Billibathynella wolframnoodti, Hong & Cho, 2009

Hong, Sungwon J. & Cho, Joo-Lae, 2009, Three new species of Billibathynella from Western Australia (Crustacea, Syncarida, Parabathynellidae), Journal of Natural History 43 (37 - 38), pp. 2365-2390 : 2366-2373

publication ID	https://doi.org/ 10.1080/00222930903108702
persistent identifier	https://treatment.plazi.org/id/9911D173-FF9E-FFE4-FE28-8DCA6E4A7216
treatment provided by	Felipe
scientific name	Billibathynella wolframnoodti
status	sp. nov.

Treatment

Billibathynella wolframnoodti sp. nov.

( Figures 1–5 View Figure 1 View Figure 2 View Figure 3 View Figure 4 View Figure 5 )

Etymology

The specific epithet is derived from the late Prof. Dr Wolfram Noodt (Kiel, Germany), who initiated bathynellacean study.

Type material

Holotype. Male, dissected on eight slides. Australia, Western Australia, Gascoyne, Neds Creek Station , Esso seismic uphole site 189 (25°40′14′′ S, 119°46′19′′ E), BES 10150, 24 August 2005, (W.F. Humphreys and J.M. Waldock) ( WAM C 40057). GoogleMaps

Allotype. Female, dissected on two slides, same data as of holotype ( WAM C 40058).

Paratypes. Two males, each kept as a whole specimen on a slide ( WAM C 40059 – C 40060) .

Description of adult male (holotype)

Body ( Figure 1A View Figure 1 ). Elongated and cylindrical, length 5.12 mm (other males: 4.64, 4.56), approximately 10 times as long as wide. Head as long as anterior three thoracic segments combined.

Antennule ( Figure 1B View Figure 1 ). Seven-segmented. First segment with one seta on inner distal margin, three simple dorsal setae, and one dorsal, one ventromedial and two lateral plumose setae. Second segment with one group of four plumose setae and eight simple setae on inner margin. Third segment with three lateral setae including one plumose seta and eleven setae on inner margin. Inner flagellum of third segment with three simple setae. Fourth segment with one stub seta and one plumose seta on dorsal margin, and two stub setae and two plumose setae on outer distal apophysis. Fifth segment with one dorsal seta and six setae on inner margin. Sixth segment with one aesthetasc, one seta, and two aesthetascs dorsally, and with five setae on inner margin. Seventh segment with three aesthetascs and four simple setae.

Antenna ( Figure 1C View Figure 1 ). Seven-segmented, as long as the length of antennular segments 1–4. Setal formula: 0+0/0+0/1+1/2+1/0+0/3+2/4(1).

Labrum ( Figure 1D View Figure 1 ). Flat with 12 teeth of similar size flanked by five teeth decreasing in size laterally on both lateral sides. Inner surface with numerous rows of ctenidia and a few nipple-like protrusions.

Mandible ( Figure 1E,F View Figure 1 ). With incisor process of six teeth. Tooth of ventral edge triangular. Spine row consisting of 14 spines. Palp of one segment, with one apical seta.

Maxillule ( Figure 1G View Figure 1 ). Two-segmented. Proximal segment with four setae on inner distal margin. Distal segment with two terminal spines, one large most distal spine

and six spines on inner edge, and three simple setae on outer distal margin. The most distal spine of distal segment slightly longer than the other spines.

Maxilla ( Figure 1G View Figure 1 ). Four-segmented, setal formula 5-9-21-15.

Thoracopods. Thoracopods I–IV ( Figures 3A–C View Figure 3 , 4A View Figure 4 ) increasing in size posteriorly. Thoracopods IV–VII ( Figures 4A,B View Figure 4 , 5A,B View Figure 5 ) similar in size. Thoracopods I–VII each bearing one small epipod on protopod and one seta on basipod. Number of segments of exopods of thoracopods I–VII: 8-11-12-12-12-13-12. All the thoracopods with two setae in each segment of the exopod, except on the first segment where they have three or four setae. Endopod of thoracopods I–VII four-segmented, setal formulae given in Table 1. Thoracopod VIII ( Figure 2A,B View Figure 2 ) more or less rectangular in frontal view, twice as long as wide. Protopod massive, with prominent penial region with a distal opening. Epipod large, triangular, its distal part reaching the penial region of the protopod. Basipod without setae, inner margin of basipod drawn out into projection. Exopod ( Figure 2C View Figure 2 ) one-third size of basipod, triangular, dentate distally, bearing three subterminal setae. Endopod half as large as exopod, with two distal setae.

First pleopod ( Figure 4C View Figure 4 ). In form of two stubs being distanced from each other basally. Each stub bearing two distal setae of different size.

Uropod ( Figure 2G,F View Figure 2 ). Sympod five times longer than wide, bearing 25 spines of similar size on inner margin that occupy two-thirds of its length. Endopod ( Figure 2G,F,I View Figure 2 ) 50% as long as sympod, with two dorsal plumose setae near the base, three terminal setae on outer distal margin, one dorsal subterminal plumose seta; one distal and one subterminal spine similar in size, five times longer and thicker than the seven additional tiny spines on the inner margin. Exopod almost 77% as long as sympod, with 17 setae on outer and terminal margin and four setae on inner margin, without basi-ventral seta.

Pleotelson ( Figure 2E,F View Figure 2 ). With one seta near the base of furcal rami on both sides. Anal operculum concave.

Furcal rami ( Figure 2E,F,H View Figure 2 ). Four times as long as width, almost as long as pleotelson, with two large distal spines and 19 thin spines on inner margin, and two dorsal plumose setae.

Description of female (allotype)

The female differs from the male as follows. Body length 4.36 mm. Setal formula of antenna: 0+0/0+0/1+1/2+1/0+0/2+2/4(1). Setal formula of maxilla: 5-7-17-15. Number of exopodal segments of thoracopods I–VII: 7-9-11-11-11-11-11. Setal formula of thoracopodal endopods is shown in Table 1. Both right and left thoracopods VIII ( Figure 2D View Figure 2 ) cone-shaped, half as large as endopod of male thoracopod VIII. Uropodal sympod with 22 spines.

Variation

In two male paratypes the following variations are observed. The sixth antennal segment with four setae; the second segment of maxilla with seven setae; number of exopodal segments of thoracopods I–VII: 6-9-10-11-11-11-10. Setal formula of thoracopodal endopods is shown in Table 1. The uropod sympod with 22 to 23 spines; endopod with six spines on inner margin; exopod with 17 to 18 setae on outer and terminal margin.