Themiste (Themiste) hennahi Gray, 1828

Silva-Morales, Itzahí & Gómez-Vásquez, Julio D., 2021, First records and two new species of sipunculans (Sipuncula) from the Southern Mexican Pacific, European Journal of Taxonomy 740 (1), pp. 77-117 : 86-88

Themiste (Themiste) hennahi Gray, 1828

Fig. 5

Themiste hennahi Gray, 1828: 8 , pl. 6, fig. 4–4a (type locality: Peru). Dendrostoma zostericola Chamberlin, 1920: 30 (type locality: Laguna Beach, California). Dendrostomum schmitti Fisher, 1952: 422 , fig. 87f (type locality: Independencia Bay, Peru).

Dendrostoma zostericola – Fisher 1952: 411–415, fig. 87a, pl. 30, fig. 1, pls 31–32 (Ensenada, Baja California, Mexico).

Material examined

MEXICO • 1; Oaxaca, San Agustín Bay; 15°41′21″ N, 96°14′11″ W; 10 Feb. 2007; depth 2 m, in Porites ; UMAR-SIPU 103 .

Description

Specimen damaged. Trunk white in color, 15 mm in length ( Fig. 5A ). Introvert 5 mm in length, without hooks or pigmented collar. Tentacular crown with four asymmetrical stems, giving appearance of six primary stems ( Fig. 5B ). Peripheral tentacles with pigment spots. Longitudinal muscle of body wall gathered in uniform continuous layer. Nephridiopores opening at level of anus. A pair of retractor muscles attached to body wall at 75% of trunk length ( Fig. 5C ). Five tubular extensions, very fragile (not illustrated but observed).

Remarks

The type locality from Themiste hennahi is Peru. Unfortunately, Gray (1828) did not specify the locality. The species has also been recorded from Laguna Beach, Southern California, and Ensenada, Baja California ( Fisher 1952), under different names ( Cutler 1994). We advise the revision of the specimens from the Subtropical Eastern Pacific to confirm the widespread distribution of T. hennahi .

Habitat

Subtidal (2 m); in dead coral ( Porites ).

Distribution

Southern California, Baja California and Tropical Eastern Pacific (Oaxaca and Peru).

Figures

Fig. 5. Themiste (Themiste) hennahi Gray, 1828 from Oaxaca, Mexico. A. External morphology. B. Tentacular crown. C. Internal morphology. Abbreviations: I = intestine; LM = longitudinal muscle; N = nephridium; RM = retractor muscles.