Stenostomum paraguayense ( Martin, 1908 ) Luther, 1908

Reyes, Jhoe, Binow, Daniela, Vianna, Rogério T., Brusa, Francisco & Martins, Samantha E., 2021, Fig. 12. Majella pristis n in Periclimenaeus djiboutensis Bruce 1970, Zoological Studies 60 (22), pp. 1-33 : 7

Stenostomum paraguayense ( Martin, 1908) Luther, 1908 ( Fig. 2H )

Synonym: Weldonia parayguensis Martin, 1908 .

Stenostomum parayguensis ( Martin, 1908) .

Studied material: Three individuals observed, two whole-mounted individuals studied.

Localities: Site 2 (9/10/2018; 30/11/2018), associated with phytal microhabitat.

Description: Animals are elongated, live specimens are whitish. Body with 2–4 zooids. The body length is 931.5 ± 144.1 μm (829.6–1033.4 μm; n = 2) long and 115 ± 24.9 μm (97.4–132.6 μm; n = 2) wide. This species is easily recognizable due to the three pairs of light-refracting bodies, the transverse cells line with refringent granules located at the first third of the intestine, and the two caudal finger-like extensions (the dorsal extension longer than the ventral) ( Fig. 2H ).

Taxonomic remarks: Our individuals are longer than those described by Marcus (1945b) (first zooid: 350–800 μm), Noreña et al. (2005b) (first zooid: 800 μm) and Damborenea et al. (2011) (first zooid: ~680 μm). Moreover, individuals from the ESEC Taim have the dorsal caudal extension longer than the ventral, while Noreña et al. (2005b) indicate otherwise. The dorsal caudal extension could be absent or reduced as Marcus (1945b) noted. Also, the transverse cells line with refringent granules could be a variable feature since Damborenea et al. (2011) were not able to observe this feature in individuals from Peru.

Distribution: Suriname ( Van der Land 1970), Brazil ( Marcus 1945b), Peru ( Noreña et al. 2006b; Damborenea et al. 2011), Paraguay ( Martin 1908) and Argentina ( Noreña et al. 2005b).

Figures

Fig. 2. Live specimens of Catenulida. (A) Catenula lemnae, chain two zooids. (B–D) Myostenostomum vanderlandi: (B) habitus of whole-mounted individual, (C) detail of the anterior brain lobe and (D) detail of the posterior brain lobe. (E–F) Stenostomum glandulosum: (E) live individual, (F) free-hand schematic representation. (G) Stenostomum grande, a single zooid. (H) Stenostomum paraguayense, intestine with some food items. (I) Stenostomum hemisphericum, free-hand schematic representation.