The staghorn sculpin Leptocottus armatus is abundant in the
Yaquina Bay estuary on the central Oregon coast and also occurs
offshore in shallow water. A total of 560 L. armatus were collected
at three locations in Yaquina Bay and between 7 and 11 kilometers
offshore in depths of 40 to 80 meters. Staghorn sculpins were present
in all areas where collections were made throughout the year except
during the summer when most offshore sculpins moved into Yaquina
Bay. Leptocottus armatus spawned primarily in the bay during the
fall and early winter. The young fish remained in Yaquina Bay for
about one year at which time they were about 12.0 cm in length.
Subsequently, some of them moved offshore.
Seventeen different species of parasites were collected from
the 526 L. armatus examined.
Genolinea laticauda was collected from the stomachs of 25.1%
of the fish and had greater incidence and intensity in larger fish.
Recruitment of immature forms began in April and the average life
span was about seven months. The life cycle was most efficient in the
lower estuary.
Tubulovesicula lindbergi occurred in the stomachs of 50.8% of
the fish and had greater incidence and intensity in small fish. Recruitment
of immature individuals occurred all year, but was greatest in
June. The life cycle was most efficient in the upper estuary.
Podocotyle atomon was found in 42.6% of the fish and was most
abundant in the larger fish.
Bucephalopsis ozakii was collected in 38.8% of the L. armatus
and was more abundant in large fish, as were larval tetraphyllidean
cestodes which were present in 40.7% of the fish. These two parasites
were found to be positively associated because they were both
more likely to parasitize larger fish.
Nematodes believed to be Contracaecum cornutum were found
in ulcers in the stomach of 28.0% of the fish. This was the only
parasite that was obviously pathogenic.
Echinorhynchus gadi occurred in 47.4% of the fish. Immature
worms were obtained all year, but only from fish in the upper estuary.
Other parasites encountered were the protozoans Scyphidia sp.,
Trichodina sp. and Ceratomyxa sp.; the trematodes Gyrodactylus sp.,
Neopodocotyloides sinusaccus and Derogenes sp.; the nematode
Contracaecum aduncum; a piscicolid leech; the copepod
Acanthochondria rectangularis and the isopod Lironeca vulgaris.
It was concluded that all the parasites of L. armatus could be
acquired in Yaquina Bay, although it was more likely that the larval
cestode was acquired offshore.
The parasite data could not be used to determine movements
of L. armatus in and out of Yaquina Bay, but the data were utilized
to show that movements between the upper and lower estuary were
not extensive. / Graduation date: 1973
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28621 |
| Date | 29 September 1972 |
| Creators | Burreson, Eugene Michael |
| Contributors | Pratt, Ivan |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
Page generated in 0.0092 seconds