A Contribution to the Life History of Bucephalus longicornutus (Manter, 1954)
Description
Description
(Based on 50 living and 10 fixed and stained specimens. Body, tail stem and furcae dimensions are given in Table I, p. 15).
A cercaria is small, opaque, and consists of a body, tail stem and furcae (Text-fig. 3, A). Body tapered anteriorly, pear-shaped and depressed when contracted (Text-fig. 3, A; 4, D), elongate and cylindrical when expanded (Text-fig. 4, A; 4, F). Greatest width contracted is at about mid-body level. Small, diagonally arranged, blunt spines are distributed over anterior half of body, and these merge with irregularly shaped cuticular plates which form a mosaic over posterior half of body (Text-fig. 3, C). Numerous, irregularly shaped cystogenous granules, 4μ to 15μ by 2μ to 9μ,? are distributed throughout parenchyma and impart opacity to body. These granules are concentrated in posterior half of body, becoming sparser anterior to pharynx. Central region of body is almost completely devoid of granules and accordingly less opaque. Flask-shaped cystogenous organ, 32μ to 35μ long by 22μ to 25μ at its widest point, is situated near anterior extremity (Text-fig. 3, A). Its external surface is partly covered by granules of similar appearance and texture to cystogenous granules in parenchyma. Neck of cystogenous organ encloses posterior half of a narrow duct at posterior end of which, and within cystogenous organ, is a mass of gland cells. This duct of cystogenous organ opens anteriorly by a small pore which is surrounded by four lips. Neutral red stains cystogenous granules in body stain dull pink to orange indicating neutrality, and cystogenous organ bright red indicating acidity.
An H-shaped ganglionic mass lies just posterior to cystogenous organ (Text-fig. 4, A, C). Anterior and longitudinal nerve trunks arising from this were not seen.
Mouth is a small transverse slit, 5μ to 6μ wide, surrounded by cuticular plates, situated 30μ to 40μ from posterior extremity depending on state of contraction of body. Little or no prepharynx. Pharynx more or less spherical, 12μ to 16μ in diameter, followed by a short oesophagus; intestine sacculate, up to 75μ long by 20μ to 25μ wide, and lined by a cuboidal epithelium. Peristaltic contractions of intestine occur, but no food inclusions seen in intestine.
Usual number of body wall layers present (Text-fig. 3, F). A band of muscles (2μ?thick) lies immediately within cuticle but separate longitudinal and circular fibres could not be seen. Parenchyma contains a few oblique muscle fibres. Mucus cells surround oesophagus.
Rudimentary genital pore is situated 10μ?from posterior extremity. Genital anlagen consists of two lobed masses of densely staining nuclei posterior to pharynx, each about 30μ long by 10μ wide (Text-fig. 4, A and C).
Excretory pore is at posterior extremity of body. Excretory vesicle is saccular and extends to left of pharynx. Excretory tubules open into excretory vesicle approximately midway along its length. Flame cell formula is 2[(3 + 3 + 3) + (3 + 3 + 3)] = 36 (Text-fig. 4, B). Elimination of liquid from the excretory vesicle takes place as indicated in Text-fig. 5, A-C.
Tail stem is unspined. A parenchymatous layer within the cuticle is continuous with an axial strand of parenchyma and muscle fibres. A single row of cystogenous granules lies within cuticle along posterior surface of tail stem, apart from axial strand region where granules may be four or five rows deep. A few scattered granules are distributed through axial strand. Lumen of tail stem contains a few oily droplets.
page 15Furcae are sub-circular in section, unspined, tapered distally and flattened against tail stem proximally. Highly contractile, varying between 1.3 and 18 times as long as body. Two rows of cystogenous granules, 6μ wide by 2μ long in ventral view, by 6μ tall in lateral view, lie along ventral surface of furcae (Text-fig. 3, D and E).
Text-fig. 5.—Bucephalus longicornutus. Elimination of liquid from the excretory vesicle. For abbreviations see p. 9.
Average | Range of 50 specimens | |
---|---|---|
Body length contracted | 0.150 | 0.120–0.168 |
Body length expanded | 0.250 | 0.210–0.290 |
Tail stem width | 0.100 | 0.085–0.110 |
Tail stem length | 0.044 | 0.036–0.049 |
Greatest body width contracted | 0.096 | 0.090–0.108 |
Greatest body width expanded | 0.060 | 0.056–0.068 |
Furca contracted | 0.275 | 0.200–0.286 |
Furca expanded | 3.900 | 3.810–4.100 |
Width of axial strand | 0.026 | 0.020–0.032 |
Date | Author | Host | Name given to Species | Locality |
---|---|---|---|---|
1827 | von Baer | Unio pictorum | Bucephalus polymorphus | Europe (F) |
1827 | von Baer | Anodonta anatina | B. polymorphus | Europe (F) |
1827 | von Baer | A. cellensis | B. polymorphus | Europe (F)page 16 |
1848 | Siebold | A. cellensis | B. polymorphus | Europe (F) |
1854 | Lacaze-Duthiers | Ostrea edulis | B. haimeanus | Mediterranean (S) |
1854 | Lacaze-Duthiers | Cardium rusticum | B. haimeanus | Mediterranean (S) |
1857 | Pagenstecher | A. anatina | B. polymorphus | Europe (F) |
1863 | Claparede | Found free swimming cercaria | B. haimeanus | Normandy (S) |
1874 | McCrady | Crassostrea virginica | B. cuculus | Carolina (S) |
1878 | Ulicny | A. cellensis | B. intermedius 1 | Europe (F) |
1881 | Ercolani | U. pictorum | Cercaria bucephalus 1 | Europe (F) |
1881 | Levinsen | Modiolaria discors | B. crux | Egedesminde (S) |
1882 | Ercolani | A. anatina | C. bucephalus 1 | Europe (F) |
1883 | Ziegler | — | B. polymorphus | Europe (F) |
1888 | Huet | Cardium edule | B. haimeanus | Normandy (S) |
1890 | Nelson | Crassostrea virginica | "Gregarinoid parasites" | New Jersey, U.S.A. (S) |
1893 | Huet | Mactra solida | B. haimeanus | Normandy (S) |
1893 | Nelson | Crassostrea virginica | B. cuculus | New Jersey, U.S.A. (S) Europe (S) |
1894 | Vaullegeard | Tapes pullastra | B. haimeanus | |
1894 | Vaullegeard | Tapes decussatus | B. haimeanus | Europe (S) |
1899 | Kelly | Unionidae | B. polymorphus | Mississippi R. (F) |
1903 | Haswell | Mytilus latus | B. sp. | New Zealand (S) |
1904, 05 | Johnstone | Cardium edule | B. haimeanus | England (S) |
1905, 06 09 | Tennent | Crassostrea virginica | B. haimeanus 2 | East Coast, U.S.A. (S) |
1906 | Pelseneer | Syndosmya alba | B. haimeanus | Europe (S) |
1906 | Pelseneer | Cardium edule | B. haimeanus | Europe (S) |
1907 | Pelseneer | Mactra solida | B. haimeanus | Europe (S) |
1907 | Pelseneer | Mactra subtruncata | B. haimeanus | Europe (S) |
1907 | Pelseneer | Donax trunculus | B. haimeanus | Europe (S) |
1909 | Sinitzin | Dreissensia polymorpha | B. polymorphus | Warsaw (F) |
1909 | Sinitzin | A. mutabilis | B. polymorphus | Warsaw (F) |
1909 | Sinitzin | Tapes rugatus | B. haimeanus | Black Sea (S) |
1911 | Sinitzin | Tapes rugatus | C. hydriformis 3 | Black Sea (S) |
1911 | Lebour | Cardium edule | B. haimeanus | England (S)page 17 |
1911 | Lebour | S. alba | B. syndosmyae | England (S) |
1924 | Wunder | — | B. polymorphus | Europe (F) |
1925 | Miller | Pinna carnea | Cercaria N | Tortugas (S) |
1928 | Faust | Modiola capensis | Bucephalopsis modiolae | Sth. Africa (S) |
1929 | Woodhead | Elliptio dilatatus | Bucephalus papillosum 4,8 | Michigan (F) |
1930 | Woodhead | Eurynia iris | B. elegans 8 | Michigan (F) |
1933 | Roughley | O. commercialis | B. haimeanus | N.S.W. (S) |
1933 | Roughley | O. angasi | B. haimeanus | N.S.W. (S) |
1934 | Ozaki and Ishibashi | Pinctada martensi | B. margaritae | Japan (S) |
1934 | Palombi | Tapes decussatus | Bucephalopsis haimeana 6 | Naples (S) |
1934 | Palombi | Tapes aureus | B. haimeana 6 | Naples (S) |
1934 | Wesenberg-Lund | — | Bucephalus polymorphus | Europe (F) |
1935 | Cole | Mytilus edulis | B. mytili | England (S) |
1936 | Woodhead | A. grandis | C. argi | Michigan (F) |
1936 | Woodhead | Lampsilis siliquoidea | C. basi 5 | Michigan (F) |
1936 | Woodhead | Eurynia iris | C. scioti | Michigan (F) |
1939 | Rees | Cardium edule | B. haimeanus | England (S) |
1949 | Andreu | Tapes aureus | Bucephalopsis haimeana 6 | Spain (S) |
1952 | Chubrik | Mytilus latus | Prosorhynchus squamatus 7 | Arctic? (S) |
1952 | Kniskern | L. siliquoidea | Rhipidocotyle septpapillata 8 | Michigan (F) |
1954? | Ozaki | ? | Bucephalus itabo? | Japan (S) |
1954 | Hopkins | Crassostrea virginica | B. cuculus | U.S.A. (S) |
1956 | Cable | Donax denticulatus | C. caribbea XLII | Puerto Rico (S) |
1956 | Cable | Tellina lintea | C. caribbea XLII | Puerto Rico (S) |
1958 | Hopkins | Donax variabilis | B. loeschi | Mustang Is. (S) |
1960 | Ozaki | Caecella chinensis | P. caecellae | Japan (S) |
1960 | Ozaki | Gryphaea gigas | P. magakii | Japan (S) |
1961 | Angel | Velesunionis ambiguus | C. velesunionis | Australia (F) |
1961 | Holliman | Mulinia lateralis | C. apalachiensis | Florida (S) |
1961 | Laird | Ostrea belcheri | unidentified sp. | Pakistan (S) |
F | Fresh water species. |
S | Marine species. |
1 | Considered as synonyms of B. polymorphus.page 18 |
2 | Synonymous with B. cuculus |
3 | ≡ B. haimeanus of Sinitzin, 1909. |
4 | Now R. papillosum |
5 | Synonymous with R. septpapillata |
6 | ≡ Bucephalopsis haimeanus |
7 | Adult status not determined experimentally but based on morphological resemblances. |
8 | Adult status determined experimentally. |