The distribution of two species of alpheid shrimp, Alpheus edwardsii and A. Lobidens, on a tropical beach
| Autor: | C. G. Alexander, Jamie L. Corfield |
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| Rok vydání: | 1995 |
| Předmět: | |
| Zdroj: | Journal of the Marine Biological Association of the United Kingdom. 75:675-687 |
| ISSN: | 1469-7769 0025-3154 |
| DOI: | 10.1017/s0025315400039096 |
| Popis: | Alpheus edwardsii Audouin and Alpheus lobidens de Man (Crustacea: Decapoda: Alpheidae) are two intertidal snapping shrimp that burrow in association with rocks. They are morphologically similar and are often found in the same intertidal zone. The competitive exclusion theory states that two co-existing species must partition resources. The partitioning of food items as a resource appears unlikely, as gut content analyses revealed that the two species have similar diets and the relationship of shrimp condition and shrimp density indicates that food supply was not in limited supply. Instead the two species partition the resources of space within the intertidal zone, and shelter. The two species were found to exist largely in isolation from each other. Alpheus edwardsii occurred across much of the intertidal zone. Within this range A. edwardsii were most abundant in substrata with a low proportion (A. lobidens allows this species the potential to occupy a wide range of substratum types; however, they were found only in muddy substrata with substantial surface rock cover at tidal elevations of 1.18m above datum or below. The restriction of A. lobidens to this region of the intertidal zone is probably related, in part, to their physiological requirements. In regions of co-occurrence, A. lobidens were significantly smaller than A. edwardsii, and utilized smaller rocks as shelters, thus avoiding direct interspecific competition for this resource. The absence of large A. lobidens from these areas may reflect their ability to procure shelter in competition with A. edwardsii, as behavioural experiments conducted in this study found that A. edwardsii were the dominant competitors for this resource. |
| Databáze: | OpenAIRE |
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