Aktedrilus
Aktedrilus Knollner, 1935 (ref. ID; 3692, 6913)
Family Tubificidae: Subfamily Phallodrilinae Brinkhurst (ref. ID; 5945)
- Aktedrilus brevis Erseus, 1980 (ref. ID; 6576)
- Aktedrilus cuneus Erseus, 1984 (ref. ID; 6618, 6661)
- Aktedrilus curvipeni (ref. ID; 5882)
- Aktedrilus floridensis (ref. ID; 5882)
- Aktedrilus locyi Erseus, 1980 (ref. ID; 6576) reported author and year? (ref. ID; 5882)
- Aktedrilus magnus Erseus, 1980 (ref. ID; 6576, 6618)
- Aktedrilus mediterraneus (Erseus, 1980) (ref. ID; 6618)
- Aktedrilus monospermathecus Knollner, 1935 (ref. ID; 3692, 5912, 6618) reported author and year? (ref. ID; 5882)
- Aktedrilus oregonensis Strehlow, 1981 (ref. ID; 6576 original paper) reported author and year? (ref. ID; 5882)
- Aktedrilus parviprostatus (ref. ID; 5882)
- Aktedrilus sardus Erseus, 1987 (ref. ID; 6618)
- Aktedrilus sphaeropenis (ref. ID; 5882)
- Aktedrilus svetlovi Finogenova (ref. ID; 7879)
Aktedrilus cuneus Erseus, 1984 (ref. ID; 6618, 6661)
Descriptions
Marine species. (ref. ID; 6618)
Descriptions
Marine species. (ref. ID; 5882)
Descriptions
Marine species. (ref. ID; 5882)
Aktedrilus locyi Erseus, 1980 (ref. ID; 6576) reported author and year? (ref. ID; 5882)
Descriptions
Marine species. (ref. ID; 5882)
Aktedrilus magnus Erseus, 1980 (ref. ID; 6576, 6618)
Descriptions
Marine species. (ref. ID; 6618)
Descriptions
Marine species. (ref. ID; 6618)
Aktedrilus monospermathecus Knollner, 1935 (ref. ID; 3692, 6618) reported author and year? (ref. ID; 5882)
Descriptions
Marine species. (ref. ID; 5882, 6618)
See the description of Phallodrilus. (ref. ID; 5912)
Aktedrilus oregonensis Strehlow, 1981 (ref. ID; 6576 original paper) reported author and year? (ref. ID; 5882)
Descriptions
Marine species. (ref. ID; 5882)
Fixed specimens 2.1-3.7 mm long, 28-35 segments; anterior end (segments 0-X) 0.65-0.88 mm long. Diameter of fixed, slightly compressed specimens 0.10-0.11 mm at segment V, 0.14-0.18 mm at XI, and 0.09-0.11 mm at XX. Clitellum well developed per segments 1/2X-XII. All setae bifid with upper tooth shorter and thinner than lower. Setae 30-35 µm long and about 1 µm in diameter; 2-4(5) setae per bundle throughout body. Ventral setae absent in XI. Male and spermathecal pores as in generic definition.
Pharyngeal glands present in IV-VI, small in VI.
Male ducts are paired. Vasa deferentia: thin walled, 5-6 µm in diameter, and shorter than atria. Atria: cyclindrical, 80-110 µm long, 14-21 µm in diameter with an outer muscle layer about 0.6 µm thick, and an inner granulated and ciliated epithelium 5-8 µm thick. Each atrium terminates in a curved, strongly cuticularized penis 27-30 µm long with an 11-13 µm diameter base and a 4-6 µm diameter shaft. A large anterior prostate is attached to the ental end of each atrium near the attachment of the vas deferens. A large posterior prostate is broadly attached mediodorsally to each penial sac and merges with the atrium at the base of the penis; a papilla extends ventrally from the posterior prostate along the inner wall of the penial sac. A second glandular papilla is attached ventrally to the ectal end of the atrium at its juncture with the penis and extends ventrally along the inner anterolateral wall of the penial sac; there is no direct connection between this papilla and the posterior prostate. Both papillae are attached throughout their length to the wall of the penial sac. The penial sac is roughly 20-25 µm wide and 55-65 µm deep.
The unpaired spermatheca is oblong, 50-65 µm long and 25-40 µm wide; the ampulla is 27-34 µm long. The lumen of the duct is nearly as voluminous as that of the ampulla and is surrounded by glandular cells. Spermatozoa are often found in the duct but are never embedded in the duct lining. Spermatozoa are embedded in the inner epithelial lining of the ampulla. (ref. ID; 6576)
Remarks
The organization of the male ducts in Aktedrilus oregonensis is similar to that originally described in A. brevis Erseus (1980). Differences between the species are the existence, in A. brevis, of an anterior lobe of the posterior prostate external to the penial sac and larger penes. Total length of worm and setal numbers are greater for A. oregonensis than A. brevis but these characters are not regarded as taxonomically definitive (Erseus 1980). The spermathecae of these two species are different. Aktedrilus brevis has a ductless saccate spermatheca with spermatozoa scattered throughout, whereas A. oregonensis possesses a spermatheca with a distinct duct and spermatozoa closely associated with, and embedded in the ampullar lining. Erseus (1980) notes that the spermatozoa in the spermatheca of Aktedrilus magnus Erseus, 1980 also appear to penetrate the ampullar lining. A similar situation occurs in the spermatheca of the polychaete Spirorbris spirorbis (L.) where it is thought to aid in sperm nutrition and storage (Daly and Golding 1977). None of the A. oregonensis specimens from Powell River, B.C., had a voluminous spermathecal duct. The paucity of specimens and geographical records makes it impossible to determine whether the observed difference in spermathecae is genetic, phenotypic, or related to reproductive state. In all other respects A. oregonensis specimens from Powell River B.C., conform to the description based on the material from the type locality. (ref. ID; 6576)
Type locality
Coos Bay, Oregon, U.S.A. A beach in the lower estuary immediately south of the North Bend Airport, in silty sand between +0.6 and +1.1 m mean lower low water, rarely as low as 0 m or as high as +1.8 m. (ref. ID; 6576)
Type materials
Holotype: 68723 USNM, whole mounted specimen. (ref. ID; 6576)
Paratypes: 68724 USNM, four whole mounted specimens from the type locality. The type series of A. oregonensis n. sp. is deposited in the United States National Museum of Natural History (USNM), Smithsonian Institution, Washington, D.C. (ref. ID; 6576)
Other material examined: Fifteen whole mounted mature specimens from the type locality. Four whole mounted mature specimens from Powell River, B.C., Canada (49 degrees 52'N, 124 degrees 34'W), loaned by Mr. H.R. Baker. (ref. ID; 6576)
Descriptions
Marine species. (ref. ID; 5882)
Descriptions
Marine species. (ref. ID; 6618)
Descriptions
Marine species. (ref. ID; 5882)