Dentitheca habereri ( Stechow, 1909 )

Galea, Horia R. & Maggioni, Davide, 2020, Plumularioid hydroids (Cnidaria: Hydrozoa) from off New Caledonia collected during KANACONO and KANADEEP expeditions of the French Tropical Deep-Sea Benthos Program, European Journal of Taxonomy 708, pp. 1-58 : 14-15

Dentitheca habereri ( Stechow, 1909)

Fig. 6D

Plumularia habereri Stechow, 1909: 77 , pl. 6 fig. 4.

Plumularia habereri var. attenuata Billard, 1913: 42 , fig. 34.

Plumularia habereri var. mucronata Billard, 1913: 46 , fig. 40, pl. 2 fig. 24.

Dentitheca habereri – Stechow 1920: 33; 1923a: 18; 1923b: 227. — Yamada 1959: 80. — Hirohito 1969: 25; 1974: 66; 1995: 259, fig 87a–c. — Kirkendale & Calder 2003: 167.

Dentitheca dendritica – Nutting 1927: 224 [non Dentitheca dendritica ( Nutting, 1900) ].

Plumularia habereri – Bedot 1921a: 27. — Stechow 1913: 91, figs 59–60. — Ryland & Gibbons 1991: 532, fig. 5. — Ruthensteiner et al. 2008: 20. — Ansín Agís et al. 2014: 806, figs 9–13. — Tseng et al. 2014: 3–5. — Schuchert 2015: 349, fig. 22.

Plumularia habereri var. attenuata – Bedot 1921a: 27.

Plumularia habereri attenuata – Van Praët 1979: 923.

Plumularia habereri var. mucronata – Bedot 1921a: 27.

Plumularia sp. – Inaba 1892: 350, figs 8–10.

non Plumularia habereri – van Gemerden-Hoogeveen 1965: 60, figs 34–36 [= Dentitheca dendritica ( Nutting, 1900)]. — Schuchert 2003: 211, fig. 60 [= Dentitheca elongata ( Billard, 1913) ].

non Dentitheca habereri – Di Camillo et al. 2010: 4, figs 2–3 [= Dentitheca elongata ( Billard, 1913) ].

non Plumularia habereri var. elongata Billard, 1913: 44 , figs 25–27 [= Dentitheca elongata ( Billard, 1913)].

non Plumularia habereri var. mediolineata Billard, 1913: 45 , fig. 39 [= Dentitheca elongata ( Billard, 1913)].

non Plumularia habereri var. subarmata Billard, 1913: 45 , fig. 38 [= Dentitheca elongata ( Billard, 1913)].

Material examined

PACIFIC OCEAN • 1 ca 11 cm high, sterile colony; off New Caledonia, stn DW4775; 23°03′ S, 168°17′ E; 140–277 m; 28 Aug. 2016; KANACONO leg.; barcode identifier MT655145 ; MNHN-IK-2015-573 • 1 ca 10.5 cm high, sterile colony; off New Caledonia, stn DW4743; 22°52′ S, 167°34′ E; 380– 340 m; 23 Aug. 2016; KANACONO leg.; MNHN-IK-2015-574 • 1 ca 16 cm high, sterile colony; off New Caledonia, stn DW4741; 22°52′ S, 167°41′ E; 210– 210 m; 23 Aug. 2016; KANACONO leg.; MNHN-IK-2015-575 • 3 sterile colonies, 16, 18 and 35 cm high; off New Caledonia, stn DW4727; 22°41′ S, 167°02′ E; 120–129 m; 20 Aug. 2016; KANACONO leg.; MNHN-IK-2015-577 • a 5.5 cm high, sterile colony; off New Caledonia, stn CP4786; 22°46′ S, 167°42′ E; 350–469 m; 29 Aug. 2016; KANACONO leg.; MNHN-IK-2015-591 .

Remarks

A recent, comprehensive account is given by Ansín Agís et al. (2014). Despite their opinion, this species is here reassigned to Dentitheca on the account of the emarginated hydrothecal rim on the adaxial side, creating two latero-posterior, triangular lobes, and the morphology of its gonothecae, as noted above under D. contraria comb. nov.

The Philippines record by Nutting (1927, as Plumularia dendritica ), very likely belongs to the present species. Despite Nutting’ statement that his material agrees “very exactly with the original descriptions and figures, and a comparison with the type specimens in the museum of the State University of Iowa confirms this view”, it is believed that this author was mistaken by some obvious similarities between the hydrothecae of these two species. Indeed, upon a close examination, it appears that the hydrothecal rim of D. dendritica has a pair of distinct, lateral cusps before the adaxial emargination, while the adaxial wall of D. habereri produces comparatively less marked cusps (compare Galea (2010: fig. 7d–e) with Fig. 6D herein). It is very unlikely that a common species of the tropical western Atlantic occurs in the tropical western Pacific as well, and no subsequent records of D. dendritica have been reported from this area.

Distribution

Indonesia ( Billard 1913), Japan ( Hirohito 1995), Taiwan ( Tseng et al. 2014), Philippines ( Nutting 1927, as Plumularia dendritica ; Ansín Agís et al. 2014, as P. habereri ), Coral sea off New Caledonia ( Ansín Agís et al. 2014; present study); Fiji ( Ryland & Gibbons 1991), Guam ( Kirkendale & Calder 2003).

Figures

Fig. 6. A–B. Dentitheca contraria (AnsínAgís et al., 2014), portion of cladium (A) from sample MNHN- IK-2015-582, and comparison with its counterpart of Dentitheca elongata (Billard, 1913), sample HRG- 1236 (C); gonotheca with female medusoid (B), from sample MNHN-IK-2015-585. — D. Dentitheca habereri (Stechow, 1909), portion of monosiphonic stem with three cladial apophyses and proximalmost part of a cladium, from sample MNHN-IK-2015-573. Scale bars: A, C–D = 300 µm; B = 200 µm.