Meet Our Scientists

Dr. Arun K. Dhar

Principle Investigator

Photograph of Dr. DharDr. Dhar received his master’s and PhD at the Indian Agricultural Research Institute, where he focused on plant viruses. He spent two years in Canada doing postdoctoral research on a potato virus, which he realized was similar to a shrimp virus (Taura Syndrome Virus). He did additional postdoctoral work in Massachusetts at Tufts University, this time working with shrimp. He subsequently spent two productive years in industry, during which he published ten papers on molecular diagnostic methods and potential therapies for shrimp viruses.

In the early 2000's, he received multiple grants for various projects as he continued exploring molecular diagnostics and therapies, including oral vaccines. Over the next decade, he continued working as a teacher and researcher in both academic and industrial settings. By 2017 (when he became APL’s principle investigator), he had authored/coauthored over 50 peer-reviewed publications and obtained multiple patents. Since then, he has continued to teach, mentor, and lead APL.


Dr. Hung Nam Mai

Postdoctoral Scholar

Photograph of Dr. Mai


Dr. Mai earned his bachelor’s and master’s degrees at Cantho University in Vietnam. He received his doctorate in Applied Marine Bioscience at Tokyo University of Marine Science and Technology and spent the next few years as the Senior Technical Manager at Vietuc Seafood Corporation.

Hung joined APL in April of 2018, and has completed projects focusing on epidemiological factors of shrimp viruses, as well as viral detection and characterization.

His current areas of research are focused on shrimp population susceptibility, Photorabdus Insect-Related (Pir) toxins, and viral genome reconstruction from preserved tissue.


Dr. Russel Alenton

Postdoctoral Scholar

Photograph of Dr. Alenton


Dr. Alenton received his bachelor’s and master’s degrees at the University of Santo Tomas in the Philippines and his PhD at Tokyo University of Marine Science and Technology.

Russel has been interested in shrimp immunology since he began graduate school, and spent those years researching host-pathogen interactions with a particular focus on receptor biology.

He brings to APL a unique combination of experience with cell line research and extensive knowledge of shrimp immunology, and is working to establish a primary cell culture--in shrimp! 


Dr. Thales Passos de Andrade

Visiting Scholar

Photograph of Dr. Andrade


Dr. Andrade is a professor from Universidade Estadual do Maranhao (UEMA) in Brazil and Director of the Laboratory for Crustacean Pathology and Diagnosis (LAQUA).

Dr. Andrade has experience in Pathobiology of cultivated marine and estuarine crustaceans and fish; development of diagnostic methods, virology, histopathology, microbiology, electronic microscopy, development of SPF/SPR/SPT stocks, diagnostic laboratory design, farm/hatchery management and biosecurity.

Dr. Andrade got his graduate studies (M.SC and PhD) 2003-2009 here in the Aquaculture Pathology Laboratory. Now, he is attending a formal sabbatical primarily focused on the pathobiology and development of diagnostic methods of diseases affecting the Brazilian shrimp farming industry such as PvSV and IMNV.



Our research team is supported by additional researchers, graduate students, and undergraduate students. We collectively work together in shrimp and crustacean research with current studies and projects targeted specific to pathogens WSSV, EMS, EHP, WFD and more.



Recent APL Publications


Selected Referred Journal Articles



López-Carvallo JA, Cruz-Flores R, Dhar AK. 2022. The emerging pathogen Enterocytozoon hepatopenaei drives a degenerative cyclic pattern in the hepatopancreas microbiome of the shrimp (Penaeus vannamei). Scientific Reports. 12(1). doi:10.1038/s41598-022-19127-2.

Aranguren Caro LF, Gomez-Sanchez MM, Piedrahita Y, Mai HN, Cruz-Flores R, Alenton RRR, Dhar AK. 2022. Current status of infection with infectious hypodermal and hematopoietic necrosis virus (IHHNV) in the Peruvian and Ecuadorian shrimp industry. PLOS ONE. 17(8):e0272456. doi:10.1371/journal.pone.0272456.

Andrade TPD, Cruz-Flores R, Mai HN, Dhar AK. 2022. Novel infectious myonecrosis virus (IMNV) variant is associated with recent disease outbreaks in Penaeus vannamei shrimp in Brazil. Aquaculture. 2022; 554:738159. doi:10.1016/j.aquaculture.2022.738159.

Dhar AK, Cruz-Flores R, Warg J, Killian ML, Orry A, Ramos J, Garfias M, Lyons G. 2022. Genetic Relatedness of Infectious Hypodermal and Hematopoietic Necrosis Virus Isolates, United States, 2019. Emerging Infectious Diseases. 28(2):373–381. doi:10.3201/eid2802.211874. 


Aranguren Caro LF, Mai HN, Cruz-Flores R, Marcos FLA, Alenton RRR, Dhar AK. 2021. Experimental reproduction of White Feces Syndrome in whiteleg shrimp, Penaeus vannamei. Chen T-Y, editor. PLOS ONE. 16(12):e0261289. doi:10.1371/journal.pone.0261289.

Mai HN, Aranguren Caro LF, Cruz-Flores R, Noble White BL, Dhar AK. Differentially Expressed Genes in Hepatopancreas of Acute Hepatopancreatic Necrosis Disease Tolerant and Susceptible Shrimp (Penaeus vannamei). Frontiers in Immunology. 2021;12. doi:10.3389/fimmu.2021.634152

Mai HN, Aranguren Caro LF, Cruz-Flores R, Dhar AK. Development of a Recombinase Polymerase Amplification (RPA) assay for acute hepatopancreatic necrosis disease (AHPND) detection in Pacific white shrimp (Penaeus vannamei). Molecular and Cellular Probes. 2021;57:101710. doi:10.1016/j.mcp.2021.101710

Powers Q, Caro LF, Fitzsimmons KM, McLain JE, Dhar AK. Crayfish (Cherax quadricarinatus) susceptibility to acute hepatopancreatic necrosis disease (AHPND). Journal of Invertebrate Pathology. 2021 Feb 14:107554. doi:10.1016/j.jip.2021.107554

Aranguren LF, Alghamdi F, De Belder K, Lin J, Mai HN, Millabas J, Alrehaili Y, Alazwari A, Algetham S, Dhar AK. The Effect Of Salinity On Enterocytozoon Hepatopenaei Infection In Penaeus Vannamei Under Experimental Conditions. BMC Veterinary Research. 2021;17(1):1–8. doi:10.21203/

Cruz-Flores R, Mai HN, Dhar AK. Complete genome reconstruction and genetic analysis of Taura syndrome virus of shrimp from archival Davidson's-fixed paraffin embedded tissue. Virology. 2021;553:117–121. doi:10.1016/j.virol.2020.11.009


Agnew MV, Friedman CS, Langdon C, Divilov K, Schoolfield B, Morga B, Degremont L, Dhar AK, Kirkland P, Dumbauld B, et al. Differential Mortality and High Viral Load in Naive Pacific Oyster Families Exposed to OsHV-1 Suggests Tolerance Rather than Resistance to Infection. Pathogens. 2020;9(12):1057. doi:10.3390/pathogens9121057

Schofield PJ, Noble BL, Caro LF, Mai HN, Padilla TJ, Millabas J, Dhar AK. Pathogenicity of Acute Hepatopancreatic Necrosis Disease (AHPND) on the freshwater prawn, Macrobrachium rosenbergii, and Pacific White Shrimp, Penaeus vannamei, at various salinities. Aquaculture Research. 2020;52(4):1480–1489. doi:10.1111/are.15001

Ramírez B, Guevara M, Alfaro R, Montoya V, Mai HN, Serna M, Dhar AK, Aranguren LF. A cross‐sectional study of shrimp pathogens in wild shrimp, Penaeus vannamei and Penaeus stylirostris in Tumbes, Peru. Aquaculture Research. 2020;52(3):1118–1126. doi:10.1111/are.14969

Friedman CS, Reece KS, Wippel BJT, Agnew MV, Dégremont L, Dhar AK, Kirkland P, MacIntyre A, Morga B, Robison C, et al. Unraveling concordant and varying responses of oyster species to Ostreid Herpesvirus 1 variants. Science of The Total Environment. 2020;739. doi:10.1016/j.scitotenv.2020.139752

Aranguren Caro LF, Mai HN, Kanrar S, Cruz-Flores R, Dhar AK. A Mutant of Vibrio parahaemolyticus pirABVP (+) That Carries Binary Toxin Genes but Does Not Cause Acute Hepatopancreatic Necrosis Disease. Microorganisms. 2020;8(10):1549. doi:10.3390/microorganisms8101549

Aranguren Caro LF, Mai H, Pichardo O, Cruz-Flores R, Hanggono B, Dhar AK. Evidences supporting Enterocytozoon hepatopenaei association with white feces syndrome in farmed Penaeus vannamei in Venezuela and Indonesia. Diseases of Aquatic Organisms. 2020;141:71–78. doi:10.3354/dao03522

Ochoa LM, Cruz-Flores R, Dhar AK. Detection and Phylogenetic Analyses of Taura Syndrome Virus from Archived Davidson’s-Fixed Paraffin-Embedded Shrimp Tissue. Viruses. 2020;12(9):1030. doi:10.3390/v12091030

Cruz-Flores R, Mai HN, Kanrar S, Aranguren Caro LF, Dhar AK. Genome reconstruction of White Spot Syndrome Virus (WSSV) from archival Davidson-fixed paraffin embedded shrimp (Penaeus vannamei) tissue. Scientific Reports. 2020;10(1). doi:10.1038/s41598-020-70435-x

Aranguren Caro LF, Mai HN, Noble B, Dhar AK. Acute hepatopancreatic necrosis disease (VPAHPND), a chronic disease in shrimp (Penaeus vannamei) population raised in Latin America. Journal of Invertebrate Pathology. 2020;174:107424. doi:10.1016/j.jip.2020.107424

Mai HN, Cruz-Flores R, Dhar AK. Development of an indirect Enzyme Linked Immunoassay (iELISA) using monoclonal antibodies against Photorhabdus insect related toxins, PirAVp and PirBVp released from Vibrio spp. Journal of Microbiological Methods. 2020;176:106002. doi:10.1016/j.mimet.2020.106002

Caro LFA, Mai HN, Nunan L, Lin J, Noble B, Dhar AK. Assessment of transmission risk in WSSV-infected shrimp Litopenaeus vannamei upon cooking. Journal of Fish Diseases. 2020;43(4):403–411. doi:10.1111/jfd.13128

Gangnonngiw W, Bunnontae M, Phiwsaiya K, Senapin S, Dhar AK. In experimental challenge with infectious clones of Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV), MrNV alone can cause mortality in freshwater prawn (Macrobrachium rosenbergii). Virology. 2020;540:30–37. doi:10.1016/j.virol.2019.11.004

Sullivan TJ, Dhar AK, Cruz-Flores R, Bodnar AG. Rapid, CRISPR-Based, Field-Deployable Detection Of White Spot Syndrome Virus In Shrimp. Scientific Reports. 2019;9(1). doi:10.1038/s41598-019-56170-y


Oakey J, Smith C, Underwood D, Afsharnasab M, Alday-Sanz V, Dhar A, Sivakumar S, Hameed ASS, Beattie K, Crook A. Global distribution of white spot syndrome virus genotypes determined using a novel genotyping assay. Archives of Virology. 2019;164(8):2061–2082. doi:10.1007/s00705-019-04265-2

Cruz-Flores R, Mai HN, Noble BL, Schofield PJ, Dhar AK. Detection of Enterocytozoon hepatopenaei using an invasive but non-lethal sampling method in shrimp (Penaeus vannamei). Journal of Microbiological Methods. 2019;162:38–41. doi:10.1016/j.mimet.2019.05.008

Dhar AK, Cruz-Flores R, Caro LFA, Siewiora HM, Jory D. Diversity of single-stranded DNA containing viruses in shrimp. VirusDisease. 2019;30(1):43–57. doi:10.1007/s13337-019-00528-3

Cruz-Flores R, Mai HN, Dhar AK. Multiplex SYBR Green and duplex TaqMan real-time PCR assays for the detection of Photorhabdus Insect-Related (Pir) toxin genes pirA and pirB. Molecular and Cellular Probes. 2019;43:20–28. doi:10.1016/j.mcp.2018.12.004

Dhar AK, Piamsomboon P, Aranguren Caro LF, Kanrar S, Adami R, Juan Y-S. First report of acute hepatopancreatic necrosis disease (AHPND) occurring in the USA. Diseases of Aquatic Organisms. 2019;132(3):241–247. doi:10.3354/dao03330


Aranguren LF, Dhar AK. Detection and quantification of Hepatobacter penaei bacteria (NHPB) by new PCR and quantitative PCR assays. Diseases of Aquatic Organisms. 2018;131(1):49–57. doi:10.3354/dao03285

Kanrar S, Dhar AK. Complete Genome Sequence of a Novel Mutant Strain of Vibrio parahaemolyticus from Pacific White Shrimp (Penaeus vannamei). Genome Announcements. 2018;6(24). doi:10.1128/genomea.00497-18

Jariyapong P, Pudgerd A, Weerachatyanukul W, Hirono I, Senapin S, Dhar AK, Chotwiwatthanakun C. Construction of an infectious Macrobrachium rosenbergii nodavirus from cDNA clones in Sf9 cells and improved recovery of viral RNA with AZT treatment. Aquaculture. 2018;483:111–119. doi:10.1016/j.aquaculture.2017.10.008

Responsible Seafood Advocate Articles

The Advocate contains various aquaculture-related news features and technical articles.

Below are blurbs from content authored by our lab members, with links to the original articles.

Cephalothorax (head + thorax) of Pacific white shrimp (Litopenaeus vannamei) displaying white discoloration of the gastrointestinal tract. Results of this study demonstrated for the first time the experimental reproduction of WFS under laboratory conditions when shrimp are concurrently infected with EHP and V. parahaemolyticus.

Aquaculture Pathology Laboratory finds conclusive evidence that EHP is not the only pathogen associated with the presence of White Feces Syndrome in Litopenaeus vannamei.

February 28, 2022
Shrimp from one of the challenge studies. Animal on the bottom is affected by AHPND while the one top is normal. Note coloration of the hepatopancreas in each animal.

Study is first to report a ‘lingering phase’ of this important disease.

August 17, 2020
Figure from the article containing images of stomach cuticular epithelia of specimens following various experimental conditions.

This study evaluated the transmission risk of WSSV-infected Pacific white shrimp, and results showed that the shrimp are not infectious after boiling for at least 1 minute.

April 6, 2020
Photo collage from article

From our study, there is a strong association between White Feces Syndrome (WFS) and EHP in EHP-endemic regions. EHP in combination with other enteric pathogens (including SHPN) and a possible unknown factor(s) can cause White Feces Syndrome.

April 29, 2019