Confettiella malaquiasi, Oskars, 2024

Oskars, Trond R., 2024, Release the confetti! A new genus and species of Indo-West Pacific bubble snails (Cephalaspidea: Haminoeidae), Journal of Natural History 58 (5 - 8), pp. 236-251 : 240-244

Confettiella malaquiasi sp. n.

( Figures 2A–F , 3A–F )

Haloa species – Poppe; Poppe (2023)

Type species

Confettiella malaquiasi sp. n.

Type locality

Inside lagoon near Doljo Pt., Panglao Is., the Philippines, coordinates: 9.585°N, 123.72669°E.

Zoobank: LSID: urn:lsid:zoobank.org:act:9B0BDC04-6622-47CE-B81C-C1CE2C17B8E6

Etymology

The genus name stems from the speckled pattern of multi-coloured dots covering the mantle and resembling the confetti, small candies, or paper strips thrown at festivals and celebrations. The suffix - ella (Latin) refers to a diminutive form, referencing the small size of the animal compared to other Haminoeidae . The species is named in honour of Manuel A.E. Malaquias, who is one of the foremost authorities on Cephalaspidea and was involved in the collection of these specimens.

Diagnosis

Animal background colour transparent grey, with brown blotches and white dots on cephalic shield and parapodial lobes; whitish mantle with scattered black, white, red, and orange dots. Cephalic shield rectangular, unlobed; eyes widely spaced; periocular area unpigmented. Hancock’s organ short, thick, ridge-like. Parapodial lobes short, barely folded up from foot. Squarish, short pallial lobe barely extends beyond apex. Shell round, bulbous, smooth, translucent; periostracum transparent; aperture wide tapering apically, columella narrow, separated from last whorl by furrow, forming a columellar lip. Buccal bulb oval, thick, muscular. Oesophagus long, widening to a small crop anterior of gizzard. Salivary glands long, nodular, proximally thin, widening to oval glands distally. Gizzard covered in thin tissue proximally, covered in thick muscle fibres distally. Jaws semi-circular, edges of rods rectangular in outline, rods with denticulate edges, 9–11 denticles, the denticles are longitudinally striate. Radula formula 18 × 4.1.1.1.1.4; rachidian with a single central cusp and coarse denticulation; lateral teeth hook shaped, smooth. Male reproductive system with bilobed prostate; distal lobe bulbous, smooth; proximal lobe oval, composed of clusters of pustules; short external seminal duct entering atrium laterally. Atrium elongated with thick muscular sheet, retractor muscles connect the atrium to the external seminal duct and prostate. Long, folded penial structure contained within atrium. Proximal part of penial structure connects laterally to the wall of the upper atrium, small warts exteriorly, distal part connects directly to internal seminal duct, internal seminal duct is connected to external seminal duct. Short retractor muscle connects internal seminal duct to penial structure. Female reproductive system with elongate vestibule; small blind sac protrudes form vestibule; small, globular, lamellate anterior mucus gland; duct emerging from anterior mucus gland splits to form median duct of posterior mucus gland and duct of albumen gland; posterior mucus gland elongated, tapering, distal end smooth, curved; three lobes separated by median duct; third lobe, short, nodular; albumen gland rounded, small glandular mass surrounding ampulla; gametolytic gland oval, small, connected to vestibule by long, slim gametolytic duct.

Material examined

Panglao 2004 station M9, coordinates: 9.585°N, 123.726669°E, field label M9 – OT870, mangrove, inside lagoon near Doljo Pt., Panglao Is., the Philippines. MNHN Paris MNHN-IM -2019-11,996, holotype here designated, H (shell height) = 1.5 mm, complete specimen ( Figure 2C ) . MNHN-IM-2019-11,997, paratype here designated, animal length = 3 mm, dissected and sequencing attempted . MNHN-IM-2019-11,998, paratype here designated, H = 2.5 mm, dissection and sequencing attempted ( Figure 2B ) . MNHN-IM-2019-11,999, paratype here designated, H = 1 mm, complete specimen.

External morphology. ( Figure 2A, F ). Animal background colour transparent grey, with brown blotches and white dots on cephalic shield and parapodial lobes; whitish mantle with scattered black, white, red and orange dots. Cephalic shield rectangular, unlobed; eyes widely spaced; periocular area unpigmented. Hancock’s organ short, thick, ridge-like. Parapodial lobes short, barely folded up from foot. Squarish, short pallial lobe barely extends beyond apex.

Shell. ( Figure 2B–C ). Shell round, bulbous, translucent, smooth, lacking spiral striae; periostracum transparent; aperture wide tapering apically, columella narrow, separated from last whorl by furrow, forming a columellar lip.

Male reproductive system. ( Figure 2D–E ). Reproductive system with bilobed prostate; distal lobe bulbous, smooth; proximal lobe oval, composed of clusters of pustules; short external seminal duct entering atrium laterally. Atrium elongated with thick muscular sheet, retractor muscles connect the atrium to the external seminal duct and prostate. Long, folded penial structure contained within atrium. Proximal part of penial structure connects laterally to the wall of the upper atrium, small warts exteriorly, distal part connects directly to internal seminal duct, internal seminal duct is connected to external seminal duct. Short retractor muscle connects internal seminal duct to penial structure.

Female reproductive system. ( Figure 2F ). Female reproductive system with elongate vestibule; small blind sac protrudes form vestibule; small, globular, lamellate anterior mucus gland; duct emerging from anterior mucus gland splits to form median duct of posterior mucus gland and duct of albumen gland; posterior mucus gland elongated, tapering, distal end smooth, curved; three lobes separated by median duct; third lobe short, nodular; albumen gland rounded, small glandular mass surrounding ampulla; gametolytic gland oval, small, connected to vestibule by long, slim gametolytic duct.

Anterior digestive system. ( Figure 3A ). Buccal bulb oval, thick, muscular. Oesophagus long, widening to a small crop anterior of gizzard. Salivary glands long, nodular, proximally thin, widening to oval glands distally. Gizzard covered in thin tissue proximally, covered in thick muscle fibres distally.

Gizzard plates. ( Figure 3B ). Gizzard plates with 20–22 fine transverse ridges; rachis present distally, absent proximally. No apparent rods on surface.

Radula. ( Figure 3C–D ). Radula formula 18 × 4.1.1.1.1.4; rachidian with a single central cusp and coarse denticulation; lateral teeth hook shaped, smooth.

Jaws. ( Figure 3E ). Jaws semi-circular, edges of rods rectangular in outline, rods with denticulate edges, 9 – 11 denticles, the denticles are longitudinally striate.

Distribution

Known only from the type locality.

Habitat

The field label states the specimens were collected in a mangrove.

Diet

A benthic diatom was found lodged in the gizzard plate ( Figure 2F ), possibly indicating that these are part of this species’ diet.

Remarks

During the work on the phylogeny and systematics of Haloa sensu lato ( Oskars and Malaquias, 2019), one whole specimen was photographed and DNA sequencing was attempted. The genetic markers from the two specimens on which sequencing was attempted were cytochrome oxidase 1(COI), 16S ribosomal ribonucleic acid(rRNA), 12S rRNA, 28S rRNA and Histone 3 (see Oskars and Malaquias 2020a). However, none of these genetic markers amplified successfully. The original vial held four specimens,the largest one lacking a shell and three smaller specimens that were deeply retracted within the shells. It was not possible to extract the shelled specimens without damaging the shell. These specimens were also distorted due to retraction and so small that it was not possible to dissect them in detail to observe the internal organs. For the specimen MNHN-IM-2019- 11,998 (H = 2.5), dissection was attempted, but with poor results as the shell broke upon extraction of the animal and the internal anatomy was too small to identify with certainty. Due to this,the whole specimen was extracted for DNA.However, as the gene amplifications all failed, the remaining specimens were set aside for more thorough anatomical study in the systematic revision of Lamprohaminoea ( Oskars and Malaquias, 2020a) , as it was assumed to be a juvenile Lamprohaminoea . The large shell-less specimen was dissected, but when it became apparent that it was likely a unique species within Haminoeidae , gene amplification and sequencing was attempted. Again, all failed; this could possibly be due to poor fixation, as sometimes even ethanol-fixated specimens do not yield sequences. Although the specimen information indicates that it was ethanol fixed, the specimens may have been initially fixated in buffered formalin, making DNA extraction and amplification difficult to impossible. The dissected animal was fully distended but lacked a shell. The shell could have been removed after sampling, but it could also be due to degradation from formalin fixation. Shell dissolution after formalin fixation and storage in ethanol sometimes occurs in thin-shelled cephalaspids, especially in smaller specimens (pers. obs). The cleaning process including Buffer ATL and proteinase K also did not work well, leaving the radula and gizzard plates covered in some tissue, and damaging the plates somewhat. This effect has previously been observed when attempting to dissolve tissue known to be formalin fixed (pers. obs). However, as only two retracted and tiny specimens remained, alternative methods to break down the tissue were not attempted to avoid damaging the remaining material. The holotype and paratype remain intact and it may be possible to study them by non-destructive methods in the future.

A similar but seemingly distinct species from Papua New Guinea has been photographed ( Haminoea sp. 7 : Gosliner et al. 2015, p. 31, 2018, p. 351), but otherwise there is no known species with similar external features. The species differs mainly in that ‘ Haminoea sp. 7 ’ has a mantle with yellow and bright orange dots but not many black and white blotches, a pallial lobe that is longer and narrower, and a broader cephalic shield with black markings and narrowly spaced eyes.

Figures

Figure 2. A, Live animals of Confettiella malaquiasi gen. n. et sp. n., the Philippines, Panglao (Courtesy of MNHN, Paris), presumably the larger, shell-less paratype (animal length 3 mm, MNHN-IM-2019- 11,997). B, Adapertural (left image) and apertural (right image) views of shell of wholly sequenced paratype (H = 2.5 mm, MNHN-IM-2019-11,998). C, Adapertural (left image) and apertural (right image) views of shell of holotype (H = 1.5 mm, MNHN Paris MNHN-IM-2019-11,996). D–F, Paratype, animal length 3 mm, MNHN-IM-2019-11,997. D, Complete male reproductive system. E, Detail of interior of dorsally opened atrium with extended penial structure (right image). F, Complete animal with shell and mantle removed, showing female reproductive system. Abbreviations: agl, albumen gland; am, ampulla; amg, anterior mucus gland; an, anus; at, atrium; dprl, distal prostate lobe; esd, external seminal duct; ga, genital aperture; gd, gametolytic duct; ggl, gametolytic gland; gz, gizzard; ho, Hancock’s organ; isd, internal seminal duct; la, labium; mc, mantle cavity; md, median duct; mrp, male reproductive system; ms, muscular sheath; par, parapodial lobe; pl, pallial lobe; pmgl1, posterior mucus gland lobe 1; pmgl2, posterior mucus gland lobe 2; pprl, proximal prostate lobe; ps, penial structure; rm, retractor muscle; smg, seminal groove; v, vestibule. Scale bars: D, E = 0.25 mm; F = 0.5 mm.

Figure 3. A, Anterior digestive system of Confettiella malaquiasi gen. n. et sp. n., the Philippines, Panglao (paratype, animal length = 3 mm, MNHN-IM-2019-11,997). B, Left lateral view of whole gizzard plate. C, Scanning electron microscopy (SEM) image of whole radula. D, SEM detail of radula with rachidian.E, SEM detail of jaw,showing rods with denticulation.F, SEM detail of diatom lodged in gizzard plate. Abbreviations: bb, buccal bulb; cr, crop; es, oesophagus; gz, gizzard; m, mouth; ms, muscular sheath; sl, salivary gland; st, soft tissue. Scale bars: A = 0.5 mm; B, C = 20 µm; D = 2 µm; E, F = 1 µm.