The Ecological Ramifications of Disease and Density in the Caribbean Spiny Lobster, <i>Panulirus argus</i>

<p>In 1999, I discovered the first virus known to be pathogenic to any species of lobster. HLV-PA is a pathogenic herpes-like virus that infects juvenile Caribbean spiny lobster, <em>Panulirus argus</em>, in the waters off south Florida (USA), and it alters the behavior and ecology of this species in fundamental ways. Gross signs of HLV-PA infection are lethargy, morbidity, cessation of molting, and discolored, “milky” hemolymph that does not clot. HLV-PA infects the hemocytes of host lobsters, specifically the hyalinocytes and semi-granulocytes, but not the granulocytes. When hemolymph from infected donors was injected into healthy juvenile lobsters, 90% of the healthy individuals became infected within 80 days. In another set of laboratory trials, 40% of the juvenile lobsters that ingested conspecific tissue infected with HLV-PA developed the disease, and in a third experiment wherein transmission by contact or waterborne means was tested, 63% of the lobsters(CL), 33% of lobsters 30–40 mm CL and 10% of lobsters 40–50 mm CL became infected within 80 days.</p> <p>In field surveys from 2000–2001, up to 40% of the juveniles at each of twelve sites (mean = 8%) had the disease. The disease was most prevalent (mean = 16%) among the smallest juveniles (i.e.,CL) and, thus far, appears limited to juveniles. However, all of the surveys of disease prevalence are based on gross, visual signs of late stages of infection, and are, therefore, conservative estimates. A diagnostic tool to assess infection at earlier stages has not yet been developed.</p> <p>Field observations and laboratory experiments indicate that healthy juvenile lobsters avoid diseased conspecifics, which is only the second report of such behavior in any animal. The prevalence of the disease in wild lobster populations is not correlated with population density, even when lobsters were experimentally concentrated at sites with artificial shelters. Moreover, enhanced density does not appear to have a detrimental effect on population dynamics such as nutritional condition and short-term residency, likely due to their normal gregariousness. Thus, juvenile spiny lobsters appear to have developed remarkable contradictory behaviors, avoidance of infected conspecifics and gregariousness, both of which may ultimately enhance survival of uninfected lobsters.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biological Sciences

Year dc:date.available

2003

Author dc:creator

• Behringer, Donald C., Jr.

Contributors dc:contributor

• Mark J. Butler, IV
• Kent E. Carpenter
• Jeffrey D. Shields

• Caribbean
• Disease
• Panulirus argus
• Spiny lobster
• Animal Diseases
• Aquaculture and Fisheries
• Marine Biology

Statement dc:rights

• <p>In Copyright. URI: <a href="http://rightsstatements.org/vocab/InC/1.0/">http://rightsstatements.org/vocab/InC/1.0/</a> This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).</p>

Identifier

9780496511259

OAI identifier oai:identifier

oai:digitalcommons.odu.edu:biology_etds-1050