Brachylaima mazzantii ( Travassos, 1927 )

Marques, Juçara de Souza, Rocha, Bárbara Marum, Manso, Pedro Paulo de Abreu & D'Ávila, Sthefane, 2017, New insights on the morphology of a digenean parasite Digenea: Brachylaimidae, Brachylaima mazzantii (Travassos, 1927 )) using confocal laser scanning microscopy, Zoosystema 39 (4), pp. 449-462 : 451-453

publication ID	https://doi.org/ 10.5252/z2017n4a1
publication LSID	urn:lsid:zoobank.org:pub:0F5D59AF-1AF2-4BD3-8C26-1198D5766D9E
persistent identifier	https://treatment.plazi.org/id/D30287C6-136A-FFBB-FF1B-5C36FE79F975
treatment provided by	Felipe
scientific name	Brachylaima mazzantii ( Travassos, 1927 )
status

Treatment

Brachylaima mazzantii ( Travassos, 1927)

Harmostomum mazzantii Travassos, 1927: 844 .

Brachylaemus (Mazzantia) mazzantii – Travassos & Khon 1966: 13.

Brachylaima mazzantii – Adriano 2001: 34-35.

SPECIMEN EXAMINED. — Host: Columbia livia Gmelin, 1789 ( Aves View in CoL , Columbidae View in CoL ). Locality: Juiz de Fora, Minas Gerais, Brazil.

The helminths were obtained from the helminthological collection of the Department of Zoology, Juiz de Fora Federal University, Minas Gerais, Brazil. The specimens, previously maintained in ethanol 70%, were prepared according to the conventional helminthological techniques, following the protocols proposed by Amato et al. (1991).

REPRODUCTIVE SYSTEM

The common opening of the reproductive system is located post-equatorial in the middle of a discrete salience ( Figs 1 View FIG A- C; 2). The genital pore is pre-testicular (anterior to the anterior testis) and surrounded by a distinct collar of gland cells ( Figs 1A, B View FIG ; 2 View FIG ). On a deeper plane, the genital pore gives place to the male and female openings ( Figs 1D View FIG ; 2A View FIG ). The reproductive system is situated post-acetabulum and intracaeca. The genital atrium wall is formed by circular muscles fibers. Several glandular cells are visible between the genital atrium wall and the wall of the genital opening, which is also formed by circular muscle fibers. These glandular cells became gradually scarce as the female and male openings became individualized ( Figs 1 View FIG A-E; 2).

MALE APPARATUS

The male genitalia contain a seminal vesicle external to the cirrus pouch, convoluted and filled with sperm. There is a thick-walled bursa that narrows distally prior to opening into an elongate cirrus pouch containing short, unarmed cirrus ( Fig.1 View FIG ). Pars prostatica was not observed. The male germinative lineage is comprised of five cell types. The spermatogonia are the largest cells, with low cytoplasmic content. The nucleus fills the greatest portion of the cell, having an intensely stained heterochromatin. Spermatids are rounded cells arranged in groups, with heterochromatic nucleus of various shapes due to morphological alterations observed during meiosis. The spermatocytes are also arranged in groups. Two stages of development were identified: primary and secondary spermatocytes. Primary spermatocytes are small rounded cells, with small rounded nucleus showing condensed chromatin. After mitotic division, the secondary spermatocytes, which are elongated cells, also arranged in groups, develop. The spermatozoa are arranged in groups and aligned; they can be recognized by its long tails arranged in parallel.

FEMALE APPARATUS

The female apparatus ( Fig. 3 View FIG ) is composed of ovary, ootype, vitelline glands and reservoir, Mehlis’ gland, seminal receptacle and uterus. The ovary lies in the region between the anterior and posterior testes ( Figs 1F View FIG ; 3B View FIG ). Mehlis’ gland surrounds the meeting point of the vitelline reservoir’s duct, oviduct, uterus and the duct that comes from the seminal receptacle ( Figs 3 View FIG ; 4A View FIG ). Laurer’s canal was not observed. The ovary is completely filled by oocytes presumably in different maturation phases because of the size differences among cells. In the posterior region of the ovary, adjacent to the oviduct, there is a round projection. At this site, the oocytes are larger and appear to be free. The oocytes are round cells of relatively small cytoplasmic volume with great central nuclei with prominent nucleoli. Vitelline glands are formed by several acini ( Figs 3 View FIG ; 4D View FIG ), and extend from the beginning of the intestinal caeca bifurcation. The mature vitellocytes have abundant cytoplasm, with numerous spherical cytoplasmic inclusions. These cells are carried through the vitelline duct forming a single row ( Fig. 4E View FIG ) and are stored in the vitelline reservoir.

The uterus ascends to the pharynx and then descends to the genital pore, occupying the body by its bending, when it is replete of eggs ( Fig. 4F View FIG ). The metraterm is prominent, muscular, straight ( Fig. 1E View FIG ). The operculate egg is protected by a shell and the embryo is surrounded by the von Lichtenberg’s envelope ( Figs 3 View FIG ; 4G View FIG ).

ALIMENTARY TRACT

The pharynx is shaped by a dense disposition of radial musculature bundles that connects the inner and outer walls ( Fig. 5C, D View FIG ). A narrow esophagus, circled by esophageal glands ( Fig. 5E View FIG ), connects the pharynx to the intestinal caeca. Covering the inner wall of the intestinal caeca there are numerous microvilli ( Fig. 5F View FIG ).

MUSCULATURE OF THE BODY WALL

The musculature of the body wall is formed by three layers, an outer layer of circular fibers, an intermediate layer of longitudinal fibers and an inner layer of diagonal fibers ( Fig. 6 View FIG C- E). The outer layer ( Fig. 6C View FIG ) appears immediately bellow the tegument covered by scales ( Fig. 6 View FIG A-C), which show a variable number of sulci ( Fig. 6B View FIG ). This is the first account for the presence of scales in the tegument of B. mazzantii . The intermediate layer is formed by dense longitudinal bundles and the inner layer is formed by a mesh of thick diagonal fibers that cross each other in a spaced way ( Fig. 6D View FIG ). Thick bundles of differentiated musculature were also seen ( Fig. 6E View FIG ), probably increasing the stability of the acetabulum ( Fig. 6G View FIG ).

ATTACHMENT APPARATUS

The oral sucker and acetabulum show a well-developed musculature. It is formed by meridional musculature ( Fig. 5A View FIG ), equatorial bundles surrounding the opening of the suckers ( Fig. 5B View FIG ), and radial musculature connecting the inner and outer surfaces of these structures ( Figs 5C View FIG ; 6G View FIG ). The main difference related to the musculature of the oral sucker and acetabulum is the disposition of the radial bundles, which are thin, densely arranged and in larger amount on the oral sucker, whereas the acetabulum has fewer, spaced and thick radial fibers. Both structures have numerous papillae in the external and internal surfaces ( Figs 5C View FIG ; 6 View FIG F-H). They were found isolated or arranged in number of three. The oral sucker and acetabulum differed in the amount of papillae, largely found on the acetabulum and noticed in a less number on the oral sucker.

EXCRETORY AND NERVOUS SYSTEM

The excretory system of B. mazzantii is represented by thin excretory ducts that run along the lateral of the body ( Fig. 7A View FIG ) and by the excretory bladder which is wide, relatively long and bullet-shaped ( Fig. 7B View FIG ). The tomographies also showed parts of the basic flatworm plan of peripheral nerve elements. A pair of ventral nerve cord ( Fig. 7C View FIG ) extends from the cerebral ganglia and ran the length of the worm till the bladder zone. Transverse connectives between the pair of nerve cords were also seen ( Figs 1B View FIG ; 7D View FIG ).