Dasella ansoni Bruce, 1983

de Gier, Werner & Fransen, Charles H. J. M., 2023, Polka-dotted treasures: Revising a clade of ascidian- and bivalve-associated shrimps (Caridea: Palaemonidae), Contributions to Zoology 92 (3), pp. 179-282 : 213

Dasella ansoni Bruce, 1983

Dasella ansoni Bruce, 1983d: 22 , figs. 1–5 [Type locality: Arafura Sea, 10°58’S 132°10’E, 27 m; see Bruce & Coombes, 1995]; Berggren, 1990: 558 (listed); Bruce, 1990: 10, 16, 18 (listed); Müller, 1993: 23 (listed); Holthuis, 1993: 140, fig. 123 (listed); Bruce & Coombes, 1995: 108 (listed); Li, 2000: 41, fig. 41 (listed); De Grave & Fransen, 2011: 348 (listed).

Diagnosis (based on Bruce, 1983d). Small-sized shrimp. Rostrum barely reaching distal border of distal segment of antennular peduncle, slightly depressed, acute, dorsally thickened, without distinct lateral carinae, without dorsal teeth, with one acute minute ventral tooth near tip.Antennal spine present, small. Hepatic spine well-developed, small, mobile, below level of than antennal spine. Inferior orbital angle distinct, produced. Antero-lateral angle of carapace broadly rounded, feebly produced. Anterior margin of carapace between ventral orbital angle and antero-lateral angle straight. Sixth abdominal segment with posterolateral angle acute, posteroventral angle feebly acute. Telson with large dorsal spines at 0.35 and 0.50 of telson length, lateral pair of terminal spines just behind intermediate pair, distal margin

of telson rounded, without median process. Basal segment of antennular peduncle with one small distolateral tooth. Scaphocerite with lateral margin almost straight, slit between small distolateral tooth and lamina shallow. Chela of first pereiopods spatulate, with cutting edges minutely pectinate along entire rim. Second pereiopods unequal; almost straight dactylus barely exceeding fixed finger on both chelae, without teeth on cutting edges; palm without tympanal organ. Ambulatory dactyli with large broad distoventral process on flexor margin of corpus, accompanied by small hooked tooth on tip in third and fourth pereiopods; unguis simple, acute. Distoventral spines on ambulatory propodi long, acute.

Colour. Generally transparent; rostrum, antennular peduncles and chelae of second pereiopods feebly spotted with small white dots (Bruce, 1983d).

Hosts. Only known to be associated with one species of ascidian: Phallusia depressiuscula (Heller, 1878) ( Ascidiidae ) (Bruce, 1983d).

Distribution. Only known from its type locality: Arafura Sea (10°58’S 132°10’E), Australia (Bruce, 1983d; Bruce & Coombes, 1995).