Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Echinoderes goku Rucci & Neuhaus & Bulnes 2022, sp. nov.

Echinoderes goku sp. nov. http://zoobank.org/ urn:lsid:zoobank.org:pub: 93EF677E-1755-41C7-8906-952614E71018 Diagnosis. Echinoderes with middorsal spine on segments 4, 6, and 8, and spine in lateroventral positions on segments 6–9 and 11 (lateral terminal spines). Tube present in subdorsal position on segment 2, sublateral to midlateral position on segments 7 and 9, lateral accessory position on segment 8, lateroventral position on segment 5 and ventrolateral position on segment 2. Type-2 gland cell outlets, female-specific papillae or subcuticular funnel-like structures not present. Male with a sublateral tube on segment 10 with a basal cylindrical reinforcement structure and three pairs of penile spines on segment 11. Female with sublateral fringe on surface connected with a subcuticular conical structure surrounded basally by a cylindrical reinforcement structure in segment 10 and with a lateral terminal accessory spine on segment 11. Etymology. The specific epithet is a noun in apposition and alludes to the adoptive name of the Saiyan Son Gok&umacr;, the major character from the Dragon Ball manga, authored by Akira Toriyama. Material examined. Holotype: Male (MACN-In 43755), collected on March 31, 2019 by Agustín G. Menechella (IADO, CONICET, Argentina), at station E29 during the campaign aboard the Motorsailer “Bernardo Houssay” through the Argentinean continental shelf (Fig. 1), at 40 m depth using a dredge; mounted as glycerol-paraffin slide on Cobb aluminum frame. Paratypes mounted as glycerol-paraffin slides on Cobb aluminum frames: 1) material deposited at the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Buenos Aires, Argentina: one male and two females (catalogue numbers MACN-In 43756a –43756c); 2) material deposited at the Museum für Naturkunde Berlin, Germany, collection “Vermes”, “Generalkatalog freilebende Würmer”: 12 females and 19 males (catalogue numbers ZMB 12262, 12264, 12265, 12314–12331, 12334–12344). Non-types, deposited at Museum für Naturkunde Berlin: four males (ZMB 12263, 12266, 12332, 12333) and five juveniles (ZMB 12267–12269, 12345– 12347) mounted as glycerol-paraffin slides on Cobb aluminum frames and two adults of undetermined sex (ZMB 12270, 12351), one male (ZMB 12350), and four females (ZMB 12271, 12272, 12348, 12349) mounted for SEM on two stubs. All paratypes and non-types collected at same locality and date by same person as the holotype. Type locality. South West Atlantic Ocean, Argentinian continental shelf, off Pehuen-Có and Monte Hermoso, 39°06.7’S, 061°26.5’W, 40 m depth. Description. Adults with head, neck, and 11 trunk segments (Figs 2A,B, 3A,C, 6A). For a complete overview of measures and dimensions see Table 2. Distribution of cuticular structures, i.e., sensory spots, gland cells, conical structures, spines and tubes, is summarised in Table 3. Head. Head consisting of a retractable mouth cone and an introvert (Figs 3A,C, 6A–C). Mouth cone equipped with 9 outer oral styles, each with two articulating elements and neighbouring styles slightly alternating in length (Figs 4K, 6B). Each outer oral style possessing at its base a posterior central fringe of spinose processes and one anterior lateral spinose process on each side (Fig. 6B). Posterior spinose processes may be split apically into two processes (Fig. 6B). Although two out of three specimens mounted for SEM appeared with the introvert extended, the information on scalid numbers and arrangement is scarce because of particles partially masking characters. Both odd and even-numbered sectors showing seemingly 6 spinoscalid rings (Fig. 6C). All spinoscalids composed of a broader sheath-like base with a terminal fringe of spinose processes and an articulating terminal element ending bluntly in the primary spinoscalids and spinose in rings 02–06 (Fig. 6C). Terminal element covered with short cuticular hairs. Each primary spinoscalid revealing apically on its base two prominent fringes of spinose processes (Fig. 6C). One prominent apical process also found on the basis of ring 03 spinoscalids but not on those of the following rings. Spinoscalid of ring 06 of each second sector appearing to be much smaller than that of its neighbouring sector. Six short and hairy trichoscalids with trichoscalid plates being present, opposite to the neck placids 2, 6, 8, 10, 12 and 16. Neck. Neck equipped with 16 trapezoidal placids (Figs 2A,B, 3E, 4D), wider posteriorly and with rounded edges anteriorly in SEM of at least one specimen revealing placids at full length (ZMB 12270; not shown here). In light microscopy, anterior end of each placid of almost all specimens looking as if bent partly backwards (Figs 2A,B, 3E, 4D, 5A), possibly because of the thin cuticle revealed by most specimens (see below). Midventral placid wider than the remaining ones. All placids articulating with the first trunk segment. Trichoscalid plates present on paradorsal (8 and 10), laterodorsal (6 and 12) and ventromedial (2 and 16) placids. Trunk. Segments 1 and 2 formed by a closed cuticular ring (Figs 2A,B, 4A,D, 8C) and the remaining ones by one tergal and two sternal plates (Figs 2A,B, 3E,F,J, 4A–E,I, 5A–C, 6A, 7, 8B,D–F). Midsternal and tergosternal junctions well-developed, however, the latter being less conspicuous and sometime hard to see under the light microscope. Pachycycli present anteriorly on segments 1–11 (Figs 3E,F,J, 4A–E,I,J, 5A–C). Cuticular hairs not abundant and filiform (Figs 3E,F,J, 5A–C, 6A, 7A–E, 8B–F). The bracteate hairs on segments 2–10 arranged in one or two irregular wavy rows (Figs 6A, 7A–E, 8C–F). Hairs of anterior row shorter than those of the posterior one (Figs 6A, 7A–E, 8C–F). Well-developed patch of short, stronger cuticular hairs in three rows present paraventrally and centrally on segments 3–6 (Figs 4D, 8C–E) and, less developed, also on segment 7 (Fig. 8E). Segments 4– 10 with a ventrolateral to paraventral patch of thin cuticular hairs organised in a single or sometimes in two or three rows (Fig. 8D–F). Most adult specimens having moulted recently recognizable by differing extent of fusion of button-like structures in cuticular flap at posterior end of each segment (comp. Figs 4D,F–I, 5A, 9B,D,F–H). Primary pectinate fringe well-developed in segments 2–11 and formed by teeth usually of even length and width within a segment (Figs 3E,F,J, 4I, 5B,C, 7, 8B–F). Fringe appearing shorter on anterior three segments than in remaining segments and almost lacking dorsally on segment 10 (Fig. 7D,E), narrower ventrally on segment 10 than on remaining segments (Fig. 8F). Secondary pectinate fringe present as a single row of very short cuticular processes dorsally and ventromedially (Figs 7C, 8F). Type-1 sensory spots (Figs 2, 3E–J, 4A–D,F–I, 5A–C, 7A–E, 8C–F) and type-1 gland cell outlets (Figs 2, 3E,G,H,J, 4A,B,D–G,I, 5A,B) present. Type-2 gland cell outlets and female-specific papillae or funnel-like or pear-shaped subcuticular structures absent on any segment. Segment 1 (Figs 2A,B, 3E, 4A,D, 5A, 6A, 7A, 8C; Table 3) lacking spines and tubes. Sensory spot usually with 2 but sometimes with up to 5 pores present centrally in subdorsal, midlateral and ventromedial position, flanked by long cuticular hairs. Type-1 gland cell outlet occurring centrally in middorsal and anteriorly in lateroventral position. Other hairs than those associated with sensory spots not existing on this segment. Primary pectinate fringe as row of very short teeth with a blunt tip, broader than teeth of remaining segments. Segment 2 (Figs 2A,B, 3E, 4A,D, 5A,C, 6A, 7A, 8C; Tables 2, 3) with subdorsal and ventrolateral tube. Sensory spot present posteriorly in middorsal and midlateral position and centrally to posteriorly in ventromedial position. Type-1 gland cell outlet occurring anteriorly in middorsal and ventromedial position. Cuticular hairs scarce on this segment, but more evident if associated with the sensory spots. A few additional hairs emerging from cuticular perforation sites. Segment 3 (Figs 2A,B, 3E, 4A,D, 5A,C, 6A, 7A, 8C; Table 3) without spines and tubes. Sensory spot present posteriorly in subdorsal and sublateral position. Type-1 gland cell outlet occurring anteriorly in middorsal and centrally in ventromedial position. Cuticular hairs more abundant than on the previous segment and organised similarly on the remaining segments. Segment 4 (Figs 2A,B, 3E, 4A,D, 5A,C, 6A, 7B, 8D; Tables 2, 3) with a middorsal acicular spine. Sensory spots lacking on this segment. Type-1 gland cell outlet occurring anteriorly in paradorsal and centrally in paraventral to almost ventromedial position. Segment 5 (Figs 2A,B, 3E, 4A, 5A,C, 6A, 7B, 8D; Tables 2, 3) with lateroventral tube. Sensory spot present posteriorly in subdorsal, sublateral to midlateral position and almost centrally in ventromedial position. Sublateral to midlateral spot of segments 5 and 6 slightly more dorsally than spot of segment 3. Type-1 gland cell outlets occurring anteriorly in middorsal and centrally in paraventral to almost ventromedial position. Segment 6 (Figs 2A,B, 3F,J, 4B, 5B,C, 6A, 7B, 8D; Tables 2, 3) with middorsal and lateroventral acicular spine. Sensory spot present posteriorly in paradorsal and sublateral to midlateral position and almost centrally in ventromedial position. Type-1 gland cell outlet occurring anteriorly in paradorsal and centrally in paraventral to almost ventromedial position. Segment 7 (Figs 2A,B, 3F,J, 4B, 5B,C, 6A, 7C, 8D; Tables 2, 3) with sublateral to midlateral tube and lateroventral acicular spine. Sensory spot present posteriorly in subdorsal position and almost centrally in ventromedial position. Type-1 gland cell outlet occurring anteriorly in middorsal and paraventral to almost ventromedial position. Segment 8 (Figs 2A,B, 3F,J, 4B,I,J, 5B, 6A, 7C, 8D,E; Tables 2, 3) with a middorsal acicular spine, lateral accessory tube and lateroventral acicular spine. Middorsal spine of female much longer (92–98 µm) than that of male (54–79 µm) (Table 2). Sensory spot present posteriorly in paradorsal position. Type-1 gland cell outlet occurring anteriorly in paradorsal and paraventral to almost ventromedial position. Segment 9 (Figs 2, 3F,G,J, 4B,C,I,J, 5B,F,G, 6A, 7D, 8E,F; Tables 2, 3) with sublateral to midlateral tube and lateroventral acicular spine. Sensory spot present posteriorly in paradorsal and centrally in laterodorsal and ventrolateral position. Type-1 gland cell outlet occurring anteriorly in paradorsal and centrally in paraventral position. Segment 10 (Figs 2, 3G,H,J, 4B,C,E–J, 5B,D,E, 6A, 7D–F, 8B,F; Tables 2, 3) without spines but with sublateral to midlateral straight short tube with basal cuticular cylindrical reinforcement structure below trunk cuticle in male (Fig. 4F,H). Female without tube but with sublateral to midlateral subcuticular, conical structure (Figs 5D,E, 10C) ending in short apical cuticular duct through trunk cuticle, with basal cuticular cylindrical reinforcement structure below trunk cuticle (Fig. 5D,E), opening to outside via fringed pore (Fig. 7E,F). Sensory spot present posteriorly in subdorsal and ventrolateral position. Type-1 gland cell outlet occurring anteriorly in middorsal and centrally in middorsal and paraventral position. Posterior margin of each sternal plate progressing more posteriorly midventrally than lateroventrally. Segment 11 (Figs 2, 3H,I, 4F–J, 5D,E, 6A, 7D,E, 8A,B,F; Tables 2, 3) with lateral terminal spine, varying considerably in length (146–208 µm) in both females and males (Table 2). Straight lateral terminal accessory spine present in females (Figs 2C,D, 4I,J, 5D, 6A, 7D,E, 8F; Tables 2, 3) and three penile spines appearing in males, one bent, tubular, longer, in lateral accessory position, one shorter, broader, almost triangular, slightly more dorsally, and one bent, tubular, longer sublaterally (Figs 2A,B, 4F,G, 8A; Tables 2, 3). Sensory spot present posteriorly in subdorsal position. Males often with two ventrolateral pores, unclear if belonging to a sensory spot. Two type-1 gland cell outlets occurring anteriorly and centrally behind each other in middorsal position. Tergal extensions triangular-shaped. Among the 39 specimens studied by LM and three specimens investigatable with SEM no variation of characters was found except that the position of sensory spots on segment 5 and 6 and of tubes on segments 7 and 9 varied slightly from more sublaterally to more midlaterally. Probably, one specimen (ZMB 12323) possessed a lateroventral spine only on the right side of segment 7. Juvenile stages. Five specimens could be identified as juvenile stages based on their thin trunk cuticle, the postmarginal spicula, a gap in the arrangement of cuticular hairs and postmarginal spicula about ventromedially to paraventrally where the dorsoventral muscles attach (Fig. 9B,C,E), papillate sensory spots (Fig. 10A) if present at all, the lack of recognisable gland cells, an acicular spine middorsally on segment 9 (Fig. 10A) and lateral accessorily on segment 10 (Fig. 10C), and a well developed lateral terminal accessory spine (Fig. 9A,E,F). It was not possible to identify different life history stages with certainty, because the specimens came out crumpled, twisted, and folded during mounting due to their thin cuticle. In all specimens, 11 trunk segments delimited by postmarginal spicula could be recognised, whereas sensory spots were difficult to trace. Four specimens seemed to represent late juvenile stages if not the last stage, and the fifth was moulting to a female, and this is subsequently described in more detail and documented. ......continued on the next page TABLE 2. (Continued) Last juvenile stage moulting. One specimen was fixed while moulting from the last juvenile stage to the adult stage (ZMB 12267, Fig.9A). Each of the 11 trunk segments of the juvenile specimen was covered by numerous short cuticular hairs in its central part and showed a row of postmarginal spicula posteriorly on each segment (Figs 9B–H, 10A,B). An acicular spine occurred middorsally on segments 4, 6, 8 and 9 (Figs 9H, 10A), in lateral accessory position on segments 10 (Fig. 10C) and 11 (= lateral terminal accessory spine), and lateroventrally on segments 6–9 and 11 (= lateral terminal spine) (Figs 9, 10A). A straight tube was found sublaterally on segments 7, 9 and 10 (Fig. 10B), lateral accessorily on segment 8, lateroventrally on segment 5, and ventrolaterally on segment 2. A papillate sensory spot appeared at least paradorsally on segments 6, 8 and 9 (Fig. 10A), subdorsally on segments 10 and 11 and possibly on segment 5, ventrolaterally on segments 9–11, and ventromedially on segments 1 and 5–7. The moulting adult possessed in the free flap of segments 1–10 the button-like structures, which are typical of recently moulted adults (Fig. 9B,D,G,H). The adult lacked the middorsal spine on segment 9 and the lateral accessory spine on segment 10 as well as the sublateral tube on segment 10. In the latter position, it revealed a subcuticular conical structure with a basal cuticular reinforcement structure (Fig. 10C). Additional material. A reinvestigation of sublateral to midlateral subcuticular characters in segment 10 of 14 species of Echinoderidae revealed the following results: (1) Female and male Echinoderes unispinosus unveiled a subcuticular conical structure (Fig. 5J). (2) Female and male E. meteorensis had a subcuticular very small conical structure plus a cylindrical reinforcement structure at the base of the laterodorsal tube (Fig. 5H,I). (3) Female and male E. apex possessed a subcuticular spherical structure at the base of the laterodorsal tube (Fig. 5K,L). (4) Female and male E. capitatus and E. ferrugineus expressed a subcuticular cylindrical reinforcement structure at the base of the laterodorsal tube (E. capitatus, Fig. 5F,G) or a tube was missing (E. ferrugineus, Fig. 5M). (5) Female and male E. pilosus exhibited a subcuticular reinforcement structure at the base of the laterodorsal tube plus an external cylindrical cuticular sheath surrounding the basal part of the tube (Fig. 5N). (6) Female Cephalorhyncha asiatica, Echinoderes applicitus, E. bathyalis, E. multiporus, E. pterus, Fissuroderes higgins, F. thermoi, and Polacanthoderes martinezi did not show any subcuticular structures, males were not studied.Published as part of Rucci, Kevin A., Neuhaus, Birger & Bulnes, Verónica N., 2022, A new species of Echinoderes (Kinorhyncha: Cyclorhagida: Echinoderidae) from the Argentinean continental shelf with notes on its postembryonic development and on subcuticular morphological characters unreported for Kinorhyncha, pp. 65-90 in Zootaxa 5099 (1) on pages 68-82, DOI: 10.11646/zootaxa.5099.1.3, http://zenodo.org/record/603690

A new species of Echinoderes (Kinorhyncha: Cyclorhagida: Echinoderidae) from the Argentinean continental shelf with notes on its postembryonic development and on subcuticular morphological characters unreported for Kinorhyncha

Rucci, Kevin A., Neuhaus, Birger, Bulnes, Verónica N. (2022): A new species of Echinoderes (Kinorhyncha: Cyclorhagida: Echinoderidae) from the Argentinean continental shelf with notes on its postembryonic development and on subcuticular morphological characters unreported for Kinorhyncha. Zootaxa 5099 (1): 65-90, DOI: https://doi.org/10.11646/zootaxa.5099.1.

Thysanozoon mirtae Bulnes, Albano, Obenat & Cazzaniga, 2011, sp. nov.

Thysanozoon mirtae sp. nov. Figures 7–9 Diagnosis. Pseudocerotidae with papillated surface, ground colour greenish yellow covered with rounded black spots, more densely distributed on a mid dorsal band. The papillae are elongated, reddish brown; with a marginal band and cerebral area free of papillae. Conspicuous marginal, colourless tentacles. Two cerebral eye clusters present. The tentacular eyes extend from the fore margin, where they are arranged in a single marginal band, backwards up to the base of the tentacles where they are scattered. Male copulatory apparatus double with conspicuous spermiducal vesicles, a single true seminal vesicle, free prostatic vesicle and a slightly asymmetric stylet. The ejaculatory duct joins the prostatic duct proximally at the base of the penis stylet. Male atrium short, narrow and ciliated. Vagina ciliated, without a cement pouch. Female atrium small and ciliated. Separated gonopores. Ventral sucker in the fore body half. Type material. Holotype: 9.0 μm sagittally sectioned specimen, mounted on 180 slides. Collected by M.J. Albano, 21 February 2009 from the Club Náutico de Mar del Plata. On a mussel and ascidians community, 1–2 m depth. MACN-In 38207. Etymology. The specific name is dedicated to the memory of Mariano Albano´s mother, Mrs. Mirta R. Elías. Description. Large, elongated, 36.5 mm long by 20 mm wide alive, 35 mm by 18.4 mm preserved. Marginal tentacles formed by foldings of the fore margin. Dorsal surface covered with elongated reddish brown papillae which are longer and more thickly placed in the centre, declining in length and number to the margins, leaving a marginal band free of papillae. Ground colour is greenish yellow covered with rounded black spots, more densely distributed on a mid dorsal band. With an interrupted reddish brown marginal band. Marginal tentacles without pigmentation, extending between the tentacle bases and reaching the brain dorsally (figures 7 A– 7 B). The dorsal tentacular eye spots are numerous, distributed dorsally in a single row and ventrally scattered. The cerebral eyespots form two separated triangular clusters joining anteriorly. Frontal eyes scattered (figure 7 D). Pharynx ruffled, 5.5 mm long (figure 7 C). The mouth opens at 14 mm from fore margin, behind the pharynx cavity. The main gut opens in the middle of the pharynx cavity roof and runs distally up to short behind the female system. The intestinal ramifications give out extensions into the dorsal papillae (figure 9 C). Dorsal body wall 103 µm high. The ciliated cellular epidermis bears rhabdites and granular pigmentation. The elongated rhabdites are densely packed on the epidermis of the papillae and are readily seen as small red small rods even in living specimens. The granular pigmentation is distributed mostly in the epidermis free of papillae. Beneath the epidermis a layer of circular muscle fibres is present, followed by a longitudinal muscle layer. Ventral body wall 110 µm high, without rhabdites but with granular pigmentation. Beneath the basement membrane, there are a layer of circular muscle fibres and an innermost layer of longitudinal muscle fibres. The ventral epidermis is higher than the ventral one, the ventral circular layer is thinner than the dorsal one, and the ventral longitudinal layer is much higher and dense than the dorsal one. Body parenchyma immersed in a dense net of parenchymatic muscle fibres, giving the body a strong appearance (figure 9 D). The testes are small, widely spaced and ventrally arranged beyond the uteri. The uteri are dorsal to the testes, but ventral to the gut. They are well developed, filled with numerous eggs and located behind the spermiducal vesicles. The male copulatory system is double. Each copulatory organ consists of a true seminal vesicle, free prostatic vesicle and penis papillae armed with a stylet (figure 8). The vas deferens runs ventrally from the rear. After it passes the ventral sucker, the vas deferens distends to form a few voluminous spermiducal vesicles (figure 9 E) before entering the elongated seminal vesicle. The seminal vesicle has a well developed muscular wall and is arranged dorsally to the male prostatic vesicle and stylet. The rounded prostatic vesicle shows a muscular wall and a very high, smooth glandular inner lining. The ciliated ejaculatory duct follows a short trajectory until reaching the penis papillae, its muscular wall being well developed. The prostatic duct is short and straight, joining the ejaculatory duct at the basis of the penis papilla. The stylet is conical and elongated, 760 µm long, slightly asymmetric and sharp. The male atrium is short and narrow, ciliated and directed backwards, opening to a male gonopore located 12 mm from the fore margin (figure 9 B). The second male copulatory organ is similar to the one already described. Both male copulatory organs are symmetrically arranged left and right of the longitudinal body axis. The female reproductive system is single (figure 8). The oviducts enter separately the vagina from the rear, turning ventrally to open distally into a small female atrium and a median gonopore. The canal is about the same diameter along the whole trajectory. The vagina is surrounded by scarce cement glands. There is no cement pouch. The vagina and atrium are completely ciliated. Taxonomical discussion. Thysanozoon mirtae sp. nov. is the only known species having slender, elongated dorsal papillae of reddish brown colour on a greenish yellow body covered with rounded black spots with a reddish brown marginal band; the marginal tentacles and cerebral area devoid of pigment complete an exclusive colour pattern. The presence of slender papillae was described for Thysanozoon skottsbergi Bock, 1913 and T. distinctum Stummer-Traunfels, 1895, while T. minutum Stummer-Traunfels, 1895 has a similar ground body colour. However, the dorsal papillae of T. mirtae sp. nov. differ from the papillae of T. skottsbergi because of the absence of darker pigmentation. The margin of T. distincutum is golden yellow and that of T. minutum is white, sharply different from the reddish brown marginal band of T. mirtae sp. nov. The spermiducal vesicles are thin-walled expansions of the vas deferens serving as storage of sperm (Faubel 1983, p. 21) different from the spermiducal bulbs, which are more muscularized structures, presumably assisting the propulsion of sperm. The apparent spermiducal vesicles and the strongly developed parenchymatic musculature are two main features characterizing the new species T. mirtae. It differs readily from the only species of Thyzanozoon with which it was recorded in sympatry, T. brocchii (Risso 1818), both in colour and anatomy. While T. mirtae is dorsally greenish yellow, covered with translucent, slender reddish brown papillae, with spermiducal vesicles and a well developed mesenchymatic musculature; T. brocchii is dorsally light-brown, covered with, solid, blunt dark brown papillae, without spemiducal vesicles and few mesenchymatic muscle fibres.Published as part of Bulnes, Verónica N., Albano, Mariano J., Obenat, Sandra M. & Cazzaniga, Néstor J., 2011, Three Pseudocerotidae species (Platyhelminthes, Polycladida, Cotylea) from the Argentinean coast, pp. 30-44 in Zootaxa 2990 on pages 39-41, DOI: 10.5281/zenodo.20231

Thysanozoon brocchii Risso 1818

Thysanozoon brocchii (Risso 1818) (Figures 4–6) Examined material. Voucher: 8.0 μm sagittally sectioned specimen, mounted on 81 slides. Collected by M.J. Albano, 9 May 2008, North Breakwater of the Mar del Plata harbour. On a mussel and ascidians community, 1–2 m depth. MACN-In 38206. Morphology. Large, oval, 26 mm long by 15 mm wide alive, 23 mm by 14 mm preserved. Marginal tentacles formed by foldings of the fore margin, conspicuous, oriented dorsally and directed backwards, distally enlarged, with no pigmentation. Ground colour is light brown, delicately translucent in the margins, centrally yellowish brown. Round black spots cover the dorsal surface, especially in a wide marginal area. Dorsal surface covered with big bulky conical dark brown papillae, which are longer and more densely distributed to the sides of the dorsal bulge, but scattered on the bulge itself, and declining in length and number to the margins, leaving the margin free of papillae. A second area free of papillae extends from the cerebral eyes up to between the tentacle bases (figures 4 A– 4 B). Though the presence of blunt dorsal papillae gives the animal a solid appearance, the body itself is very delicate and frail. The dorsal tentacular eyespots are numerous on the dorsal surface, distributed in a single row; they are scattered ventrally. The cerebral eyespots form two separated triangular clusters. Pharynx ruffled, 320 µm long. The mouth opens at 7.2 mm from anterior margin, in the middle of the pharynx cavity. The main gut opens in the middle of the pharynx cavity roof and runs distally up to short behind the female system. Intestinal ramifications are conspicuous and numerous, running parallel to the body surface and giving out extensions into every dorsal papilla (figure 6 D). Ventral sucker at 13 mm from the fore margin of the body (figure 4 C). Dorsal body wall 50 µm high. The ciliated cellular epidermis has rhabdites and granular pigmentation. The cilia are very short, and the rhabdites and pigmentation are abundant and more densely packed on the papillae, but they are scattered on the dorsal epidermis. Beneath the epidermis a frail layer of circular muscle fibres is present, followed by a longitudinal muscle layer. The granular pigmentation is present in the epidermis and the circular muscle layer. Ventral body wall 70 µm high. The cilia are numerous and longer than those on the dorsal epidermis. Ventral surface with scarce rhabdites and no granular pigmentation. Beneath a well defined basement membrane, a thin layer of circular muscle fibres is underlain by a layer of loose longitudinal muscle fibres. The testes are latero-ventrally distributed but especially greatly accumulated in the rear part of the body (figure 4 C, 6 C), beyond the uteri. The ovaries are dorsal; the uteri are short, filled with small and few mature cells. The male reproductive system is double. Each male copulatory organ consists of a true seminal vesicle, free prostatic vesicle and penis papilla armed with a stylet (figure 5). The swollen vas deferens runs ventrally before entering the elongated seminal vesicle. The seminal vesicle is curved and dorsal to the male prostatic vesicle and stylet; it has a well-developed muscular wall and its lumen is narrow. The rounded prostatic vesicle has a muscular wall and a very high, smooth glandular inner lining. The ciliated ejaculatory duct describes a tortuous trajectory up to reach the penis papilla, having a well-developed muscular layer. The prostatic duct is short and straight, joining the ejaculatory duct beyond the point where the stylet is attached. The stylet is conical and elongated, 330 µm long and slightly curved. The penis sheath is ciliated, short and narrow (figure 6 A). The spacious male atrium is ciliated and directed forwards, opening to a male gonopore located 7.6 mm from the fore end. The second male copulatory organ is similar to the one already described. The female reproductive system is single (figure 5). The oviducts enter the vagina separately from the rear end. The canal is proximally swollen, later narrowing and turning ventrally, to finally enlarge distally. The fore and middle tract of the vagina is immersed in an eosinophilic glandular mass (figure 6 B). There are no cement glands either distally to the vagina or surrounding the elongated female atrium. Without an apparent cement pouch, the vagina and atrium are completely ciliated, underlain by a frail layer of circular muscle fibres. The female atrium opens to a female gonopore ventrally in the midline of body. Taxonomical discussion. Species in genus Thysanozoon are identifiable by their papillated dorsal epidermis, each species showing a definite body shape, a particular distribution of the papillae and a specific colour pattern. The studied specimen of T. brocchii from Mar del Plata matched the detailed descriptions of this species made by Lang (1884) and Stummer-Traunfels (1895). Under the current frame of morphological identification, the crucial characters that discriminate T. brocchii from its relatives are the dorsal surface covered with large bulky conical dark brown papillae, with the margin and cerebral areas free of papillae; its ground colour light brown, delicate translucent in the margins, and the internal anatomy being consistent with the descriptions of the T. brocchii specimens described for Brazil, Curaçao and Patagonia (Marcus 1949, 1952; Marcus & Marcus 1968; Brusa et al. 2009). Marcus (1949) described T. lagidium from the coast of Brazil; later on, after comparing the anatomy with the specimen from Curaçao and Europe, he synonymised T. lagidium with T. brocchii (Marcus & Marcus 1968). These descriptions were accurate enough for Brusa et al. (2009) to identify the specimen from Patagonia as T. brocchii and the specimen from Mar del Plata as well. Thysanozoon brocchii has been described inhabiting Indopacific waters, the Mediterranean, and the Atlantic coast of South America, from the Caribbean to Patagonia. Such a worldwide distribution is curious, especially since water temperature has been considered a limiting factor for the distribution of polyclad species. Prudhoe (1985) proposed that the presence of dorsal papillae in the genera Acanthozoon and Thysanozoon could be related with their flotation capacity as a mean of dispersion, but from personal observation, T. brocchii possess a benthonic life habit, crawling over rocks and into cracks between short swimming periods. Faubel (1984) published a list of pelagic polyclad species collected during different expeditions to South and Central Atlantic Ocean and Sargasso Sea. The unpapillate polyclads collected by these expeditions, were not in accordance to Prudhoe’s (1985) hypothesis. We agree with Brusa et al. (2009) in that the presence of the papillae should be associated with increasing the surface of gas exchange and digestion. The cosmopolitan dispersion of T. brocchii over the South American Atlantic coasts could be associated with the Brazilian ocean current, especially at larval stage. However, because the traditional taxonomy of the Pseudocerotidae is mostly based on external morphological characters, it does not necessarily reflect their phylogenetic relationships. There is still no molecular evidence to discuss if the South American T. brocchii is genetically identical with the morphologically similar specimens collected from the Indopacific waters and Mediterranean coasts.Published as part of Bulnes, Verónica N., Albano, Mariano J., Obenat, Sandra M. & Cazzaniga, Néstor J., 2011, Three Pseudocerotidae species (Platyhelminthes, Polycladida, Cotylea) from the Argentinean coast, pp. 30-44 in Zootaxa 2990 on pages 35-38, DOI: 10.5281/zenodo.20231