Escharoides cavernicolus, Martino & Rosso & Taylor & Chiu & Fujita & Kitamura & Yasuhara, 2025
publication ID |
https://doi.org/10.26879/1433 |
publication LSID |
lsid:zoobank.org:pub:6E7554EF-C09B-4860-AC2A-FA1A6FD53B03 |
persistent identifier |
https://treatment.plazi.org/id/373A87F4-2D5C-D964-FCF4-F9ECDA70FCF7 |
treatment provided by |
Felipe |
scientific name |
Escharoides cavernicolus |
status |
sp. nov. |
Escharoides cavernicolus sp. nov. Di Martino, Rosso and Taylor
Figure 26 View FIGURE 26
zoobank.org/ F3A4DDF7-89DB-4A74-BA7A-939006E21AFE
Type material. Holotype PMC. B55. 29.7.2024 a, sample 19132 ( Figure 26A–D View FIGURE 26 ); paratype PMC. B55. 29.7.2024 b1, sample 19105 ( Figure 26E–F View FIGURE 26 ); paratype PMC. B55. 29.7.2024 b2, sample 19125 ( Figure 26G View FIGURE 26 ); paratype PMC. B55. 29.7.2024 b3, sample 19094 ( Figure 26H View FIGURE 26 ); Core 19, Daidokutsu cave, Okinawa, Japan, Holocene.
Etymology. Latin, meaning cave-dweller, referring to its commonness in the samples from Daidokutsu cave.
Diagnosis. Escharoides with 1–2 series of marginal areolar pores surrounding zooids avicularium cystids; 2–4 oral spines in autozooids, two if ovicellate; proximal peristome with extended median denticle; single or paired parallel-sided avicularia, with serrated rostrum, of variable size and position, either placed laterally to orifice juxtaposed with its margin and distally directed, or placed below orifice on the side of zooids, directed proximolaterally; ovicell globular with marginal pores and central umbo; dorsal side with conical pillars; ancestrula tatiform.
Description. Colony encrusting, multiserial, unilaminar, with dorsal side featuring pillars developing medially in correspondence with most zooids. Autozooids distinct, separated by thin furrows, oval to rounded hexagonal, longer than wide (mean ZL/ ZW 1.42). Frontal shield smooth, slightly nodular, imperforate except for one or two rows of marginal pores, circular, elliptical or drop-shaped margins, consistently and orderly arranged between ridges along zooidal margins (35–85 µm in maximum diameter), and around avicularian cystids (15–35 µm in maximum diameter). Primary orifice situated deep inside the peristome, rounded quadrangular, approximately as long as wide (158 µm in the single zooid measured); peristome well-developed proximally and laterally, bearing a rectangular median denticle measuring 30–40 µm in length by 30–60 µm in width at the base, extending approximately 120 µm inside the peristome; 2–4 oral spine bases, 35–50 µm in diameter, two visible in ovicellate zooids. Avicularia adventitious, present in two sizes and positions, either small and placed laterally to orifice, juxtaposed with its lateral margin, directed distally, or large and placed on zooidal lateral sides, directed proximolaterally. Four avicularian configurations observed: i) single small avicularium on one side of zooid; ii) a small avicularium juxtaposed with lateral margin of orifice and a large one on the zooidal side; iii) two small avicularia each juxtaposed with orifice side; iv) two large avicularia on each zooidal side. Rostrum raised, serrated, parallel-sided or slightly spatulate; opesia rounded triangular; crossbar complete. Ovicell hyperstomial, globular; ooecium smooth, nodular, with peripheral pores, 50–92 µm in diameter, small umbo centrally, and proximal margin raised and bent. Ancestrula tatiform, elliptical, 300 µm long by 270 µm wide (excluding gymnocyst), with extensive, wrinkled gymnocyst (c. 180 µm long) proximally, and narrow, smooth cryptocyst steeply sloping into the circular opesia, about 200 µm in diameter; 11 spines on the gymnocyst, indenting the cryptocyst, with circular or elliptical bases, 30– 60 µm in maximum diameter. Three zooids budded directly from the ancestrula, one distally and two distolaterally, slightly smaller than later autozooids (610–720 µm long by 330–420 µm wide), with a single avicularium, slightly smaller than those found on later autozooids, placed laterally.
Measurements (µm). ZL 968±64, 873–1056 (1, 6); ZW 681±67, 591–743 (1, 6); AvL (small type) 230±34, 159–278 (2, 13); AvW (small type) 86±11, 65–98 (2, 13); AvL (large type) 430±75, 296–544 (2, 11); AvW (large type) 136±21, 91–167 (2, 11); OvL 360±30, 317–385 (1, 4); OvW 454±47, 385– 494 (1, 4).
Remarks. Escharoides cavernicolus sp. nov. is one of the most common and abundant species found in the Daidokutsu cave samples. The configuration of its avicularia is highly distinctive. Other Recent and fossil Escharoides species described from Japan include: the Pleistocene to Recent E. adeonelloides (Ortmann, 1890) , which exhibits erect bilaminar colonies with oral spines present only in early ontogeny (Mawatari and Kii, 1952; Hirose, 2010); E. hataii Hayami, 1975 , a Pleistocene species with or without a single avicularium and 1–3 spines, lacking a peristomial denticle (Hayami, 1975); E. ramulosum Okada and Mawatari, 1937 , characterized by erect colonies with cylindrical branches; and E. sauroglossa Levinsen, 1909 , which has paired avicularia, with one typically being very spatulate, consistently placed laterally to the orifice, directed distolaterally (Mawatari and Kii, 1952; Hirose, 2010).
We have used the masculine ending “-us” in naming our new species, in accordance with Article 30 of the International Code of Zoological Nomenclature (ICZN, 1999), which states that genera ending with the suffix “-oides” are always masculine unless otherwise specified by the author. In Milne-Edwards (1836), there is no clear definition of the genus or its gender, therefore the ICZN should be followed. Currently, in Escharoides , there are various combinations, indicating that different authors have treated this genus as masculine, feminine (likely due to its inferred derivation from Eschara , which contains the majority of species), or neuter. This situation should be revised according to the code, which clearly states how the gender of genus-group names should be determined. The same issue likely affects many other bryozoan genera.
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