description. No clear consensus exists for the definition of this genus, and even the family assignment has been debated in the literature. Here we loosely follow the description given by Petrushevskaya (1986), which states that Botryopera species are small in size, with a sub-cylindrical, elongated skeletal shape, a thorax that is ~45–75 microns wide and never broader than 100 microns, and have arches connecting the thorax to the cephalis that reach ~1⁄3 of the way up the cephalic segment. Here we add that species in this genus often exhibit an axobate, which is a character common to the lophophaenid genera Ceratocyrtis andAntarctissa, but is otherwise not widely observed in this family. Botryopera species also tend to have a cephalis that is heavier and better developed than the thorax.

Remarks. Haeckel (1887) first described the genus Botryopera as one of two genera in the family Cannobotryida (Haeckel, 1881). He described Cannobotrys as the genus with porous tubes on the cephalis (a clear indication that these taxa should belong to the family Cannobotryidae), and Botryopera as the genus without these tubes. Two species previously described by Ehrenberg (1844), Lithobotrys triloba and Lithobotrys quadriloba, were placed into Haeckel’s new genus Botryopera. However, Ehrenberg’s first published illustrations of Lithobotrys triloba in 1854c (pl. 19, fig. 55; pl. 22, figs. 30A–B) suggests that it is a lophophaenid due to its cephalis shape, lack of lobes or tubes, and pore structure. Haeckel (1887) states that the cephalis is trilobate, but there appears to be some confusion, as it is the thorax, not the cephalis, that has three lobes in this species. Reexamination and photo documentation of Ehrenberg’s collections by Suzuki et al. 2009 clearly indicates that the species Lithobotrys triloba Ehrenberg, 1854c should belong to the family Lophophaenidae (Suzuki et al., 2009; pl. 20, figs. 3A–B, 9A–E). These photographs show that the overall shape, proportions, and internal skeletal structure are consistent with other lophophaenid taxa, and in particular there are common characteristics to the genus Trisulcus Popofsky, such as the three-lobed thorax and relatively small cephalis. Therefore, Ehrenberg’s species concept cannot be easily confused with a cannobotryid; Haeckel (1887) must have either have mislabeled the cephalis and thorax in his description, or perhaps he misidentified a specimen as Ehrenberg’s species. To our knowledge, Lithobotrys quadriloba Ehrenberg, 1844 was never illustrated, and is not often discussed in the literature. Accompanying his original genus description of Botryopera, Haeckel only illustrated two of the five species he placed in that genus: Botryopera cyrtoloba Haeckel, 1887 and Botryopera quinqueloba Haeckel, 1887. Botryopera quinqueloba is most likely a true cannobotryid, given its apparently tri-lobed cephalis. However, Botryopera cyrtoloba is depicted only in apical view, making it difficult to tell whether all three lobes actually belong to the cephalis (as Haeckel states), or if the species has a typical lophophaenid-type cephalis with a lobed or strongly-shouldered thorax (resembling a species like Trisulcus triacanthus or Botryopera triloba).

Popofsky (1913) synonymized Botryopera Haeckel under Botryopyle Haeckel, and placed it in the new family, Acrobotrusidae. However, he did not explain why all species in Botryopera should belong in Botryopyle, or the new family, Acrobotrusidae. While some Botryopera species described at the time could easily be considered cannobotryids, others, such as Botryopera triloba (Ehrenberg) Haeckel, 1887, could not. Subsequent authors did not follow Popofsky (1913)’s synonymy.

In 1954, Campbell listed Botryopera as a junior objective synonym of Lithobotrys, but did not provide any explanation for this. The type species of Lithobotrys was designated as Lithobotrys quadriloba Ehrenberg, 1844, which Haeckel (1887) had previously transferred to Botryopera, although neither author had illustrated it. Thus, the type species of the genus Lithobotrysis cryptic and may be either a cannobotryid or a lophophaenid. No type species of Botryopera was designated until Petrushevskaya’s (1975) emendation of Haeckel’s genus concept. She considered this genus to be in the family Lampromitridae Haeckel, along with Antarctissa and Ceratocyrtis, two genera now widely accepted to be lophophaenids. Petrushevskaya (1975) listed Botryopera cyrtoloba Haeckel, 1887 as the type species, and rejected Campbell (1954)’s synonymization with Lithobotrys. In addition, Petrushevskaya (1975) placed three species from Trisulcus into the revised concept of Botryopera. These species were discussed and illustrated in Petrushevskaya (1971) as Trisulcus borealis, Trisulcus braevispicula, and Trisulcus boldyrae. Petrushevskaya (1975) states that Botrypera triloba Ehrenberg is the most “typical” species group within this genus; therefore, it is unclear why she designated the poorly-illustrated Botryopera cyrtoloba Haeckel as the type species instead. Petrushevskaya (1981) considered Botryopera to be within Lithocampaninae, a new subfamily under Lampromitridae that also included the genus Trisulcus. Petrushevskaya (1986) showed that Botryopera is closely related to Antarctissa Petrushevskaya, 1967, but differs in having reduced skeletal dimensions, including a thorax never wider than 100 microns, which is often sub-cylindrical in shape. Sugiyama (1993) followed the genus concept established by Petrushevskaya (1975, 1981, 1986) but considered Botryopera to be in the family Lophophaenidae rather than Lampromitridae or the subfamily Lithocampaninae, which he determined to be junior synonyms of Lophophaenidae based on their internal skeletal structures. Sugiyama (1993) described several new species of Botryopera, all of which are well illustrated and in our opinion, clearly lophophaenids. However, each of these new species were given only a tentative generic assignment due to our poor understanding of the internal skeletal structure for all Botryopera species.

This genus is a problematic one and it is beyond the scope of this paper to resolve it. The majority of species in this genus are endemic to polar oceans, so it will require close examination of high latitude Botryopera species to gain a better understanding of the characteristics of this genus. However, several species observed during this study are tentatively assigned to the genus Botryopera due to their resemblance to species already placed in this genus. The modern concept of this genus is still very blurry, but most authors agree that it resembles the lophophaenid genera Trisulcus and Antarctissa, and should thus be considered a lophophaenid.

Here we observed the following species, which we provisionally consider to be Botryopera: Botryopera amabie n. sp., Botryopera babayagae n. sp., Botryopera bolotniki n. sp., Botryopera? daleki Renaudie and Lazarus, 2013a, and Botryopera setosa (Jorgensen, 1900) Kruglikova, 1989. We do not include Botryopera equiceps (Campbell and Clark, 1944) Petrushevskaya, 1986 as the original illustration by Campbell and Clark (1944) appears to indicate the apical spine passing through the center of the cephalis (likely placing this species in Lithomelissa). Campbell and Clark (1944) tentatively placed the species in Dictyocephalus. Petrushevskaya (1975) illustrated the species as Antarctissa equiceps (Campbell and Clark) group; these illustrations do not show the apical spine at all, so it does not seem to pass through the center of the cephalis. It is not clear to us whether these specimens are even conspecific. Because the original illustration would appear to fit Lithomelissa better than Botryopera or Antarctissa, we do not include it in our list of Botryopera species and hope that additional study can clarify this species concept in the future. Botryopera piperata Renaudie and Lazarus (2015) is tentatively transferred to Pelagomanes n. gen. later in this manuscript. Botryopera conica gladenkov and Devyatkin, 1992 appears to fit better in Antarctissa, and so is not included here. Botryopera deflandrei (Petrushevskaya, 1975) was transferred to Antarctissa by Lazarus (1990). Botryopera multiloba Haeckel, 1887 was never illustrated and to our knowledge has never been used or better documented in subsequent literature, so it is likely a nomen oblitum. Botryopera quinqueloba Haeckel, 1887 appears to be a cannobotryid rather than a lophophaenid, so we do not include it here. [Trubovitz et al. 2022]

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