SS analogs, each optimized to elicit specific systemic physiological effects in prey. The increased metabolic stability, distinct SS receptor activation profiles, and chemical diversity of the venom analogs make them suitable leads for therapeutic application, including pain, cancer, and endocrine disorders. Our findings not only establish the existence of SS-like peptides in animal venoms but also serve as a model for the synergy gained from combining molecular phylogenetics and behavioral observations to optimize the discovery of natural products with biomedical potential.
- Fish predation on mangrove-associated penaeids: The role of structures and substratePrimavera, J. H. (Elsevier BV, 1997-08)The effect of habitat structure and substratum on predation of the greasyback shrimp Metapenaeus ensis (De Haan), white shrimp Penaeus merguiensis De Man and tiger shrimp Penaeus monodon Fabricius by sea bass Lates calcarifer Bloch and mangrove snapper Lutjanus argentimaculatus (Forsskal) was evaluated. The shrimp juveniles measured 6–15 mm in carapace length; fish measured 6.5–12.5 cm in standard length; structure types were pneumatophores of the mangrove Sonneratia griffithii Kurz and dried coconut leaf bracts; structure densities were 0, 32 and 98 pneumatophores per tank; and sediment particle sizes were pebbles, sand-granules and silt–sand. Predation on shrimp was significantly higher in controls or bare sand (48.7%) than among pneumatophores (29.9%), but not among leaf bracts (43.5%). Shrimp mortality was also significantly higher on bare sand (72.9%) compared to medium-density (54.2%), but not high-density (68.8%), pneumatophores. Fish predation on the burying shrimp M. ensis was affected by predator type but not by sediment size. The generally higher predation rates of snapper may be due to their habit of leaving unconsumed pieces of shrimp, whereas sea bass which devour whole prey require fewer shrimp to reach satiation. Moreover, the presence of structures did not affect sea bass behaviour of chasing prey among pneumatophores and under leaf bracts, but reduced predation by the relatively passive snapper. Predation rates among pneumatophores vs. control, and among medium-density pneumatophores vs. bare sand, were lower for P. monodon but not P. merguiensis. This may be related to the greater and more frequent use of (laboratory) shelters by juvenile tiger shrimp compared to white shrimp. The results demonstrate that the effective provision of shelter depends not only on structure type and density but on the behaviour of predator and prey as well. The use of mangrove structures (pneumatophores) by juvenile shrimp as refuge from predation is also documented for the first time.
- Size-dependent predation on juvenile sandfish, Holothuria scabra by seagrass-associated crabsCaasi, Olivier Josh C.; Gosselin, Louis A.; Juinio–Meñez, Marie Antonette (Cambridge University Press, 2023-10-23)High mortality of juvenile Holothuria scabra in seagrass nursery areas has been attributed to predation. In this study, laboratory and field experiments were conducted to determine the effect of the size of two seagrass–associated crabs, Thalamita crenata and Dardanus megistos, on the survival of juvenile sandfish at different sizes (1–10 g). Small juvenile sandfish (1–2 g) offered in field trials were more preferred by small Thalamita and large Dardanus. Non-lethal damage caused by both crabs were also evident, indicating differences in the mode of attack and consumption. The incidence of non-lethal wounds in medium and large juveniles in the laboratory indicate higher incidences of unsuccessful attacks by the crabs. Differences in consumption rate may be related to cheliped morphology and handling techniques, and activity patterns affecting encounter rates. Mortality rates of juvenile sandfish due to T. crenata (CW: 4.30–7.05 cm) ranged from 10–43%, while those by D. megistos (SL: 0.90–2.3 cm) was even higher at 34–53% after 24 h trials. This is the first report that a hermit crab D. megistos is a significant predator of juvenile sandfish. Results provide new insights on crab–soft-bodied prey interactions in tropical seagrass areas. These are also important considerations in stock restoration and ocean-based culture. Given that juveniles (≤10 g) are very vulnerable to predation by these common crab species, growing sandfish to larger sizes is essential prior to release in the field.This study was funded by Australian Centre for International Agricultural Research (ACIAR) through the project FIS/2016/ 122 ‘Increasing technical skills supporting community–based sea cucumber production in Vietnam and the Philippines’ and administrative support from the Marine Environment and Resources Foundation (MERF), Inc. We are grateful to the Bolinao Marine Laboratory of the University of the Philippines Marine Science Institute for the use of facilities and equipment. Special thanks to Tirso Catbagan, Garry Bucol, and Tomilyn Jan Garpa for their assistance with field and laboratory work. We also thank JayR Gorospe and Jerwin Baure for comments on the draft versions of the manuscript.