A New Genus and New Species of Nematode from the Circulatory System of the Bay Pipefish (Sygnathus leptorhynchus) in California
Jill V. Spangenberg1; Christina J. Slager1; Kevin O.
Lewand Jr.1; Andrew R. Sim1; Franticek Moravec2; Salvatore
Frasca, Jr.3
Abstract
Months after collection from San Francisco Bay, a group of Bay pipefish
(Syganthus leptorhynchus) maintained at Underwater World at Pier 39 in San Francisco
began to suffer sporadic, sub-acute mortality despite completion of a quarantine protocol,
excellent growth, and apparent good health. External examination of mortalities revealed adult
pipefish in excellent body condition, with no discernible external parasitism or other signs of
disease. Gross necropsies revealed slender thread-like nematodes located in the heart and
pericardial cavities of some individuals. Histologic examination demonstrated intra-luminal
gravid female parasites in the sinus venosus, renal, and hepatic veins. Parasitism was not
associated with pathologic changes to the walls of the sinus venosus or veins in five pipefish
examined histopathologically. However, nematode larvae surrounded by lymphohistiocytic
infiltrates were located in the interstitium of gill filaments and lamellae in 1 of 5 pipefish.
Intercurrent protozoal coelomitis, dermatitis, and encephalitis (compatible with Uronema
spp.), as well as hepatic lipidosis, were present in two, while skeletal muscle fiber
degeneration and necrosis were observed in three of the five pipefish. Further morphologic
examination of preserved whole worms indicated that the intra-luminal nematode belongs to the
super family Dracunculoidea, family Daniconematidae. The nematode, which appears to be of low
pathogenicity to the host under normal circumstances, has provisionally been classified as a new
genus and new species.
The full manuscript is currently in review (Journal of Parasitology).
Acknowledgements
The authors would like to acknowledge all Underwater World at Pier 39
husbandry and life support staff involved with the collection and maintenance of the pipefish.
The authors also wish to thank Spencer Russell, Michael Goedken, and Elizabeth Hendricks for
their assistance with necropsies and histopathology. This is contribution number 2006 from the
Storrs Agricultural Experiment Station. This study was partly supported by grant number A6022901
from the Grant Agency of the Academy of Sciences of the Czech Republic. Finally, thanks to Sarah
Poynton for her suggestion of this collaboration.