Gieysztoria duopunctata, Reyes & Binow & Vianna & Brusa & Martins, 2021

Reyes, Jhoe, Binow, Daniela, Vianna, Rogério T., Brusa, Francisco & Martins, Samantha E., 2021, Fig. 12. Majella pristis n in Periclimenaeus djiboutensis Bruce 1970, Zoological Studies 60 (22), pp. 1-33 : 18-26

Gieysztoria duopunctata n. sp. Reyes and Brusa

( Figs. 8–10 ) urn:lsid:zoobank.org:act:F2160DDB-6595-4E08-B8EB-023021FF140F

Studied material: Holotype: one mounted specimen ( MZUSP PL 2210 ) . Paratypes: fifteen mounted specimens (MZUSP PL 2197–2209, 2211, 2212).

Type locality: Site 3 (32°50'11.42"S; 52°38'37.45"W) (18/02/2019; 5/06/2019), associated with phytal microhabitats at the ESEC Taim.

Another locality: Site 2 (15/03/2019), associated with phytal microhabitats

Etymology: The specific name is originating from Latin, duo (two) and punctata (tip, point) The name refers to the dorsal spines located at both sides of the edges of the girdle, which are small, and different in length, one smaller than the other.

Diagnosis: Crown-shaped stylet ± 43.1 μm long, comprises a fibrous-like girdle with a distal reinforced ring from which 12–18 spines of different lengths and widths arises. Spines gradually get longer along the rim of the girdle until the opposite region of the girdle opening. In this area, spines are the longest and the widest.

Description: Body 791.2 ± 101.8 μm (650.9–945.3 μm; n = 11) long and 157.4 ± 36.75 μm (120–257.6 μm; n = 11) wide, rounded form (flattened whole-mounted) to elliptical; anterior region with a rounded end and caudal region tapering caudally abruptly, composed by a tail-like with 5–6 finger-like adhesive papillae ( Fig. 10A–B ). Body orange browndarkish pigmentation (live adults), it can be seen spotted along the body or dispersed, but some spots are especially concentrated behind the pharynx ( Fig. 8A–C ). Also, brown narrow longitudinal stripes along the body are seen in the biggest animals ( Fig. 8D ). Ciliated epidermal cells are polygonal in shape; rigid cilia not observed. Rhabdites are arranged in groups of 3–6 over the body surface. The brain is comprised of two globular ganglia from which lateral nerves extend towards the posterior region of the body, situated ventrally to the eyes. Black bean-shaped eyes located dorsally at the anterior region of the body; they are separated from each other by 44.5 ± 9.7 μm (31.2– 58.4 μm; n = 11) ( Figs. 8A–C , 10A ). Mouth ventral, subterminal. Doliiformis pharynx (see Luther 1955), 140.7 ± 19.3 μm (108.2–170.6 μm; n = 11) long and 103.7 ± 9 μm (85.5–117.1 μm; n = 11) wide ( Figs. 8A–C , 10A ).

Male reproductive system posterior in the half body region and it is composed of testes, deferent ducts, seminal vesicle, prostatic vesicle, and penis stylet. Paired testes, 183 ± 50.4 μm (127.5–280.5 μm; n = 9) long and 28.3 ± 7.6 μm (21.6–40.4 μm; n = 7) wide, located at the posterior 1/3 of the body, at both sides of the body ( Figs. 8A–B , 10A ). Deferent ducts pair, thin and short, from the lateral-rostral region of the testes until connecting one in each side of the seminal vesicle ( Figs. 8E , 10A–B ). The globular seminal vesicle is 40.3 ± 5.5 μm (34.7–47.8 μm; n = 4) long and 47.5 ± 5.2 μm (41.3–53.3 μm; n = 4) wide. Prostatic vesicle is 31.8 ± 1.9 μm (30–34.14 μm; n = 4) long and 49.6 ± 6.4 μm (43.2–58.2 μm; n = 4) wide, globular with thickwalls, ( Figs. 8A, E , 10A–B ); saccular glands present, associated to the proximal region. Also, the prostatic vesicle is more voluminous than the seminal vesicle in mature animals ( Figs. 8E , 10B ). Distally, the prostatic vesicle is continued by a sclerotic penis stylet. The crown-shaped stylet, 43.1 ± 3 μm (37.6–47.7 μm; n = 14) long, comprises a well-defined fibrous-like girdle that has a distal reinforced ring from which 12–18 spines of different lengths and widths arises ( Fig. 9B ). The dorsally-opened girdle is 14.3 ± 2.2 μm (11–18.71 μm; n = 14) in height and 27.7 ± 3 μm (20.8–331.8 μm; n = 16) in width. Also, the girdle is 56.8 ± 5.3 μm (54–64.67 μm; n = 4) in circumference. In addition, the girdle is higher where the longest spines arise and gradually reduces in height as the spines shorten ( Fig. 10C–D ). Spines are fang-shaped with a long and broad funnel-shaped base, from caudal-transverse view, spines take the form from rectangular to quadrangular shape ( Fig. 9A ). The two smaller spines measure: 13.9 ± 3 μm (8.6–19 μm; n = 15) long and 4.3 ± 1.3 μm (2.3–6.3 μm; n = 12) wide; 19 ± 3.8 μm (13.3–23.4 μm; n = 8) long and 5.5 ± 2.7 μm (3.2–9.8 μm; n = 8) wide. Spines gradually get longer along the rim of the girdle until the opposite region of the girdle opening. In this area, spines are the longest (27.3 ± 4 μm (15.3–31.9 μm; n = 15)) and the widest (5 ± 1.4 μm (3.7–9.1 μm; n = 13)) ( Figs. 9A–B , 10C–D ). The width of the spines was measured from its base.

Ovary single, saccular, in the left posterior 1/3 region of the body, posterior to the intestine ( Figs. 8A, E , 10A–B ), followed by a narrow oviduct associated to the seminal receptacle. The seminal receptacle connects to the uterus by the female duct. The uterus may contain one egg. Egg 166 ± 5.2 μm (162.2–171.9 μm; n = 3) long and 112 ± 5.5 μm (108.3–118.3 μm; n = 3) wide, oval, brown-yellowish ( Fig. 10B ). Copulatory bursa has thick walls, united to the uterus by distal region, both discharge on the common genital atrium which leads to the gonopore ( Figs. 8E , 10A–B ). Gonopore approximately on the 1/3 of the body length. Vitellaria 331.4 ± 75.3 μm (214.5–408 μm; n = 6) long, paired (smooth), dark greenish; filling in dorsoventrally the region comprising from the posterior end of the pharynx toward the ovary, where it forms a “V”-shaped common duct ( Figs. 8B , 10A–B ).

Taxonomic remarks: Within Gieysztoria , species are grouped as Aequales and Inaequales following Luther’s (1955) criteria. The first group has spines with similar shapes and sizes, while the latter, has spines with different sizes and shapes. Further, Inaequales is subdivided into Falcatae (with a large, robust falcate stylet spine, and a variable number of plate-like spines), Fenestratae (girdle with one or more openings in the girdle), Radiatae (stylet with symmetrical morphology) and Aberrantes (stylet with an aberrant configuration) ( Luther 1955; Van Steenkiste et al. 2012). Gieysztoria duopunctata n. sp. belongs to the Inaequales, subgroup Radiatae. Seven species resemble G. duopunctata n. sp., namely: G. bergi (Beklemischev, 1927) , G.coronae Noreña-Janssen, 1995 , G. foreli ( Hofsten, 1911) , G. pseudodiadema Noreña-Janssen, 1995 , G. pulchra Wang and Deng, 2006 , G. reggae Therriault and Kolasa, 1999 and G. tigrensis Noreña-Janssen, 1995 . The stylet lengths of G. coronae , G. pseudodiadema and G. tigrensis were taken from figures in the respective descriptions, while the rest of the stylet lengths were obtained from the measurement mentioned by the respective author of each species. It is possible to differentiate G. duopunctata n. sp. from other Radiatae species due to several features. Gieysztoria foreli and G. reggae present in the girdle a distal ring joined with several bridges and spines of similar shape or size, 15– 22 and 8–12, respectively ( Luther 1955; Therriault and Kolasa 1999; Lu et al. 2013). Gieysztoria tigrensis has a bigger stylet length (363.6 μm); this species has spines with remarkable differences in length and configuration ( Noreña-Janssen 1995). Contrary, G. duopunctata n. sp. has a small stylet (43.1 μm long) with 12–18 fang-like spines of variable lengths. The stylet length of G. pulchra (48 μm) is bigger than those of G. duopunctata

n. sp. (43.1 μm). Also, G. pulchra has two long lateral spines on the edges of the girdle, while G. duopunctata n. sp. has two small (but different in size) spines on the edges of the girdle. The total number of spines of G. duopunctata n. sp. are 12–18, notably differentiated from G. pulchra which has 13 spines ( Wang and Deng 2006). The stylet length of G. duopunctata n. sp. (43.1 μm) is similar to G. pseudodiadema (43.8 μm) ( Noreña-Janssen 1995). However, G. pseudodiadema has seven empty spines, spines at the left side are well-developed, while those at the right side are reduced ( Noreña-Janssen 1995). So, G. pseudodiadema differs from G. duopunctata n. sp. owing to the number of spines and stylet configuration. Gieysztoria coronae has a ~41.2 μm long stylet with 25–26 similar-in-length spines, these spines are hollow and triangular in shape when observed in cross section ( Noreña-Janssen 1995). Contrary, G. duopunctata has a 43.1 μm long stylet with 12–18 fang-like different-in-length spines, spines are quadrangular in shape when observed in cross section. Also, two small spines (one a bit longer than the other) arise from the edges of the girdle of G. duopunctata n. sp. As for G. bergi , this species has a 107 μm long stylet, 24 spines similar in length (30 μm) and are quadrangular in shape (Beklemischev 1927; Luther 1955; Lu et al. 2013). These features are not seen in G. duopunctata which has a small stylet (43.1 μm long), 12-18 fang-like different-in-length spines and two spines notoriously different in size at the dorsal edges of the stylet. Therefore, the above-mentioned differences, mainly on the penis stylet morphology, indicate that individuals found in the ESEC Taim represent a new species within Gieysztoria .

Distribution: Southern Brazil, Rio Grande do Sul state, Taim strict nature reserve (ESEC Taim).

Gieysztoria hermes n. sp. Reyes and Brusa ( Figs. 11–12 ) urn:lsid:zoobank.org:act:F98ED003-EAE2-4DB7-A16A-C73AE5C9B9B1

Studied material: Holotype: one mounted specimen ( MZUSP PL 2213 ) . Paratypes: five mounted specimens (MZUSP PL 2214–2218).

Type locality: Site 1 (32°33'18.07"S; 52°31'18.50"W) (19/11/2018), associated with benthal microhabitats at the ESEC Taim.

Another locality: Site 1 (19/11/2018), associated with benthal and phytal microhabitats at the ESEC Taim.

Etymology: The name of this species is originated from the name of the Greek Olympian god Hermes. This deity is usually depicted using the petasos, a widebrimmed hat, but with a pair of small wings, which resembles the stylet morphology of this species when observed upside down.

Diagnosis: Stylet with a dorsally-opened fibrous girdle. The girdle has five different groups of spines: two groups of rows of spines (a and b) arising from the dorsal edges of the girdle, and three ventral spines. Spines from group a are a dorsal protrusion of the girdle, which bears several rows (toothbrush-like) of spines. Proximal spines are longer and have broader hollow bases, these spines gradually get shorter and thinner as spines reach its distal end. Spines from group b are a dorsal protrusion, distally, has several rows with a great number of very thin and short spines. Within the three ventral spines, the central one is the largest and strongest. The remaining flanking spines are shorter, but different in length.

Description: Body 798.6 ± 164.4 μm (509.5–923 μm; n = 5) long and 225.2 ± 55.2 μm (164.4–304.6 μm; n = 5) wide; habitus typical of the genus, rounded anterior end, widening towards the middle region of the body, elongated and narrowed at the end where it bears 5–6 finger-like adhesive papillae ( Fig. 11C–D ). Orangebrown pigment in vivo, randomly dispersed all over the body ( Fig. 11A–C ). Body surface with several rhabdites and ciliated epidermal cells, rigid cilia not distinguished. Eyes, one pair, black kidney-like, in the anterolateral region, separated by 55.8 ± 4.35 μm (50.5–61 μm; n = 4) ( Fig. 11A, D ). Brain under the eyes. Mouth subterminal, ventral at the anterior region of the body. Mouth followed by a dolliform pharynx, 162.8 ± 18.4 μm (137.7–182 μm; n = 4) long and 125.6 ± 12.6 μm (112.2–140.2 μm; n = 4) wide ( Fig. 11A, C– D ).

Ellipsoidal testes are 215.7 ± 50.7 μm (144.7–317.2 μm; n = 10) long and 37.5 ± 12.6 μm (26.4–63.1 μm; n = 8) wide, paired laterally. Deferent duct thin, paired, and extend from the anterior region of the testes, connecting these to the seminal vesicle ( Fig. 11B, E ). Seminal vesicle, 33 ± 10.5 μm (22–42.6 μm; n = 4) long and 41.5 ± 17.7 μm (25.1–59.3 μm; n = 4) wide, globular-shaped; circular notch in the posterior central region ( Fig. 11B, E ), distally connected to a prostatic vesicle. Prostatic vesicle 30.4 ± 9.7 μm (21.9– 39 μm; n = 4) long and 36.3 ± 13.7 μm (22.8–50.5 μm; n = 4) wide, globular, with lateral external glands associated; distally is continued by a sclerotic penis stylet ( Fig. 11B, E ). Stylet is 34.2 ± 3.5 μm (29.1–37.6 μm; n = 6) in axial length; is composed, proximally, by a dorsally-opened fibrous girdle, 24.8 ± 7.3 μm (19.4–39 μm; n = 6) in width and 11.5 ± 2.1 μm (9.1–14.7 μm; n = 6) in height, may present an oval fenestra associated to the strongest distal spine. Distally, the girdle presents five different groups of spines: two groups of rows of spines (a and b) arising from the dorsal edges of the girdle and three spines (blue-, red- and green-colored spines) ( Fig. 12C ) arising from the ventral side ( Fig. 12A–C ). Spines from the group a, comprise a dorsal protrusion of the girdle, 26.7 ± 2 μm (23.3–28.3 μm; n = 6) long, which bears several rows (toothbrush-like) of spines. Proximal spines are longer (10.8 ± 1.6 μm (8.6–13 μm; n = 6)) and have broader hollow bases, these spines gradually get shorter and thinner as spines reach its distal end (shortest spines are 3.7 ± 0.8 μm (2.4–4.4 μm; n = 6)) ( Fig. 12C : a). Spines from group b, comprise a dorsal protrusion which, distally, has several rows with a great number of very thin and short spines. These spines gradually align and lengthen towards its proximal area where they form a comb-like structure ( Fig. 12C : b). A fang-shaped spine (colored in red) is 20.7 ± 1.7 μm (18.5–23.3 μm; n = 6) long, is curved, with a rounded distal tip outward. This is the largest and strongest spine, at the ventral median side of the girdle. Proximally, this spine has a large base (6.8 ± 0.9 μm (5.2–7.9 μm; n = 6) wide) for muscular insertion ( Fig. 12C : red). The other fang-shaped spine (colored in blue) is 16.8 ± 1.5 μm (15–19.1 μm; n = 6) long, is slightly curved outwards, and is located between red spine and spines from the group a. Proximally, it presents a broad base for muscular insertion. Distally, it has a blunt tip. Also, a blue spine is associated with spines from the group a ( Fig. 12C : blue). Spine (colored in green) is 11.9 ± 1.2 μm (10.4–13.5 μm; n = 6) long, blade-like, between red spine and spines from group b. Besides, the green spine is very close to spines from group b ( Fig. 12C : green).

The ovary is ± 127.3 μm long, single sac-like, at the right side of the body, posteriorly to the intestine and continued by the oviduct ( Fig. 11B, E ). Copulatory bursa thick-walled, releasing the contents to the common genital atrium. Seminal receptacle with sperm. Gonopore at the posterior 1/3 of the body. Vitellaria are 303.7 ± 613 μm (210.7–371.8 μm; n = 8) long, paired, smooth dark-greenish, from the posterior side of the pharynx to the end of the intestine, where they join forming a common duct ( Fig. 11C–D ).

Ta x o n o m i c re m a r k s: B e c a u s e o f i t s s t y l e t morphology, Gieysztoria hermes n. sp. belongs to the Inaequales group, subgroup Aberrantes ( Luther 1955). Eight species with similar stylet configuration (aberrant morphology) resemble to the new species, namely, G. atalaya Brusa et al., 2008 , G. complicata ( Fuhrmann, 1914) , G. falx Brusa et al., 2003 , G. intricata ( Marcus, 1946) , G. kasasapa Damborenea et al., 2005 , G. matilde Brusa et al., 2008 , G. namuncurai Damborenea et al., 2007 and G. therapaina ( Marcus, 1946) . However, the features of these species are different from individuals of the new species. Gieysztoria atalaya has a stylet which is twice as long (62 μm) to that of G. hermes n. sp. (34.2 μm). Moreover, G. atalaya possesses a 23 μm-long solitary spine (a) located between the two groups (b and c) of complex spines (a, b and c sensu Brusa et al. (2008)). While G. hermes n. sp. has three ventral spines, being the longest 20.7 μm. In addition, complexes of spines protruding from the girdle in G. hermes n. sp. are different from G. atalaya in number and spine configuration ( Brusa et al. 2008). Gieysztoria falx is differentiated from G. hermes n. sp. due to the former species has two strong pincer-like spines, while the latter has three spines, spine configuration from the protrusion of the girdle are even dissimilar. Also, the stylet of G. falx is larger than G. hermes n. sp. (85–88, 78.9 μm, and 34.2 μm respectively) ( Brusa et al. 2003; Reyes et al. 2019). The stylet of G. complicata and G. intricata are larger than G. hermes n. sp. (100 μm, 120 μm and 34.2 μm respectively) ( Luther 1955; Marcus 1946). Moreover, G. complicata has two strong parallel curved spines outwards (a), a convergent similar-in-shape crown of spines (b) and a “brush” composed of spines (c) (proximal spines longer and broader than distal ones) (a, b and c sensu Marcus (1946)). Also, G. intricata has a single strong verycurved spine inwards with a sharp tip, this spine also bears “cuticular hairs”(a). Group complexes of spines in G. intricata are convergent with different lengths and orientations (b), palisade-like spines (c), and a spine associated to the palisade-like structure (d) (a, b, c and d sensu Marcus (1946)). Those structures are not present in G. hermes n. sp. and they are different. Gieysztoria kasasapa has a 75–85 μm long stylet with two groups of complexes of spines separated by a robust sclerotic arc. The first group is composed of four-convergent rows of spines, each row with 6 to 10 spines. The second group is composed of five straight and hollow spines (18–24 μm long) associated with a long (44 μm) hollow spine orientated outwards ( Damborenea et al. 2005). Gieysztoria hermes n. sp. has no arc that separates the two-complex group of spines, three distal spines are observed instead of the longest one of G. kasasapa . In addition, spines originated from the protrusion of G. hermes n. sp. have a different configuration than those of G. kasasapa . The 54–65 μm-long stylet of G. matilde has a unique hollow blade-like spine (25 μm long) ( Brusa et al. 2008), while G. hermes n. sp. shows three spines of different lengths and shapes, being the longest 20.7 μm. Moreover, G. matilde bears two groups of complexes of spines, each group with several rows of hollow and acicular spines ( Brusa et al. 2008); instead of several rows of spines in a toothbrush-like structure or comb-like arranged spines seen in G. hermes n. sp. Gieysztoria namuncurai has a 100 μm-long stylet with two strong curved saber-like spines (85 μm and 57 μm, respectively) oriented outwards ( Damborenea et al. 2007), while G. hermes n. sp. has a shorter stylet and bears three smaller spines (20.7, 16.8 and 11.9 μm, respectively). In addition, G. namuncurai bears three different groups of spine complexes with different widths, lengths and orders. Gieysztoria hermes n. sp. has only two groups of spine complexes, being spines from the group a notoriously different with its toothbrush-like structure.

The most similar species to G. hermes n. sp. is G. therapaina . This species has a 33 μm-long stylet with a discontinued girdle. Distally to the girdle, G. therapaina , has four groups of spines ( Marcus 1946). Contrary, G. hermes n. sp. has a fibrous continued girdle and bears two groups of complexes of spines and three different-in-length ventral spines. These differences are remarkable when comparing the single strong spine (20 μm long) which is curved in G. therapaina ( Marcus 1946) . The new species has, instead, three ventral spines, being the central one (red) the largest (20.7 μm) and strongest (6.8 μm width). Also, G. hermes n. sp. lacks the projection originating at the distal part of the girdle that has several small spines on its apical portion as it is seen in G. therapaina (the “pente pedunculado” sensu Marcus (1946)). Instead, the new species has a long protrusion which bears several rows (toothbrush-like) of spines; their proximal hollow spines have longer and broader dimensions, these spines gradually get shorter and thinner as spines reach its distal end. Besides, G. therapaina shows thin spines arranged in a single row (c and d sensu Marcus (1946)), whereas in G. hermes n. sp. the distal protrusion of the girdle (spines from group b) has several rows with a great number of very thin and very short spines. These spines gradually align and lengthen forming a comb-like structure. Therefore, the noteworthy features of specimens from the ESEC Taim allow us to propose that they are a new species within Gieysztoria .

Distribution: Southern Brazil, Rio Grande do Sul state, Taim strict nature reserve (ESEC Taim).

Figures

Fig. 8. Live specimens of Gieysztoria duopunctata Reyes and Brusa n. sp. (A) Internal organisation from a live animal based on a whole-mounted preparation, dorsal view. (B) Habitus from live animal, dorsal view. (C) Detail of the anterior region of the body. (D) Detail of the epidermis surface, ventral view (anterior region of the body oriented at the left side). (E) Posterior body region with details of the copulatory organs.

Fig. 9. Gieysztoria duopunctata Reyes and Brusa n. sp. Penis stylet in different focal planes. (A1–6) caudal view and (B1–6) lateral view (same scale bar for all photographs in A and B, respectively).

Fig. 10. Gieysztoria duopunctata Reyes and Brusa n. sp. (A) Schematic representation of the habitus from a live animal based on a whole-mounted preparation, dorsal view. (B) Detail of the male and female copulatory systems, dorsal view. (C) Schematic representation of a squashed stylet. (D) Penis stylet (from the holotype).

Fig. 11. Gieysztoria hermes Reyes and Brusa n. sp. (A) Detail of the anterior region of the body. (B) Posterior body region with details of the copulatory organs. (C) Habitus from live animal, dorsal view. (D) Schematic representation of the habitus from a live animal. (E) Schematic representation of the male and female copulatory systems.

Fig. 12. Gieysztoria hermes Reyes and Brusa n. sp. (A 1–6) Penis stylet in different focal planes (same scale bar for all photographs). (B) Schematic representation of the penis stylet. (C) Graphic explanation of dorsal spines: group a and b, and ventral spines: blue, red and green spines.