Parasmittina karlae Martha & Scholz, 2025, sp. nov.

Parasmittina karlae sp. nov. urn:lsid:zoobank.org:act: B9211284-693E-47C5-84D7-016F7EBD00D2 (Fig. 20.1–4) Material examined. Holotype: SMF 40790 (St. 283 KU; Fig. 20.1, 20.3–4). Paratype: SMF 10732 (St. 283 KU; Fig. 20.2). Additional material: SMF 40803 (St. 283 KU). Etymology. Named for the step-granddaughter of the second author, Karla Samadian (born 09 April 2017). Description. Colonies encrusting, multiserial, unilamellar (Fig. 20.1). Zooids arranged quincuncially, separated by distinct furrows. Septula inside vertical walls monoporous, elliptical. Ancestrula and early astogeny not observed. Autozooids subhexagonal to irregularly polygonal, 229–387 μm (ẋ = 315 ± 35 µm; CV = 11; N = 40 on 3 specimens) long by 191–312 μm (ẋ = 255 ± 32 µm; CV = 13; N = 40 on 3 specimens) wide (Fig. 20.2). Frontal shield flat, smooth or slightly pustulose. Areolar pores marginal, elliptical to slit-like. Primary orifice semielliptical, 61–92 μm (ẋ = 79 ± 6 µm; CV = 7; N = 40 on 3 specimens) long by 61–86 μm (ẋ = 71 ± 5 µm; CV = 7; N = 40 on 3 specimens) wide, proximally partially obscured by asymmetrical peristome, bearing a median lyrula proximally; pairwise, claw-like condyles at about one-third the orifice length, curved inwards towards the proximal margin of the peristome (Fig. 20.3). Peristome developed proximal to spine bases as prominent lateral lappets. Oral spine bases numbering seven in both ovicellate and non-ovicellate autozooids, distolateral and lateral to the orifice (Fig. 20.3). Ovicells hyperstomial, globular, formed by maternal zooid and distal zooid(s), 116–156 μm (ẋ = 139 ± 9 µm; CV = 6; N = 33 on 3 specimens) long by 140–189 μm (ẋ = 166 ± 13 µm; CV = 8; N = 33 on 3 specimens) wide; ectooecia partly covered by variably developed secondary calcification from distal zooid(s), pierced by 20–30 circular or teardrop-shaped pores, smooth and with occasional striae (Fig. 20.4). Avicularia and kenozooids not observed. Remarks. Parasmittina is among the most speciose cheilostome genera, with nearly 200 distinct species occurring circumglobally. However, the type material of its type species, Parasmittina Jeffreysi (Norman, 1876), originally reported from Baffin Bay west of Qeqertarsuaq, Greenland, has never been imaged. Powell (1968) and Winston & Hayward (2012) provided images of specimens they identified as Parasmittina Jeffreysi from the Bay of Fundy, and the coasts of New Hampshire and Maine, USA, respectively. From the Gulf of Aden, we describe Parasmittina karlae sp. nov., which is notable for two key characteristics: (1) the absence of adventitious avicularia and (2) the presence of seven oral spine bases (Fig. 20.3). The number of spine bases remains consistent across all autozooids; however, in fertile autozooids, the distalmost spine bases become covered by the proximal margin of the ovicell when the ectooecium remains intact (Fig. 20.4). The new species differs from other known species of Parasmittina in that it appears to lack adventitious (and/or vicarious) avicularia (see Table 10 in Farias et al. 2024 for a comprehensive key of diagnostic characters of most Parasmittina species). However, the possibility of adventitious avicularia in Parasmittina karlae sp. nov. cannot entirely be ruled out, as additional material from the Gulf of Aden may reveal their presence. Most Parasmittina species possess only one to four oral spine bases, with only a few species exhibiting a higher count. Among these, Parasmittina glabra Gordon & d’Hondt, 1997, from the northern Norfolk Ridge in the Pacific Ocean, has seven to eight oral spine bases. However, this species differs in having a peristome with a median sinus proximal to the lyrula and consistently occurring proximolateral avicularia. Ostrovsky et al. (2011) listed 15–16 Parasmittina species from the Red Sea based on previous literature, including several species in open nomenclature or yet to be formally described, while Scholz et al. (2001) listed four Parasmittina species from the Socotra Archipelago. Among the previously imaged Parasmittina species, only Parasmittina serrula Soule & Soule, 1973, has been reported with up to six oral spine bases. Originally described from the Hawaiian Islands, USA, and later recorded by Scholz (2000) from the Gulf of Aqaba, this species features small, circular areolar pores and paired lateral avicularia. Most other Parasmittina species from the Red Sea, including the widespread Parasmittina egyptiaca (Waters, 1909) (see Abdelsalam 2016), commonly exhibit frequent adventitious avicularia and no more than three oral spine bases.