Epigamia charcoti ( Gravier, 1906 ) Gravier, 1906

Nygren, Arne, 2004, Revision of Autolytinae (Syllidae: Polychaeta)., Zootaxa 680, pp. 1-314 : 169-173

Epigamia charcoti ( Gravier, 1906) comb. n. (Fig. 85A–E)

Autolytus charcoti Gravier, 1906: 283 –285; 1907: 7–8, pl. 1, fig. 1–2, textfigs 1–2; Benham 1921: 27 –31, pl 5, figs 7–10; 1927: 60. Monro 1930: 97; 1936: 131–132, fig. 22; Hartman 1953: 27; 1964: 77, pl. 24, fig. 1; Hartmann­Schröder & Rosenfeldt 1988: 45–46; 1992: 102.

? Autolytus charcoti Fauvel 1950: 758 –759; Wesenberg­Lund 1961: 97; Knox & Cameron 1970: 79.

Autolytus (Regulatus) charcoti Hartman 1967: 53 –54.

Not Autolytus charcoti Day 1960: 317 –318; 1967: 283, fig. 12.12K–N (= Procerini sp).

Material examined. Antarctic Sea: 2 syntypes MNHN A72, Antarctic expedition, 1905.

Diagnosis. Epigamia with long alternating dorsal cirri and a trepan consisting of 27 teeth, 1 large alternating with 2 smaller in 2 rings

Description. Two anterior fragments, length 35–48 mm for 26–44 chaetigers, width 0.45–0.55 mm. Preserved material yellowish brown, no colour markings. Ciliation as 2 trochs per segment, seen in posterior part of larger fragment.

Eyes separated; eye spots absent. Palps in dorsal view projecting 1/5–1/4 of prostomial length, fused. Extension of nuchal epaulettes to end of chaetiger 3 (Fig. 85A).

Median antenna reaching chaetiger 10–14. Lateral antennae and dorsal tentacular cirri, length 2/3 of median antenna. Ventral tentacular cirri 1/3 as long as dorsal pair. First dorsal cirri as long as median antenna. Second dorsal cirri as long as ventral tentacular cirri. From chaetiger 1–27 cirri with usual alternation in direction, more posterior difficult to assess due to lost cirri. Dorsal cirri from chaetiger 3, alternate in length; short cirri equals 1/2–4/5 of body width, long cirri 3/4 to slightly longer than body width. Cirrophores present on tentacular cirri, and all dorsal cirri. Cirrophores equal, cirrostyles unequal (Fig. 85A, B); short cirrostyles 1/2–2/ 3 in length of long cirrostyles; cirrophores shorter than parapodial lobes; cirrophores shorter than cirrostyles. All appendages cylindrical.

Parapodial lobes large, rounded, slightly swollen dorsal to chaetal fascicle (Fig. 85B). Chaetiger 24 with 2 aciculae. Chaetal fascicle with c. 10 compounds in all present chaetigers. Compound chaetae with large distal tooth (Fig. 85D); serration present. Single thin bayonet chaetae (Fig. 85E), beginning between 26–28.

Pharynx with 1 sinuation anterior to proventricle. Trepan in tentacular segment or chaetiger 2, with 27 unequal teeth, 9 large teeth and 18 smaller; 1 large alternating with 2 small, in 2 rings (Fig. 85C). Basal ring present; infradental spines present. Proventricle equal in length to 4–5 segments in chaetiger 6–11 with c. 40 rows of muscle cells (n=2). Pygidium lost.

Reproduction. Epigamy recorded by Benham (1921; 1927) and Monro (1936). The descriptions are sufficiently good for a reliable connection of these epitokes to the atokes of E. charcoti .

Morphology of epitokous stages. Descriptions extracted from Benham (1921).

Male. Length 32 mm for 14+45+20 chaetigers. All appendages more or less brown. Palps small, do not project in front of prostomium. Nuchal epaulettes reaching end of chaetiger 3. Median antenna c. 5 mm in length. Lateral bifid antennae, 1/3 as long as the median antenna; basal part 1/3 of total length, outer ventral rami longer than inner dorsal rami. Frontal processes, equal to 1/2 of prostomium width. First dorsal cirri, longer than median antenna. Alternation in direction of cirri not described. Cirri length not described. Large cirrophores on first dorsal cirri present, other cirrophores not described.

Female. Length 38 mm for 14+40+30 chaetigers. All appendages more or less brown. Dorsal surface of body with intersegmental brown bands. Distinct nuchal epaulettes. Egg sac from behind chaetiger 15.

Habitat. Unknown.

Distribution. Antarctic.

Remarks. Epigamia charcoti is most similar to E. alternata , both taxa have nuchal epaulettes reaching end of chaetiger 3, and long alternating dorsal cirri. The taxa may be separated on the detailed structure of the trepan, as E. charcoti lacks the additional spines at the base of the larger teeth, present in E. alternata .

Epigamia labordai ( San Martín & López, 2002) comb. n. (Fig. 86A–G)

Autolytus labordai San Martín & López, 2002: 136 –139, figs 1A–I, 2A–F; San Martín 2003: 502 – 505, figs 278A–I, 279A–F.

Material examined. Spain: holotype MNCN 16.01/6096a and 56 paratypes MNCN 16.01/6096b, Banco de Galicia, 769–780m, 28 Jun 1991.

Diagnosis. Epigamia with long nuchal epaulettes; compounds with long blades; trepan with teeth in 3 sizes, 1 large alternating with 2 medium or with 1 medium, 1 small and 1 medium.

Description. All material incomplete anterior fragments. Length of holotype 5.6 mm for 50 chaetigers, width 0.6 mm (in paratypes 1.7–2.6 mm for 14–20 chaetigers, width 0.35–0.7 mm). Preserved material yellowish, in some specimens the nuchal epaulettes faintly brown­greenish; eyes dark red. Ciliation not possible to assess (scarce according to original description).

Eyes confluent; eye spots present. Palps in dorsal view projecting 1/4–1/3 of prostomial length, fused at base (Fig. 86B). Extension of nuchal epaulettes from beginning of chaetiger 4 to end of chaetiger 6 (Fig. 86A), divergent after chaetiger 1.

All specimens have lost their median antenna as well as their first dorsal cirri. In a few some part of the lateral antennae left. Dorsal tentacular cirri equal in length to body width, ventral pair and second dorsal cirri 1/2 as long. Alternation in direction of cirri not assessed. Dorsal cirri from chaetiger 3, alternate in length in at least to chaetiger 10, short cirri equals 1/3 of body width, long cirri equals 1/2 of body width. Cirrophores present on tentacular cirri, and all dorsal cirri. Cirrophores equal, cirrostyles unequal; short cirrostyles 2/ 3 in length of long cirrostyles; cirrophores shorter than parapodial lobes; cirrophores shorter than cirrostyles. All appendages cylindrical, including lost anterior appendages ( San Martín & López 2002).

Parapodial lobes large, rounded rectangular. Anterior chaetigers with 3 aciculae, 1–2 in posterior part of fragments. Chaetal fascicle with 12–15 compounds. Compound chaetae with small distal tooth (Fig. 86D); serration present; chaetal blades longer than usual in autolytines. Single thin bayonet chaetae (Fig. 86E), beginning between chaetiger 7–30.

Pharynx with 1 sinuation, anterior and sometimes lateral to proventricle. Trepan in chaetiger 1–2 with 30–34 unequal teeth; 1 large alternating with 2 medium or 1 medium–1 small–1 medium (Fig. 86G); arranged in 2 or 3 rings (uncertain observation). Basal ring present; infradental spines may be present (uncertain observation). Proventricle equal in length to 3–4 segments in chaetiger 8–15 with 31–34 rows of muscle cells. Pygidium lost.

Reproduction. Epigamy. Several of the specimens have eggs from chaetiger 8–9 and backwards. In some of the larger specimens the palps are smaller and directed downwards, the eyes are larger and the anterior pair has moved to a more ventral position (Fig. 86C). In one specimen notopodial aciculae (Fig. 86F) and developing swimming chaetae was found from chaetiger 17 and in the same specimen the proventricle had begun to degenerate. In addition, fig. 2C in the original description shows a male with developing bifurcation on the lateral antennae.

Morphology of epitokous stages. No fully developed epitokous individual found, but see above.

Habitat. 769– 780 m.

Distribution. North East Atlantic. Spain. Only known from type locality.

Remarks. Epigamia labordai , together with E. macrophtalma and E. usaensis Imajima, 1966 , make up one subclade in Epigamia . The clade is supported by a number of apomorphies, e.g. number of different teeth­sizes equals 3 (character 41), and number of rings equals 3 (character 44) (uncertain if 2 or 3 in E. labordai ). Epigamia labordai is most similar to E. usaensis with which it shares the long bent nuchal epaulettes and the long chaetal blades; however, the trepans differ between the two, in E. usaensis there is a regular alternation of 1 large, 1 medium, 1 small and 1 medium tooth, in E. labordai there is not always a small tooth in between the middle­sized teeth. In addition the mediumsized trepan teeth is not fused by two third to the larger teeth in E. labordai as in E. usaensis .

Epigamia macrophtalma ( Marenzeller, 1875) comb. n. (Fig. 87A–E) Proceraea macrophtalma Marenzeller, 1875: 37 –39, pl. 4, fig. 2, 2A–B.

Not Proceraea macrophtalma Langerhans 1879: 579 , fig. 29.

Not Autolytus (Proceraea) macrophtalma Saint­Joseph 1887: 226 –228.

Not Autolytus macrophtalma Southern 1914: 41 ; Allen 1927: 870 –871.

Not Autolytus macrophtalmus Cognetti 1957: 65 –66, fig. 12B.

Autolytus sp Hauenschild 1953: 42 –43, fig. 5.

Autolytus sardai Martin & Alós, 1987: 579 –584, figs 2A–C, 3A–C; San Martín 2003: 498 –500, fig. 276A–E.

Autolytus macrophtalmus Nygren & Sundberg 2003 : GenBank sequences, 18S rDNA partial sequence AF474293 .

Material examined. Italy: 2 syntypes on slides NHMW 2507, Adriatic Sea. France: 9 spms (2 spms in formalin, 6 spms on slides (5 rear ends in author's collection for DNA analyses), 1 spm in author's collection for DNA analyses), Banyuls­sur­Mer, 42°28.6'N 03°09.7'E, dive, 30 m, "coralligene", 26 Apr 2001.

Diagnosis. Epigamia with very large eyes, dorsal cirri from chaetiger 3 flattened and filled with "empty" glands, and a trepan with 36 teeth in 3 sizes, in 3 rings.

Description. Length 1.8–4.8 mm for 20–43 chaetigers, width 0.20–0.30 mm. Live specimens yellow in pharyngeal region, intestinal region orange to brownish (Fig. 87A, B). Dorsal cirri from chaetiger 3 with, what looks like, large empty glands, which gives the cirri a checkered appearance (Fig. 87A, B); eyes red. Ciliation as 1 troch per segment.

Eyes strikingly large, confluent (Fig. 87A, B); eye spots present. Palps in dorsal view projecting 1/5 of prostomial length (Fig. 87A, B), fused at base. Extension of nuchal epaulettes to end of chaetiger 1 (Fig. 87A).

Median antenna reaching c. chaetiger 10–11 (n=5) in live specimens. Lateral antennae and dorsal tentacular cirri, length 1/2–2/3 of median antenna. Ventral tentacular cirri 1/2 as long as dorsal pair. First dorsal cirri as long as median antenna, second dorsal cirri as long as ventral tentacular cirri. Alternation in direction of cirri not assessed. Dorsal cirri from chaetiger 3, of equal length (Fig. 87A), c. 1/2 of body width. Cirrophores present on tentacular cirri, and all dorsal cirri. Cirrophores and cirrostyles equal; cirrophores shorter than parapodial lobes; cirrophores shorter than cirrostyles. Antennae, tentacular cirri, first and second dorsal cirri and anal cirri cylindrical, all other dorsal cirri flattened.

Parapodial lobes of medium size, rounded. Anterior chaetigers with 2–3 aciculae, 1–2 in median and posterior. Chaetal fascicle with 6–11 compounds in anterior chaetigers, 4–6 in median and posterior. Compound chaetae with small distal tooth; serration present (Fig. 87D). Single thin bayonet chaetae (Fig. 87E), beginning between chaetiger 2–11.

Pharynx with 1, 2 or 3 sinuations anterior and lateral to anterior half of proventricle (Fig. 87A). Trepan in chaetiger 1 (Fig. 87A), with 36 unequal teeth in 3 rings, in outer view 9 large alternating with 18 median and 9 smaller (n=6) (Fig. 87C). Basal ring present; infradental spines absent. Proventricle equal in length to 1.5–2 segments in chaetiger 7–9 (Fig. 87A) with 16–18 rows of muscle cells (n=4). Anal cirri equal in length to 1–1.5 times body width.

Reproduction. Epigamy, concluded from circumstantial evidence. Several of the examined specimens are females with eggs from just behind (Fig. 87B) and at the sides of the proventricle, in two of these specimens one can also see that the parapodia behind chaetiger 14 are larger and are developing notopodial lobes. However, no swimming chaetae could be detected. One of the specimens is also found to have larger eyes and smaller palps, indications of a transition to an epigamic state. The strange "chimaera" described by Hauenschild (1953) from a photograph taken by Hartmann, is most likely a female of E. macrophtalma entangled with a posterior end of another individual of male sex. Eggs are found as far forward as chaetiger 5.

Habitat. Coralligene, subtidal.

Distribution. Mediterranean.

Remarks. Epigamia macrophtalma is easily recognized on its large eyes, flattened cirri, and trepan structure. Its trepan is very similar to E. usaensis ', but in E. usaensis , the middle­sized teeth are fused with the large tooth. Epigamia macrophtalma may be separated from E. labordai and E. usaensis on its shorter nuchal epaulettes reaching only end of chaetiger 1, its flattened cirri, and its generally more convoluted pharynx. None of the previous records of E. macrophtalma by earlier authors appear to be correct. Although it is not evident which species they refer to, E. macrophtalma can be excluded. Their " A. macrophtalma " is a species with 20 equal teeth that have a schizogamous reproduction. The trepan structure is difficult to see, and even Marenzeller himself did not give an accurate description, which is a cause to the confusion. The description of Autolytus sardai agrees in every detail with E. macrophtalma .