1
|
Gregorin C, Di Vito M, Roveta C, Pulido Mantas T, Gridelli S, Domenichelli F, Cilenti L, Vega Fernández T, Puce S, Musco L. Reduction of small-prey capture rate and collective predation in the bleached sea anemone Exaiptasiadiaphana. Mar Environ Res 2024; 196:106435. [PMID: 38467089 DOI: 10.1016/j.marenvres.2024.106435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 01/26/2024] [Accepted: 03/05/2024] [Indexed: 03/13/2024]
Abstract
Cnidarians may dominate benthic communities, as in the case of coral reefs that foster biodiversity and provide important ecosystem services. Polyps may feed by predating mesozooplantkon and large motile prey, but many species further obtain autotrophic nutrients from photosymbiosis. Anthropogenic disturbance, such as the rise of seawater temperature and turbidity, can lead to the loss of symbionts, causing bleaching. Prolonged periods of bleaching can induce mortality events over vast areas. Heterotrophy may allow bleached cnidarians to survive for long periods of time. We tested the reinforcement of heterotrophic feeding of bleached polyps of Exaiptasia diaphana fed with both small zooplantkon and large prey, in order to evaluate if heterotrophy allows this species to compensate the reduction of autotrophy. Conversely to expected, heterotrophy was higher in unbleached polyps (+54% mesozooplankton prey and +11% large prey). The increase of heterotrophic intake may not be always used as a strategy to compensate autotrophic depletion in bleached polyps. Such a resilience strategy might be more species-specific than expected.
Collapse
Affiliation(s)
- Chiara Gregorin
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy; Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy
| | - Marica Di Vito
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Camilla Roveta
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Torcuato Pulido Mantas
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Stefano Gridelli
- Cattolica Aquarium, Piazzale Delle Nazioni 1/A, 47841 Cattolica, Italy
| | | | - Lucrezia Cilenti
- National Research Council -National Research Council, Institute of Sciences of Food Production (CNR-ISPA), Via Michele Protano, 71121 Foggia, Italy
| | - Tomás Vega Fernández
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy
| | - Stefania Puce
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Luigi Musco
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy; Department of Biological and Environmental Sciences and Technologies, Salento University, Via Lecce - Monteroni, 73100 Lecce, Italy; NBFC, National Biodiversity Future Center, Piazza Marina, 61 90133 Palermo, Italy.
| |
Collapse
|
2
|
Gubbi S, Sharma K, Kumara V. Every hill has its leopard: patterns of space use by leopards ( Panthera pardus) in a mixed use landscape in India. PeerJ 2020; 8:e10072. [PMID: 33083134 PMCID: PMC7548080 DOI: 10.7717/peerj.10072] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 09/09/2020] [Indexed: 11/20/2022] Open
Abstract
Understanding abundance and distribution of species is often necessary for wildlife conservation. However, elusive species such as the leopard (Panthera pardus) that have wide geographical distribution and typically low abundance pose a constant challenge to conservationists due to logistical and methodological constraints. Although leopard abundance has been estimated at the scale of protected areas or other smaller regions, reliable information describing leopard distribution over large spatial scales remains largely unavailable. Knowledge about space use by leopards within landscapes could help improve conservation management, reduce human-wildlife conflict, and also facilitate population status monitoring. We carried out occupancy surveys across c. 24,000 km2 in southern India in a landscape that consisted a mosaic of leopards’ natural habitats and highly human-dominated areas. We investigated the effects of key ecological and anthropogenic variables in determining leopard space use patterns. We addressed imperfect detections obtained using sign surveys conducted on spatially replicated transects within sampling units by modeling detection as a function of spatial auto-correlation and covariates. Our results show that the probability of site-use by leopards across the landscape varied between 0.02 (95% CI [0.01–0.09]) and 0.99 (95% CI [0.99–1.0]) across the study area. The best model (AIC weight = 0.97) showed that the probability of leopard space use was affected by the proportion of natural habitats and the presence of large wild prey in the sampling unit. Given that India is undergoing rapid modifications due to economic changes and demand for natural resources, we emphasize the need for landscape-based approach for conserving and monitoring leopards. We argue that leopards are an indicator of functional ecosystems represented by scrub, deciduous forest and rocky outcrops that do not always get prioritized for conservation, unlike densely forested habitats. Similarly, conservation of natural large wild prey, especially outside the protected area system, should assume greater importance, which could also have a positive impact on reducing human-leopard conflict.
Collapse
Affiliation(s)
- Sanjay Gubbi
- Nature Conservation Foundation, Mysore, Karnataka, India.,Department of Wildlife and Management, Kuvempu University, Shankaraghatta, Karnataka, India.,Holématthi Nature Foundation, Bengaluru, Karnataka, India
| | - Koustubh Sharma
- Nature Conservation Foundation, Mysore, Karnataka, India.,Snow Leopard Trust, Seattle, WA, USA
| | - Vijaya Kumara
- Department of Wildlife and Management, Kuvempu University, Shankaraghatta, Karnataka, India
| |
Collapse
|
3
|
Abstract
Selection might favor group foraging and social feeding when prey are distributed in patches that do not last long enough for a solitary individual to consume more than a small fraction of them (Pulliam and Millikan 1982; Pulliam and Caraco 1984). Here we considered the foraging behavior of a social spider, Anelosimus eximius, in light of this ephemeral resource hypothesis. This species builds large webs in which members cooperate to capture a wide variety of different sizes and types of prey, many of which are very large. The capture success of this species was very high across all prey sizes, presumably due to the fact that they foraged in groups. Group consumption times in natural colonies for all prey larger than five mm were less than the time that dead insects remained on the plastic sheets that we used as artificial webs. Solitary consumption estimates, calculated from the rate at which laboratory individuals extracted insect biomass while feeding, were the same as the residence times of insects on artificial webs in the field for insects between 6 and 15 mm in length and were significantly longer than the persistence of insects on plastic sheets for all larger insects. Large prey, that contribute substantially to colony energy supplies, appeared to be ephemeral resources for these spiders that could not be consumed by a single spider in the time they were available. These factors made the food intake of one spider in a group less sensitive to scavenging by others and could act to reinforce the social system of this species.
Collapse
Affiliation(s)
- Ann L Rypstra
- Miami University, 1601 Peck Boulevard, 45011, Hamilton, OH, USA
| | - R Scott Tirey
- Miami University, 1601 Peck Boulevard, 45011, Hamilton, OH, USA
| |
Collapse
|