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Updated: Jun 3, 2026
A Precise and Quantifiable Method for Collecting Hemolymph from Small Arthropods
Published on: April 28, 2023
Milky hemolymph syndrome (MHS) in spiny lobsters, penaeid shrimp and crabs
Linda M Nunan1, Bonnie T Poulos, Solangel Navarro
1Department of Veterinary Science and Microbiology, University of Arizona, Tucson, Arizona 85721, USA. lmn@email.arizona.edu
Abstract:
Black tiger shrimp Penaeus monodon, European shore crab Carcinus maenas and spiny lobster Panulirus spp. can be affected by milky hemolymph syndrome (MHS). Four rickettsia-like bacteria (RLB) isolates of MHS originating from 5 geographical areas have been identified to date. The histopathology of the disease was characterized and a multiplex PCR assay was developed for detection of the 4 bacterial isolates. The 16S rRNA gene and 16-23S rRNA intergenic spacer region (ISR) were used to examine the phylogeny of the MHS isolates. Although the pathology of this disease appears similar in the various different hosts, sequencing and examination of the phylogenetic relationships reveal 4 distinct RLB involved in the infection process.
Insights
Milky hemolymph syndrome (MHS) affects shrimp, crabs, and lobsters. Researchers identified four distinct rickettsia-like bacteria (RLB) causing MHS, despite similar disease pathology across hosts.
Area of Science:
- Aquatic animal health
- Microbiology
- Molecular diagnostics
Background:
- Milky hemolymph syndrome (MHS) impacts commercially important crustaceans like shrimp, crabs, and lobsters.
- Previous studies have identified rickettsia-like bacteria (RLB) associated with MHS, but their diversity was not fully understood.
Purpose of the Study:
- To characterize the histopathology of MHS in various crustacean species.
- To develop a diagnostic tool for identifying different RLB isolates.
- To investigate the phylogenetic relationships among MHS-causing RLB.
Main Methods:
- Histopathological examination of infected crustacean tissues.
- Development and application of a multiplex PCR assay for detecting four distinct RLB isolates.
- Phylogenetic analysis using 16S rRNA gene and 16-23S rRNA intergenic spacer region (ISR) sequencing.
Main Results:
- Histopathology revealed similar disease presentation across different crustacean hosts.
- A multiplex PCR assay was successfully developed for simultaneous detection of four RLB isolates.
- Phylogenetic analysis confirmed the presence of four distinct RLB species responsible for MHS.
Conclusions:
- Despite similar clinical signs, MHS in crustaceans is caused by at least four genetically distinct RLB.
- The developed multiplex PCR assay is a valuable tool for diagnosing MHS and identifying specific RLB strains.
- Further research into the specific impact and host-pathogen interactions of each RLB is warranted.
