Prevalence of Trypanorhynch Plerocerci (Cestoda) in Wild and Cultured Kahala, Seriola sp. in Hawai‘i.

World Aquaculture Society May 9-13, 2006 Firenze (Florence), Italy Clyde S. Tamaru, Ruth Ellen KlingerBowen, Bruce Anderson, Douglas Vincent

Presentation at a Glance • Aknowledgements – Funding and in kind support – Technical support

• Challenge and Opportunity • What is a Trypanorhynch Plerocerci? – – – –

Anatomy Life Cycle Types Locations where they are found in the body.

• Materials and Methods • Results • Conclusions

AKNOWLEDGEMENTS Funding and In Kind Support • USDA CSREES • AQUACULTURE DEVELOPMENT PROGRAM • UH SEA GRANT COLLEGE PROGRAM • UH COLLEGE OF TROPICAL AGRICULTURE AND HUMAN RESOURCES • ANUENUE FISHERIES RESEARCH CENTER

AKNOWLEDGEMENTS Technical Support • • • • • • • • • •

Lei Yamasaki Dee Montgomery Brock Neil Hazama Brooks Takenaka Dennis Kamikawa Nelson Aberilla Lois Ann Kiehl Federico Jose Rotmann Dale Sarver Neil Anthony Sims

Challenge and Opportunity • Kahala were historically a very important commercial species. • Wild kahala is also known to be ciquatoxic and subsequently have been excluded from commercial markets by retailers and restaurants.

Challenge and Opportunity • Consumers have expressed concerns about the occurrence of worms in Kahala which have the appearance of cooked spaghetti noodles. • The worms clearly impact the aesthetics of fresh fillets and the culinary presentations expected of sashimi and sushi dishes.

Heavy infestations of similar kinds of worms in other fish species have reduced the market value of the infected fish to that of fish meal or pet food. • Mehl, J.A. P. 1970. Two flesh parasites of barracouta (Teleosti: Gempylidae) from eastern Cook Strait. N.Z.J. Mar. Freshwat. Res. 3:241-247. • Seyda, M. 1976. On a case of a mass invasion of cestode Gymnorhyncus (Gymnorhyncus) gigas (Cuvier, 1817) larvae in muscles of Brama raii (Bloch, 1791). Acta Ichthyologica Et Piscatoria. 6:59-65. • Overstreet, R.M. 1978. Trypanorhynch infections in the flesh of sciaenid fishes. Marine Fisheries Review. 40:37-38.

Challenge and Opportunity • Kahala have recently been cultivated at aquaculture facilities in Hawai‘i. • If cultured amberjack can be demonstrated to be free of ciguatoxin or worms, it would be the prelude to re-opening a once lucrative market locally and abroad and forms the basis for this project.

Kona Blue Water Farms

Kona Blue Water Farms

EVALUATING THE RISK OF CIGUATERA FISH POISONING FROM CONSUMPTION OF REEF FISH GROWN AT MARINE AQUACULTURE FACILITIES IN HAWAI‘I

May 9-13, 2005 Bali, Indonesia Clyde S. Tamaru, Bruce Anderson, Yoshistugi Hokama and Douglas Vincent

KONA BLUE DEPLOYS AND STOCKS OPEN OCEAN FISH FARM CAGES Environmentally Friendly Offshore Farm Now Stocked with Kona Kampachi™ KONA, (BIG ISLAND) HAWAII, April 4, 2005 - Kona’s first open ocean fish farm was stocked last week with over 30,000 juvenile Kona Kampachi™.

What is a Trypanoryhnca Plerocerci? It is a particular life stage of a worm: (Larval Tapeworm) WORMS: HELMINTHES • Annelida (segmented worms) • Nematoda (round worms) • Platyelminthes (flatworms) – Turbellaria: This class contains all the free-living flatworms. – Trematoda: All flukes, including the liver fluke. All are parasitic. – Cestoda: Includes all the tapeworms. All forms are parasitic. • Order: Trypanorhyncha: cestodes that mature in elasmobranchs and often use teleost fishes as intermediate or transport hosts.

Anatomy of an Adult Tapeworm • They each have a scolex (head) which bears a circle of hooks that attaches to the intestinal wall. • Protoglottids filled with eggs constantly bud off as the mature and leave with the hosts feces. • Tapeworms do not contain digestive tracts but get their nourishment by absorbing partially digested substances from the host.

Scolex

Protoglottids

Life Cycle of Trypanorhynch Plerocerci: Larval Tapeworm • • • • • •

The adult tapeworm resides in the gastrointestinal tract of a shark. Eggs (A) are passed out into the aquatic environment via the feces. Corracidium (B – D larval stages) are ultimately consumed by a crustacean. Infected crustacean (E) is eaten by a suitable host fish (F). (3 species model) The tapeworm larva develops into a plerocercoid (G). Infected fish is eaten by a shark where the plerocercoid will lodge itself in the intestinal tract of the shark completing the life cycle.

Kahala

Aku

plerocercoid copepod From: Deardoff, et al., 1984

Types of Cestode Worms • Identification of trypanorynch plerocercoid is largely based on the morphology of the scolex and the size, pattern, and number of hooks on their tentacles (Overstreet, 1978). • The plerocercoid found in the kahala is not the same as that found in aku and was first identified as Pseudogrillotia sp. (Deardoff et al., 1984) • The plerocoid in kahala is currently thought to be Protogrillotia zerbiae as described by Palm (1995).

Trypanorhynch Plerocerci In Kahala and Aku Kahala head with exposed plerocerci

Aku belly with 31 plerocerci

pleroceri from aku

Scanning electronmicrograph of pleroceri in kahala 1 mm

From: Deardoff, et al., 1984

200 um Extreme closeup of hooks

1 mm

Locations that Trypanorhynch Plerocerci can be found in Kahala

Single worm curled up can look like several worms

Material and Methods •

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10 individuals were purchased from Kona Blue Water Farms four separate times during the study period (n=40). A total of 45 kahala (22 S. dumerili and 23 S. rivoliana) were caught from the wild. Body weight and length were obtained for each fish. Examination for the presence or absence of the plerocerci began by making an incision between the eyes and parallel to the body. This was then followed by filleting the fish on both sides. Each fish were scored for the presence or absence of pleroceri.

Average Body Weights of Kona KampachiTM from Kona Blue Water Farms

N=10

N=10

N=10

N=10

Seriola dumerili, Greater Amberjack

Seriola rivoliana, Almaco Jack

Results With Wild Caught Kahala • Of the 23 wild-caught S. dumerili examined, 86.9% (20/23) were infected. • Of the 22 wild-caught S. rivoliana 72.7% (16/22) were infected. • No statistical differences (P>0.5, Chi Square = 0.1) with regard to the presence of trypanorynch plerocerci could be detected between the two wildcaught species. • The overall percentage of kahala infected with plerocerci was 80% (36/45). • Infected wild caught kahala differed significantly (P