Pristina sima ( Marcus, 1944 )

Righi, Gilberto & Hamoui, Viviane, 2002, Oligochaeta, Naididae Of The West Indies And Adjacent Regions, Papéis Avulsos de Zoologia 42 (6), pp. 119-167 : 146

Pristina sima ( Marcus, 1944)

( Fig. 3 H-K)

Naidium simum Marcus, 1944: 68 , figs. 58-59.

Pristina sima, Sperber, 1948: 223 .

Pristinella sima, Brinkhurst, 1985: 472 .

(non) Pristina sima Ercolini, 1969: 26 , fig. 33; Martinez-Ansemil & Giani, 1980: 48, fig. 2; Rodriguez & Armas, 1983: 96; Varela, 1990: 224.

Material : Curaçao 74c: 4 specimens (ZU-1324). Habitat: Weakly oligohaline; salinity 0.88 %.

Distribution: Restricted to Neotropical Region: Brazil: São Paulo State

( Marcus, 1944) and Curaçao (Righi & Hamoui).

Description: Length 2.9-3.0 mm. Diameter 125-130 µm. Number of segments 30-32. Short conic prostomium. Eyes and division-zone missing. There are no septal glands. Pharynx goes to III; thin esophagus; small stomach in VIII; intestine begining at X. Dorsal vessel running along the left side from IX backwards; commissural vessels unrecognizable. All the setae begin at II dorsal bundles with 1-2 hairs and 1-2 needle setae on each. The hairs are smooth, straight, their length increases regularly from 80-202 µm in II- VI; towards the back the length varies from 129-196 µm, the shorter ones are in the last segments. The needles are 40-59 µm long, the longer ones are posterior; a small nodulus sets apart a little curved distal part shorter than the straight proximal part. The apex has two teeth of similar length, the same worm presents 0-2 intermediate denticles ( Fig. 3 H-I), usually there are only one intermediate denticle as long as the two main teeth. The ventral setae are 2-3 per bundle in II-VII and 1-2 backwards. The length of the ventral setae increases gradually from 33-57 µm in II-VII and it varies from 52-57 µm in the following segments. The setae nodulus is medial in II and distal from III onwards. The distal tooth is longer than the proximal one in II-VII ( Fig. 3J ); towards the back the two teeth have similar length ( Fig. 3K ); the proximal tooth is always thicker.

Remarks: This is the first finding of the species after the original description. The measures of the setae in our material enlarge the variability recorded to the type-material. Harman et al. (1988) interpret Pristina sima as a synonymous of Pristinella osborni , which cannot be accepted due to differences in needles and septal glands. The specimens from NE Argentina studied by Varela (1990) belong probably to Pristina notopora Cernosvitov (1937) not to P. sima as she identified on account of their serrate hairs and greater number of ventral setae. The specimens from Somalia studied by Ercolini (1969) and those of Spain studied by Martinez-Ansemil & Giani (1980) and Rodriguez & Armas (1983) differ from P. sima by the needle setae, probably they belog to P. rosea .

Figures

Fig. 3. Aulophorus barbatus: A, hair and needle. B-D, ventral setae of V, VIII and XXXV.Allonais japonica: E, needle. F-G, ventral setae of II and XII. Scale = 10 µm. Pristina sima: H-I, needles. J- K, ventral setae of IV and X. Scale = 10 µm.