Boletín de la RSEHN. Sección Biológica

Se han estudiado los protozoos ciliados endobiontes de la lombriz Eisenia fetida, de un criadero natural cerca de Santiago de Compostela (España), identificándose cuatro especies de los géneros Anoplophrya y Metaradiophrya (orden Astomatida). Este trabajo constituye la primera mención de dichas especies en España. Anoplophrya lumbrici es ovoide con extremo anterior apuntado y posterior redondeado (longitud: 70-135 μm; anchura: 35- 77), con unas 51 cinetias a cada lado, y 2-5 grandes vacuolas contráctiles. Se observó en la molleja e intestino anterior y medio de la lombriz. Anoplophrya vulgaris es la especie mas abundante, con cuerpo cilíndrico (longitud: 75-150 μm; anchura: 34-75), unas 55 cinetias en cada cara, y vacuolas contráctiles más pequeñas y numerosas que en A. lumbrici. Mostró la misma distribución en E. fetida que A. lumbrici. Metaradiophrya lumbrici tiene un cuerpo rectangular (longitud 103-204 μm; anchura 69-93 μm), con un aparato de fijación constituido por un gancho externo y una rama interna situado en su extremo anterior, 83 cinetias dorsales y 54 ventrales, y 5-12 vacuolas dispuestas en dos hileras. Se encontró en la parte anterior e intermedia del intestino. Metaradiophrya varians (longitud 98-203 μm; anchura 60-115 μm) es similar a M. lumbrici pero su aparato de fijación tiene dos ramas internas, una derecha gruesa y una izquierda en forma de aguja. Muestra 80 cinetias dorsales y 46 ventrales, y 6-15 vacuolas contráctiles. Su distribución en el hospedador es similar a la de M. lumbrici.

We studied the endobiont ciliate community of the earthworm Eisenia fetida collected from a natural hatchery of O Castiñeiriño, near Santiago de Compostela (Spain). Four endobiont species of ciliates belonging to the order Astomatida were found: Anoplophrya lumbrici (Fig. 1-1), A. vulgaris (Fig.1-2), Metaradiophrya lumbrici (Fig.1-3) and M. varians (Fig. 1-4). The morphological and biometrical characteristics of these endobiont species are provided (Table I), as well as their distribution in the host gut. This is the first description of these species in Spain. Anoplophrya lumbrici (Plate I, fig.1-5) showed ovoid shape with pointed anterior end, rounded posterior end and curved lateral edges (length: 70-135 μm; width: 35-77). About 51 kineties were counted on each side (Table I). The macronucleus was ribbon-shaped and the small micronucleus was located opposite to a longitudinal row of 2-5 big contractile vacuoles. An opaque material was found in the cytoplasm of A. lumbrici (Plate I, fig 5), and some specimens contained huge accumulations of bacteria. A. lumbrici was observed in the gizzard, anterior and medium intestine of the earthworm. Anoplophrya vulgaris (Plate II, fig. 1-4) was the most abundant species. The body was cylindrical, with rounded anterior and posterior ends and parallel lateral edges (length 75-150 μm and width 34-75 μm). About 55 kineties were counted on each side (Table I). The macronucleus and micronucleus are similar to A. lumbrici. Contractile vacuoles were smaller than those of A. lumbrici, and formed generally a longitudinal row of 4-7 elements or showed different arrangements (Plate II, fig. 2-4). A. vulgaris showed the same distribution as A. lumbrici in the digestive tract of E. fetida. Metaradiophrya lumbrici (Plate II. Fig. 5-6, Plate III, fig. 1) was rectangular in shape, with a pointed anterior end that lodged the typical genus attachment apparatus: an external hook and one or two internal branches. M. lumbrici showed only one internal branch oriented towards the right side.. Length was 103-204 μm and width 69-93 μm. Specimens showed 83 dorsal and 54 ventral kineties (Table I). The macronucleus was ribbon-shaped and the micronucleus was close to it. Contractile vacuoles (5-12) were disposed in two longitudinal rows on each side of the macronucleus. M. lumbrici was found in the anterior and intermediate parts of the intestine. Metaradiophrya varians (Plate III, fig. 2-5) was similar to M. lumbrici in shape and size but showed an attachment apparatus with external hook and two internal branches, a main right branch and a very thin needle-shaped branch oriented towards the left side. Length was 98-203 μm and width 60-115 μm. Specimens showed 80 dorsal and 46 ventral kineties (Table I). Contractile vacuoles had the same distribution as in M. lumbrici but were more numerous (6-15). The distribution in the host was the same as that of M. lumbrici. We have found no evidence of encystment in each of the four species.