Carcinonemertes tasmanica, Sadeghian & Santos, 2010

Sadeghian, Patricia S. & Santos, Cynthia, 2010, Two new species of Carcinonemertes (Hoplonemertea: Carcinonemertidae) living in association with leucosiid crabs from California and Tasmania, Journal of Natural History 44 (37 - 40), pp. 2395-2409 : 2402-2403

Carcinonemertes tasmanica sp. nov.

Carcinonemertes sp. B . ( Sadeghian and Kuris 2001: 59–63; fig. 1.), Carcinonemertes new species B ( Sadeghian 2003), Carcinonemertes sp. ( Bell and Hickman 1985).

Type material

Holotype. Female worm, whole animal. SBMNH 423142 .

Paratype. Female worm, whole animal. USNM 1138229 .

Type locality

Southwest Pacific Ocean, Australia, Tasmania, Hobart, Pipeclay Lagoon , 42 ◦ 57 ′ S, 147 ◦ 32 ′ E, low tide; 20% exposed; on sandy substratum .

Material examined

Seven preserved specimens of Dittosa laevis were examined and 82 preserved worms were recovered. Histological preparations were not made because of poorly preserved specimens.

Diagnosis

Sexually mature adults filiform, red, to 12 mm long. Sexes separate, males smaller than females. Stylet to approximately 7 µm long, basis ovoid, to approximately 13 µm long. Mucus sheath present, non-ornamented, with distinctive spiral or corkscrew shape. Newly hatched larvae are ovoid, covered with cilia, and measure 130 µm long and 52 µm wide.

Description

Sexually mature adult worms. Inhabit sheaths attached to setae of pleopods or abdominal surfaces of crab. Body filiform, head rounded; length of adult females from 2.3 to 12.0 mm (5.6 ± 1.3 mm; n = 20) ( Figure 4 ); adult males from 0.9 to 4.0 mm (1.9 ± 0.7 mm; n = 21). Two ocelli present. Live worms red; preserved worms white.

Sheath. Tubular, open at one end; mucoid; distinctive corkscrew shape, nonornamented; slightly longer than worm.

Proboscis complex. Bell and Hickman (1985) do not state separate measurements for the stylet and basis and further work on live animals is needed. They describe a proboscis with three distinct chambers; male stylet and basis length to 22 µm, female stylet and basis length to 19 µm. In analysing these measurements along with line art and scale bar provided by Bell and Hickman (1985), we calculate stylet length to be 6.7 µm and basis length to be 13.3 µm.

Larvae and juveniles. Bell and Hickman (1985) note that newly hatched larva ovoid and ciliated; measuring 130 by 52 µm; anterior and posterior cirri 30 µm and 20 µm long respectively; epidermis from 8 to 10 µm thick; single elongated eyespot situated anteriorly. Juveniles encapsulated in transparent mucus sheaths, attached to adjacent gill lamellae and in the branchial chamber of both male and female crabs.

Dormant adults. Unsheathed and found attached to the sternum and the ventral surface of the abdomen of non-ovigerous mature female crabs. Average length and diameter of dormant worms was 1.68 mm and 0.4 mm respectively.

Host geographic distribution

Australia; South Gulf Coast, Tasmanian Coast, Bass Strait, and South West Coast.

Etymology

This species is named after the locality from which the type specimens were collected.

Figures

Figure 4. Carcinonemertes tasmanica sp.nov.; female worm in excised egg mass. Scale bar 1 mm.