Macvicaria Gibson & Bray, 1982

Aken'Ova, Thelma, Cribb, Thomas & Bray, Rodney, 2008, Eight new species of Macvicaria Gibson and Bray, 1982 (Digenea: Opecoelidae) from temperate marine fishes of Australia, ZooKeys 1, pp. 23-58 : 25-27

Genus Macvicaria Gibson & Bray, 1982

urn:lsid:zoobank.org:act:1B181DB5-4D60-4744-9520-730FD9B6AAB0

(syn. Cryptacetabulum Shalaby & Hassanine, 1997 )

Species of Macvicaria have been separated into five morphological groups, A to E, based on the distribution of vitelline follicles, the size of the cirrus-sac and the arrangement of the testes. It should be pointed out that it is diffi cult to assign some species to a particular group, so considerable care should be taken when using these groups. A sixth group, F, comprises worms of unresolved status. All new combinations were originally in Plagioporus .

Group A. Species with lateral vitelline fields continuous in the ventral sucker area, oblique to tandem testes and cirrus-sac not normally extending posterior to the ventral sucker: Macvicaria alacris (Looss, 1901) Gibson & Bray, 1982 ; M. soleae ( Nicoll, 1910) Gibson & Bray, 1982 ; M. microtestis Zdzitowiecki & Cielecka, 1997 ; M. oligolecithosus ( Wang, Wang & Zhang, 1992) n. comb.

Comment: Nicoll (1910) figured and described M. alacris and M. soleae as having oblique testes; Gibson & Bray (1982) figured them with tandem testes.

Group B. Species with lateral vitelline fields continuous in the ventral sucker area, tandem testes and a cirrus-sac usually not extending posterior to the ventral sucker: Macvicaria aegyptensis ( Shalaby & Hassanine, 1997) Cribb, 2005 ; M. crassigula ( Linton, 1910) Bartoli, Bray & Gibson, 1989 ; M. cynoglossi ( Madhavi, 1975) Bray, 1990 ; M. chrysophrys ( Nagaty & Abdel Aal, 1969) Bray, 1985 (syn: Plagioporus saoudi Ramadan, 1985 ); M. dactylopagri ( Manter, 1954) n. comb.; M. dubia (Stossich, 1905) Bartoli, Bray & Gibson, 1989 ; M. eleuthoronemae ( Wang, Wang & Zhang, 1992) n. comb.; M. longicauda ( Hafeezullah, 1971) Bijukumar, 1997 ; M. maillardi Bartoli, Bray & Gibson, 1989 ; M. mormyri (Stossich, 1885) Bartoli, Gibson & Bray, 1993 ; M. obovata (Molin, 1859) Bartoli, Bray & Gibson, 1989 ; M. ophthalmolyci Zdzitowiecki, 1990 ; M. sillagonis ( Yamaguti, 1938) Bray, 1985 ; M. taksengi Bray, 1985 ; M. hunghuaensis (Qiu & Li in Shen & Qiu, 1995) n. comb.

Comments: M. cynoglossi has obliquely tandem to tandem testes and can be accommodated in either Group A or B.

Although the cirrus-sac in M. ophthalmolyci extends posterior to the ventral sucker, we have not placed it in Group C because its cirrus-sac does not extend appreciably beyond the posterior margin of this sucker, as in the worms in the Group C, and because its general body form is different from the worms in Group C.

Macvicaria cynoglossi , M. ophthalmolyci , and M. dactylopagri can be distinguished from all the other worms in Group B as follows: M. cynoglossi has lobed testes, M. ophthalmolyci has the shortest forebody and the largest ventral sucker, and M. dactylopagri has the smallest post-testicular space, the largest oral sucker relative to the ventral sucker, and a genital pore which is closest to the anterior end.

Group C. Species with continuous lateral vitelline fields in the ventral sucker area, tandem to oblique or oblique testes and a cirrus-sac extending posterior to the ventral sucker: Macvicaria jagannathi ( Gupta & Singh, 1985) Bijukumar, 1997 ; M. longibursata Zdzitowiecki & Cielecka, 1997 ; M. longisaccus ( Fischthal & Kuntz, 1964) Bray, 1985 ; M. deeghaensis ( Gupta & Gupta, 1988) n. comb.; M. gerridis ( Fischthal & Thomas 1970) n. comb.; M. longicirrata ( Manter, 1963) n. comb.; M. skorai Zdzitowiecki, 1999 ; M. synagris ( Yamaguti, 1952) n. comb.

Comments: Gibson & Bray (1982) remarked on the close resemblance of Plagioporus gerridis Fischthal & Thomas, 1972 to Pachycreadium Manter, 1954 . This worm does not appear to conform to Manter’s (1954) concept of the genus in relation to the position of the genital pore, which Manter said was median or sub-median, or with Manter’s (1940) figure (as Plagioporus gastrocotylus ) and Yamaguti’s (1971) figure of the type-species Pachycreadium gastrocotylum Manter, 1940 , which showed that the vitelline fields were separate in the forebody, dorsally and ventrally. The definition of Pachycreadium in Bartoli, Gibson & Bray (1988) addressed these two points, among others, thereby excluding Plagioporus gerridis from Pachycreadium . In the light of this development, we propose the new combination M. gerridis for Plagioporus gerridis , which we have placed in Group C. The paratype of P. gerridis (USPC Coll. No. 70680) that we examined did not show the type of vitelline distribution figured and described by Fischthal & Thomas (1972). In the paratype, the vitelline follicles do not extend into the forebody as they do normally in species of Macvicaria . However, it is possible that the figure of this species was drawn from the holotype and that the vitelline distribution we observed in the paratype is a variant of the type figured by Fischthal & Thomas. The holotype was not available for study.

Bray (1985) remarked on the similarity of Plagioporus longicirratus Manter, 1963 to Gaevskayatrema spp. except in its having vitelline follicles which extended posterior to the testes. He suggested that P. longicirratus might be congeneric with P. synagris Yamaguti, 1952 . We have compared the measurements and descriptions of the two worms and found them to be different. P. longicirratus is a more elongate worm with a width to length ratio of 1:3.64 versus 1: 2.7 in P. synagris ; it has a smaller ventral sucker with a sucker width ratio of 1:1.18-1.2 versus 1:2.5, a smaller pharynx, with a pharynx to oral sucker width ratio of 1:1.7 versus 1:1.5, a longer forebody of 41.5% versus 29.2% of body-length, a smaller post-testicular space 6.7% versus 16.7% of body-length, longer eggs 72-73 versus 57-66 and a more posteriorly located genital pore 27.4% versus 13.2% of body-length from anterior extremity in P. synagris . On the basis of our observations we conclude that these two worms are distinct. The vitelline follicles of P. longicirratus extend posterior to the posterior testis, so, it does not fit into Gaevskayatrema Gibson & Bray, 1982 ( Gibson & Bray, 1982; Cribb, 2005). We have transferred the two species to Macvicaria and included them in Group C.

Group D. Species with vitelline follicles interrupted bilaterally in the ventral sucker region, tandem testes and a cirrus-sac not extending posterior to the ventral sucker: Macvicaria antarctica (Kovaljova & Gaevskaya, 1974) Zdzitowiecki, 1990 ; M. georgiana (Kovaljova & Gaevskaja, 1974) Zdzitowiecki, Pisano & Vacchi, 1992; M. heronensis Bray & Cribb, 1989 ; M. issaitschikowi ( Layman, 1930) Bray, 1985 ; M. muraenolepidis Zdzitowiecki, 1990 ; M. selachophidii Reimer, 1987 .

Comments: Macvicaria selacophidii was figured and described by Reimer (1987) from a single specimen with no clear indication of the anterior limit of the vitelline follicles. It is not certain if this worm belongs in Macvicaria , but we have placed it with other species in Group D because it shares some of their characteristics and also because we have observed variations within a single species of Macvicaria that include the absence of vitelline follicles from the forebody. Bray & Cribb (1989) remarked that this worm was probably a species of Allopodocotyle Pritchard, 1966 because the vitelline follicles are posterior to the ventral sucker, we share their view, however, any conclusive remarks should await examination of more specimens. No other author appears to have commented on the status of this species.

Group E. Species with vitelline follicles bilaterally interrupted in the ventral sucker area, oblique testes and a cirrus-sac usually not extending posterior to the ventral sucker: Macvicaria dampieri Bray, 1990 ; M. japonica ( Yamaguti, 1938) Bray & Cribb, 1989 ; M. macassarensis ( Yamaguti, 1952) Bray & Cribb, 1989 ; M. pennelli (Leiper & Atkinson 1914) Zdzitowiecki, 1987 ; M. branchiostegi ( Yamaguti, 1937) Bray, 1990 .

Comments: M. pennelli was figured and described as having oblique testes by Gibson (1976) and oblique or tandem testes by Zdzitowiecki (1990) and Zdzitowiecki et al. (1992). Gibson (1976) described the cirrus-sac as reaching posteriorly to a level between middle and posterior margin of the ventral sucker; Zdzitowiecki (1990) made the same observation and mentioned that the cirrus-sac sometimes extended posterior to the posterior margin of the ventral sucker. The distribution of the vitelline follicles in this worm varies; the lateral fields may be continuous, as figured by Gibson (1976), or may be interrupted, as figured by Zdzitowiecki (1990) who observed both conditions in his material.

Yamaguti (1937) described the vitelline follicles in M. branchiostegi as surrounding the posterior portion of the oesophagus and entire length of the intestine. There is a slight indication of lateral interruption in the area of the ventral sucker in his figure. For this reason, we have placed this worm in the same group as other species whose lateral vitelline fields are interrupted in the area of the ventral sucker (Group E).

Group F. Species of Plagioporus (sensu lato) which conform with Gibson & Bray’s (1982) definition of Macvicaria in every way except in their very tiny eggs; P. interruptus Manter, 1954 ; and in the distribution of vitelline follicles; P. (Plagioporus) kyusen Yamaguti, 1959 ; and Plagioporus sp. of Al-Yamani & Nahhas (1981). Bray (1985) remarked that the latter form resembled Macvicaria but refrained from transferring it to this genus, suggesting that it required further study before a definite decision can be made regarding its status.