Lagenipora perplexa ( Harmer, 1957 ), 2025

Lagenipora perplexa ( Harmer, 1957) View in CoL n. comb.

( Fig. 9.1–6 View FIGURE 9 )

Lekythopora perplexa Harmer, 1957: 884 , pl. LIX, figs 5–7.

Celleporina perplexa View in CoL : Hayward 1988a: 342, pl. XV, figs (b)–(d).

Lagenicella sp. : Symphonia & Nathan 2022: fig. 5.6–7.

Material examined. SMF 40781 (St. 283 KU; Fig. 9.2, 9.5 View FIGURE 9 ), SMF 40804 (St. 283 KU; Fig. 9.3–4 View FIGURE 9 ), SMF 40805 (St. 283 KU; Fig. 9.1, 9.6 View FIGURE 9 ).

Description. Colony rigidly erect, multiserial, unilamellar, dichotomously branching, forming cylindrical branches ( Fig. 9.1 View FIGURE 9 ). Autozooids arranged in alternating series, separated by distinct furrows ( Fig. 9.2 View FIGURE 9 ). Ancestrula autozooidal, with salient, peristomate orifice and reduced frontal shield ( Fig. 9.3 View FIGURE 9 ).

Autozooids oblong to narrowing proximally to slightly hexagonal, 448–699 μm (ẋ = 603 ± 66 µm; CV = 11; N = 26 on 3 specimens) long by 152–268 μm (ẋ = 221 ± 29 µm; CV = 13; N = 26 on 3 specimens) wide, inclined outwardly in ovicellate autozooids at about mid-length, while entirely horizontal in infertile autozooids ( Fig. 9.4, 9.6 View FIGURE 9 ). Frontal shield slightly convex, pierced by up to 20 circular pores all around the margins and occasionally with few circular pores centrally, smooth, traversed by several depressions starting from the pores and progressing to the centre. Primary orifice circular. Peristome terminal, prominent, cylindrical. Secondary orifice circular, 75–165 μm (ẋ = 116 ± 20 µm; CV = 17; N = 19 on 3 specimens) long by 100–152 μm (ẋ = 118 ± 15 µm; CV = 13; N = 19 on 3 specimens) wide. Spine bases not observed. Ovicells on distal peristomial rim, oblate spheroid, 72–96 μm (ẋ = 87 ± 7 µm; CV = 8; N = 11 on 3 specimens) long by 122–170 μm (ẋ = 150 ± 14 µm; CV = 9; N = 11 on 3 specimens) wide, supposedly opening in to base of peristome; ectooecia incompletely calcified, smooth, leaving rectangular window proximally and centrally; endooecia smooth, imperforate ( Fig. 9.5 View FIGURE 9 ) .

Avicularia possibly paired at lateral margins of secondary orifice ( Fig. 9.6 View FIGURE 9 ).

Kenozooids interzooidal, polymorphous, frequently found at colony base in ancestrular region ( Fig. 9.1, 9.3 View FIGURE 9 ). Kenozooidal cryptocyst infrequently pierced by circular to elliptical pores.

Remarks. Lagenipora perplexa n. comb. is an enigmatic species that had originally been described by Harmer (1957) from the Timor Sea northwest of Jaco, Timor-Leste. The specimens from the Gulf of Aden attributed to this species closely resemble those imaged by Hayward (1988a) from Mauritius and Symphonia & Nathan (2022) from the Bay of Bengal (as Lagenicella sp. ). Harmer’s original material, however, has not been adequately illustrated and has not been formally revised. A direct comparison with the Timor specimens is therefore not feasible, and our identification of Lagenipora perplexa n. comb. is based entirely on the specimens described by Hayward (1988a).

The Gulf of Aden material consists of several young, erect, branching colonies composed of cylindrical internodes formed by whorls of up to six autozooids. Notably, the ancestrular region that was previously unreported for this species is well-preserved in the Gulf of Aden specimens. A distinctive dimorphism is observed between fertile and infertile autozooids in Lagenipora perplexa n. comb. Infertile autozooids possess a short peristome surrounding the terminal primary orifice ( Fig. 9.4 View FIGURE 9 ), while ovicellate zooids exhibit a slight outward inclination at mid-length ( Fig. 9.6 View FIGURE 9 ). An ovicell is wedged between the raised, cylindrical portion of the autozooid and subsequent autozooids ( Fig. 9.5 View FIGURE 9 ). Although the ovicell opening was not directly observed, it is presumed to open within the proximal portion of the peristome.

Lagenipora perplexa View in CoL n. comb. had previously been assigned to Celleporina Gray, 1848 View in CoL by Cook & Hayward (1983). However, Hayward (1988a) already pointed out key differences from true Celleporina View in CoL species, including the erect, regularly branching colony form, distinct ovicell morphology, the configuration of the primary orifice, and the absence of vicarious avicularia. Upon comparison with the type species Lagenipora lepralioides ( Norman, 1868) View in CoL , an encrusting species originally reported from the coasts of the Shetland Islands, United Kingdom, the Indian Ocean species are here reassigned to Lagenipora View in CoL . This placement is supported by similarities in ovicell structure and frontal shield morphology. In particular, the ancestrular region in the Gulf of Aden specimens ( Fig. 9.3 View FIGURE 9 ) matches well with that of Lagenipora cf. lepralioides View in CoL from the Alboran Sea, as figured by Ramalho et al. (2022, fig. 14A).