Macrorhynchia philippina Kirchenpeuer, 1872

Chakraborty, Oishinee & Raghunathan, C., 2020, Notes on seven Aglaopheniids (Cnidaria: Hydrozoa: Aglaopheniidae) from Andaman and Nicobar Islands with three new records to India, Zootaxa 4790 (2), pp. 291-317 : 300-303

Macrorhynchia philippina Kirchenpeuer, 1872

( Fig. 2e , 5 a–d)

Aglaophenia philippina Kirchenpauer 1872: 45–46 , pl. 1, fig. 26, pl. 2 figs 26 a, b, pl. 7, fig. 26. Aglaophenia urens Kirchenpauer 1872: 46 , pl. 1, fig 27, pl. 2, fig. 27, pl. 7, fig. 27. Macrorhynchia philippina Kirchenpauer 1872: 19 ; Calder 1983: 23–24, fig. 13; 1986: 139–140, pl. 39; Rees & Vervoort 1987:

177–180, fig. 43; Vervoort 1987: 86; Cairns et al. 1991: 29; Ryland & Gibbons 1991: 553–555, fig. 22; Calder 1993: 68;

Vervoort, 1993: 550; Bouillon, 1995: 38; Hirohito 1995: 297–299, fig. 105d–g; Watson 1996: 97; 2000: 67– 68, fig. 53A–

D; Vervoort & Watson 2003: 336–337, fig. 81D; Di Camillo et al., 2009: 214–217, figs. 2F, 2G, 5A–5G, 8G–8I. Aglaophenia perforate Kirchenpauer 1876: 25 (not Allman 1885).

Lytocarpus philippinus Pictet 1893: 60 , pl. 3, fig. 53; Nutting 1900: 122, pl. 31, figs 4–7; Billard 1913: 78, fig. 63; Fraser 1944: 419, pl. 93, fig. 410; Vervoort 1968: 88, fig. 41; Millard & Bouillon 1973: 93; Millard 1975: 449, fig. 138A–C; Ljubenkov, 1980: 50; Boero, 1984: 99; Bouillon, 1984: 106; Russell, 1984: 105; Rho & Park 1986: 18; Bandel & Wedler, 1987: 38; Mergner, 1987: 187; Southcott, 1987: 81; Park, 1992: 296; Marsh, 1993: 22; Allen & Steene, 1994: 51; Kalk, 1995: 259, fig. 9.9a.

Lytocarpus crosslandi Ritchie, 1907: 511 , pl 24 fig 11, pl 26 figs 2–4.

Material examined. Stn. 2: 10.ix. 2017, 8 m; Stn. 4: 22.i.2017; Stn. 5: 12.ix. 2017, 9 m; Stn. 6: 21.i. 2017, 6 m; Stn. 7: 09.i. 2019, 5 m; Stn. 8: 27.v. 2017, 8 m; Stn. 9: 25.x. 2017, 9 m; Stn. 10: 14.i. 2019, 4 m; Stn. 14: 26.x. 2016, 8 m; Stn. 19: 28.x. 2016, 5 m; Stn. 21: 30.v. 2017, 6 m; Stn. 22: Craggy Island, 7 m; Stn. 23: 13.v. 2018, 4 m; Stn. 24: 14.v.2018, found on the ship hull; Stn. 26: 29.xii. 2018, 15 m; Stn. 34: 22.ii. 2017, 14 m; Stn. 35: 23.iii. 2018, 13 m; Stn. 36: 5.x. 2016, 6 m; Stn. 37: 5.viii. 2016, 10 m; Stn. 42: 22.ix. 2016, 9 m.

Description. Colonies large, highly branched with multi-pinnate polysiphonic stem with only short terminal portions being monosiphonic. Stem consisting of primary and auxillary tubes, primary tube gives rise to hydrocladia. Base of primary tube giving rise to side branches with hydrocladial apophysis, one median inferior nematotheca, one nematotheca on the side of the apophysis and a mamelon on the apophysis. Hydrocladia alternate and arranged anteriorly to the primary tube. Each hydrocladium segmented by transverse to slightly oblique nodes and two variably developed internal ribs. Hydrothecae sac-shaped, upper third curving away and opening obliquely to the hydrocladium ( Fig. 2e ). Hydrothecal margin with two rounded cusps and one abcauline tooth. Thick shelf projecting half way into the hydrotheca between the margin and the median inferior nematotheca, which appearing triangular in side view. Median inferior nematotheca tubular, appearing conical in side view and reaching beyond the hydrothecal margin. Lateral nematothecae usually inclined forward and overtopping the hydrotheca. Gonothe- cae borne on modified hydrocladia (phylactocarps) ( Fig. 5d ). Phylactocarps composed of a hydrothecate segment. Gonotheca attached to the following segment in turn followed by cylindrical segments bearing one or two nematothecae each. Gonothecae are lens-shaped.

Colour. Primary branches and side branches are brown to dark brown and hydrocladia are white ( Fig. 5a ).

Remarks. This species has been frequently encountered in Indian waters of mainland India. In Andaman and Nicobar Islands, though the species is found abundantly and photographic documentation of the species has been done (Venkatraman et al., 2012), no formal description of the species had been made. Thus, this report provides the first detailed description of the species from Andaman and Nicobar Islands showing a bathymetric range of 4 to 15 m.

Associated fauna. The growth form of the species was observed to be large, often with associated fauna such as Lomanotus vermiformis Eliot, 1908 , the nudibranch which is found exclusively on this species (Willan, 1988) ( Fig. 5c ). The bivalve Pterelectroma physoides (Lamarck, 1819) was also frequently observed attached to the hydrocaulus of the species.

Substrate. The species was observed to occur abundantly in the Islands, a specimen was collected from the hull of a ship as well. The colonies were found to be rather large and conspicuous ( Fig. 5 a–b), sheltering other faunal groups and in turn providing a micro-habitat for other animals.

Distribution. Type locality; Manila, Philippines

India; Andaman and Nicobar Islands ( Ritchie 1910a and present study), Kathiawar, Gujarat ( Thornely 1916); Gulf of Mannar ( Gravely 1927); Maharashtra ( Nagale 2013); Gulf of Kutcchh ( Nagale, 2014 a); Pamban bridge ( Mammen, 1965b)

Elsewhere; Circumglobal in tropical and subtropical waters ( Schuchert, 2003)

Figures

FIGURE 2. Illustrations of hydrothecae. a, Aglaophenia cupressina Lamouroux, 1816. b, Gymnangium hians (Busk, 1852). c, Lytocarpia brevirostris (Busk, 1852). d, Lytocarpia delicatula (Busk, 1852). e, Macrorhynchia philippina Kirchenpeuer, 1872. f, Macrorhynchia phoenicea (Busk, 1852). g, Monoserius pennarius (Linnaeus, 1758). Scale bar, a, b, g= 200µm, c, d, e, f, h, i=100µm.

FIGURE 5. Macrorhynchia philippina. a, Colony at Paget Island. b, Colony at Sir Hugh Ross Island. c, Nudibranch, Lomanotus vermiformes, on M. philippina at North Bay. d, Gonothecae on modified hydrocladia. Scale bar, d= 1mm.