Record Details
Field | Value |
---|---|
Title | The behavior of the pea crab Fabia subquadrata in relation to its mussel host, Mytilus californianus |
Names |
Lidrich, Joseph Stanley
(creator) Wiens, John A. (advisor) |
Date Issued | 1969-08-14 (iso8601) |
Note | Graduation date: 1970 |
Abstract | The pea crab Fabia subquadrata is frequently found as a symbiont of mussels, living within the mantle cavity. This study examined the nature of this symbiotic relationship by recording the pattern of distribution of individuals in a mussel bed, testing responsiveness to host secretions, and observing the feeding mechanics and behavior of Fabia. Individual pea crabs were unevenly distributed in an intertidal bed of Mytilus californianus at Yaquina Head, near Newport, Oregon. The greatest degree of infestation (25%) was in the largest mussels which were subjected to the most nearly continuous water cover. This pattern of distribution was attributed to a combination of the feeding behavior of the crab and the effects of tidal level. The responsiveness of Fabia to chemical secretions of the mussels was tested by presenting liberated crabs with a choice between sea water conditioned by live mussels and water drawn directly from Yaquina Bay. Tests were conducted to determine the role of sex and maturation, by dividing the pea crabs into three groups: immature females, adult females, and adult males. The effects of light, darkness, and deprivation of its habitat (the host) were also tested. Under these various test conditions, Fabia showed no measurable response to any host factor from Mytilus. When the crab was inside the mussel it faced the posterior and fed by intercepting the major mucus strand in the food groove of a ctenida. This behavior took full advantage of the feeding tracts of the mussel. When outside the host in undisturbed aquaria, crabs fed on feces and mucus ejected by mussels. This feeding behavior may play a role in the selection and invasion of a host. Quantitative measurements indicated that the feeding on Mytilus by adult female crabs had no significant effects on five parameters used to determine the condition of infested mussels. The life span of adult female crabs was estimated to be more than two years and less than eight years. The adult male's life span was two years at best with most surviving only a year. Female crabs were capable of producing live zoea from stored sperm for at least two years and possibly more. |
Genre | Thesis/Dissertation |
Topic | Fabia subquadrata |
Identifier | http://hdl.handle.net/1957/45713 |