Anthocephalum machadoi Sakai, Marques & Trevisan, 2025, n. sp.
Creators: name: Sakai, Lilian F.
name: Marques, Fernando P. L.
name: Trevisan, Bruna
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Platyhelminthes
Cestoda
Rhinebothriidea
Anthocephaliidae
Anthocephalum
Anthocephalum machadoi

description: Anthocephalum machadoi n. sp.,
Family Anthocephaliidae, order Rhinebothriidea
(Figs. 3A, 4A–C, 5A–E, 6A–B)
Type host: Hypanus guttatus (Bloch & Schneider) – Longnose stingray.
Type locality: Coast of Maceió, Alagoas, Brazil (09°40’25.32”S, 035°44’07.08”W).
Additional locality: Colares, Pará, Brazil (01 ◦ 00’33.88”S, 048 ◦ 16’47.28”W).
Site of infection: Spiral intestine.
Prevalence of infection: 44.9% (31 of 69 valves).
Specimens deposited: Holotype (MZUSP 8076) and 11 paratypes (MZUSP 8054a–e, 8055, 8056a–b, 8057, 8058, 8059); 12 paratypes (HWML 217938–217949); and, 12 paratypes (LRP 11270–11281).
Etymology: This species honors Dr. Denis Jacob Machado for his contribution to the systematics of cestodes through his expertise in bioinformatics.
Description. [Based on 37 specimens: 29 whole mounts of mature worms, 2 scolexes prepared for SEM and cross sections of 6 mature proglottids]: Worms apolytic, 5.8–13.6 mm (n=29) long with 20–45 proglottids (n=29) in number, maximum width 439.5–761 (n=10) at level of scolex (Fig. 3A). Scolex (Figs. 4B, 5A) with four stalked bothridia, each one with 76–96 (n=10) marginal loculi and one oval apical sucker; apical sucker 33.6–45.1 (n=4) long by 29.5–32.7 (n=4) wide. Short cephalic peduncle present. Proximal surfaces of marginal loculi next to the bothridial rims covered with acicular filitriches and scolopate spinithriches (Fig. 5B, C); bothridial rims and proximal surface of marginal loculi covered with acicular filitriches (Fig. 5D); distal surfaces of bothridia covered with capiliform filitriches (Fig. 5E).
Proglottids slightly craspedote. Immature proglottids wider than long, becoming longer than wide with maturity, 16–42 in number (n = 29) (Fig. 3A). Mature proglottids (Fig. 4A) 1,066–1,749.6 (n=15) long by 125.2–225.3 (n=15) wide, 1–4 in number (n = 29). Testes arranged in two columns from near anterior margin of proglottid to level of genital pore, and 1 row-deep in cross-section (Figs. 4A, 6A). Testes 35.5–72.5 (n=17) long by 28.1–55.8 (n=17) wide, 35–46 (n=17) in number. Cirrus-sac pyriform, bent posteriorly, 75.8–121.3 (n=8) long by 43.8–112.5 (n=8) wide, containing coiled cirrus (Fig. 4C). Cirrus armed with spinitriches. Genital pores lateral, irregularly alternating, 27.6–35.5% (n=15) of proglottid length from posterior end (Fig. 3A, 4A). Ovary near posterior end of proglottid, H-shaped in frontal view (Figs. 4A), tetralobed in cross-section (Fig. 6B), slightly asymmetrical, 229.6–432 (n=16) long by 68–165.8 (n=16) wide; ovarian bridge near middle of ovary. Mehli’s gland immediately posterior to ovarian bridge. Vagina thick-walled, sinuous, extending medially in proglottid from ootype to anterior margin of cirrus-sac, then laterally to open into genital atrium anterior to cirrus (Fig. 4C). Vitellarium follicular; vitelline follicles 13.6–33.1 (n=17) long by 6.5–17.3 (n=17) wide, arranged in two lateral bands, each band consisting of one dorsal and one ventral column of vitelline follicles, extending from near anterior margin of the anterior-most row of testes to near posterior margin of proglottid, interrupted by genital pore and ovary both dorsally and ventrally (Figs. 4A, C). Uterus saccate, ventral, extending along median line of proglottid from near the ovarian bridge to posterior margin of first or second anterior-most row of testes (Fig. 4A).
Remarks: Anthocephalum machadoi n. sp. is distinguishable among the 24 other species of the genus Anthocephalum by its distinct combination of morphological features which include: 35–46 testes, 76–96 loculi, a total length of 5.8–13.6 mm, and vitelline follicles organized into two lateral bands with one dorsal and one ventral column each. In comparison with Anthocephalum blairi Herzog & Jensen, 2018, Anthocephalum gravisi Herzog & Jensen, 2018, Anthocephalum haroldsoni Herzog & Jensen, 2018, and Anthocephalum papefayei, the new species possesses more marginal loculi (76–96 vs. 65–73, 43–52, 41–57, and 45–60; respectively). On the other hand, Anthocephalum machadoi n. sp. posses fewer marginal loculi compared to Anthocephalum gracile (Wedl, 1855) Ruhnke, 1994, Anthocephalum healyae Ruhnke, Caira & Cox, 2015, Anthocephalum lukei Ruhnke and Seaman, 2009, Anthocephalum meadowsi Ruhnke, Caira & Cox, 2015, Anthocephalum odonnellae Ruhnke, Caira & Cox, 2015, Anthocephalum philruschi Ruhnke, Caira & Cox, 2015, Anthocephalum cairae, and Anthocephalum hobergi (Zamparo, Brooks & Barriga, 1999) Marques & Caira, 2016 (76–96 vs. 116–121, 150–171, 107–138, 98–134, 135–159, 200–219, 197–198, and 100; respectively).
Anthocephalum machadoi n. sp. differs from Anthocephalum duszynskii Ruhnke, 1994 and Anthocephalum mounseyi Herzog & Jensen, 2018, in its total length (5.8–13.6 mm vs. 18–31 and 2.6–3.4 mm, respectively), and from Anthocephalum decrisantisorum Ruhnke, Caira & Cox, 2015, Anthocephalum jensenae Ruhnke, Caira & Cox, 2015, Anthocephalum ruhnkei Herzog & Jensen, 2018, and Anthocephalum centrurum, in number of testes (35–46 vs. 17–24, 14–20, 22–34, and 48–78, respectively). In comparison with Anthocephalum alicae, A. machadoi n. sp. possesses more proglottids in number (20–45 vs. 9–15, respectively).
There are only five species— Anthocephalum currani Ruhnke & Seaman, 2009, Anthocephalum michaeli Ruhnke & Seaman, 2009, Anthocephalum jeancadenati Boudaya, Neifar & Euzet, 2018, Anthocephalum kingae (Schmidt, 1978) Ruhnke & Seaman, 2009, and Anthocephalum mattisi — that closely resembles A. machadoi n. sp. in number of marginal loculi, number of testes, total length, and proglottid number. However, they can be distinguished based on the position and number of the vitelline follicles. Anthocephalum machadoi n. sp. possesses vitelline follicles organized into two lateral bands with single dorsal and ventral column. In contrast, A. michaeli, A. jeancadenati, A. kingae, and A. mattisi also possess vitelline follicles in two lateral bands but with 2–3 dorsal and ventral columns. Finally A. currani possesses vitelline follicles in two lateral bands with 3–5 dorsal and ventral columns.
description: Published as part of Sakai, Lilian F., Marques, Fernando P. L. & Trevisan, Bruna, 2025, Diversity and phylogenetic position of the amphi-American lineages of the tapeworms of the genus Anthocephalum Linton, 1890 (Rhinebothriidea: Anthocephaliidae), pp. 151-178 in Zootaxa 5584 (2) on pages 159-162, DOI: 10.11646/zootaxa.5584.2.1, http://zenodo.org/record/14830734