Hesione panamena Chamberlin, 1919

Salazar-Vallejo, Sergio I., 2018, Revision of Hesione Savigny in Lamarck, 1818 (Annelida, Errantia, Hesionidae), Zoosystema 40 (12), pp. 227-325 : 279-283

Hesione panamena Chamberlin, 1919 reinstated ( Figs 33 , 34 )

Hesione panamena Chamberlin, 1919: 188-190 , pl. 22, figs 9, 10. — Treadwell 1937: 149.

Hesione intertexta – Hartman 1940: 212, pl. 33, figs 30, 31 (partim, non fig. 30). — Monro 1928: 79; 1933: 26. — Kudenov 1975: 78 (non Grube, 1878).

Hesione genetta – Fauvel 1941: 9 (non Grube, 1867).

Hesione pantherina – Fauvel 1941: 9 (non Risso, 1826).

TYPE MATERIAL. — Eastern Tropical Pacific , Panama. Holotype, USNM 19379, RV Albatross, unnumb. Sta., Perico Island (08°55’00”N, 79°31’00”W), shore, 12.III.1891.

ADDITIONAL MATERIAL. — Eastern Tropical Pacific, Panamá. 2 specimens, BMNH 1928.9.13.54/55, Taboga Island (08°47’00”N, 79°33’00”W), 8-10 m depth, 8.II.1916, T. Mortensen coll. [both complete, one lateraly bent; left parapodia of chaetigers 8 and 10 (one of each specimen) previously removed; body 28-29 mm long, 3-4 mm wide; anterior eyes twice larger than posterior ones, darker in larger specimen; acicular lobe single, tapered, variably contracted; if fully extended, about 1/3 as large as neurochaetae] . — 1 specimen, BMNH 1932.12.24.130, Balboa (08°57’N, 79°34’W), St. George Pacific Expedition, 1923-1924, C. Crossland coll. [complete, splendid, body 46 mm long, 5.5 mm wide; anterior eyes slightly larger than posterior ones; acicular lobe single, tapered, if fully extended, about 1/3 as large as neurochaetae; pharynx fully exposed, dorsal papilla round] . — 2 specimens, ZMUC 2423, Taboga Island (08°47’00”N, 79°33’00”W), 8-10 m depth, 8.II.1916, T. Mortensen coll. [one complete 21 mm long, 3 mm wide; the other reduced to fragments; colorless, acicular lobe single, tapered] .

Western Baja California Sur. 1 specimen, LACM 85732, RV Velero IV, Sta. 2024 (27°48’33”N, 114°42’30”W à 27°49’00”N, 114°42’09”W), 30 km E off Punta Eugenia, 16 m depth, rocks and sand, 18.IV.1951 [35 mm long, 4 mmm wide; upper acicular lobes tapered or digitate, 4-6 times longer than rounded lower ones] . — 1 specimen, LACM 8556, Punta Abreojos (26°42’N, 113°35’W), Knelpen shoal, 18 m depth, in kelp holdfast, 2.III.1959, D. Miller coll. [21 mm long, 5 mm wide; dehydrated, compressed, ventrally bent; pharynx exposed, prostomium collapsed; acicular lobe double, upper one tapered, very long, lower one rounded, short; two neuraciculae; neurochaetal blades bidentate, subdistal tooth small, guard approaching distal tooth] .

Gulf of California. Baja California. 1 specimen, LACM 8565, RV Velero III, Sta. 719 (30°53’00”N, 114°28’35”W), Consag Rock, 18-45 m depth, basket stars, 24.III.1937 [48 mm long, 6 mm wide; laterally bent; antennae minute, as long as interocular distance; longest tentacular cirri reach chaetiger 5; upper acicular lobe long, tapered, lower one rounded, barely visible] .

Sonora. 1 specimen, LACM 8569, Punta Cholla , Puerto Peñasco, 9.V.1941, S. A. Glassell coll. [32 mm long, 4 mm wide; prostomium not collapsed, pharynx partially exposed; several parapodia previously removed; most dorsal cirri on site; upper acicular lobe contracted, digitate, 3-4 times longer than lower one, rounded; in chaetiger 10, left parapodium, upper lobe bifid into two similar sized ones, but placed at the same plane; other parapodia with lobes as indicated before] . — 1 specimen, LACM 8567, Puerto Lobos , 16.IV.1965, P. Pickens coll. [38 mm long, 4 mm wide; partially dehydrated; upper acicular lobe tapered, 4-6 times longer than lower one rounded] . — 1 specimen, LACM 8559, Playa Miramar , Guaymas, 10.II.1948, G. W. & N. MacGinitie coll. [22 mm long, 2.5 mm wide; prostomium with a longitudinal depression throughout its length; most dorsal cirri lost; acicular lobe with upper tine tapered, 4-5 times longer than lower one, rounded] . — 4 specimens, LACM 8562, RV Velero III, Sta. 1042 (28°43’30”N, 112°19’05”W), Turner’s Island , S of Tiburon Island, rocky shore, 24.VI.1940 [macerated, probably very long; neuropodia with a long tapered acicular lobe].

Baja California Sur. Isla Tortuga. 1 specimen, LACM 8571, RV Velero III, Sta. 576 (27°25’30”N, 111°53’25”W), 38 m depth, volcanic sand, 13.III.1936 [27 mm long, 2.5 mm wide; acicular lobe with upper tine tapered, 4-5 times longer than lower rounded ones] .

Bahía Concepción. 2 specimens, ECOSUR 2186 , Laguna Terminal , 1 m depth, rocky bottom, 8.V.1981, R. Ríos coll. [34-40 mm long, 4 mm wide; smaller one with pharynx exposed, without dorsal papilla]. — 3 specimens, LACM 8574, RV Velero III, Sta. 585 (26°43’25”N, 111°54’05”W), Coyote Bay , 3.6-7.2 m depth, sand and kelp, 14.III.1936 [37-38 mm long, 4.5-5.0 mm wide; macerated; pharynx exposed in 1 specimen, margin integument ciliated, partially eroded; chaetal lobe invaginated in many parapodia; acicular lobe with upper tine long tapered, lower one inconspicuous] . — 1 specimen, LACM 8570 , RV Velero III, Sta. 688 (26°41’40”N, 111°51’05”W), 22 m depth, mud and sand, 16.III.1937 [body macerated; pharynx barely exposed; chaetal lobe invaginated in many parapodia; acicular lobe with upper tine tapered, 4-5 times longer than lower one] . — 1 specimen, LACM 8560 , RV Velero IV, Sta. 1771 (26°42’03”N, 111°53’34”W to 26°42’17”N, 111°53’33”W), 13 m depth, rocky bottom, 27.III . — 1 specimen, UANL 641 , 18.VII.1985, J. A. de León-González coll. [5.5 mm long, 1 mm wide; partially dehydrated; pigmentation lost; body cylindrical, pharynx everted, pharynx papilla covered by prostomial anterior margin; prostomium with posterior depression barely visible, eyes not seen; dorsal cirri multi-annulated basally; acicular lobe single, tapered]. — 1 specimen, UANL 642, 20.VII.1985, J. A. de León-González coll. [21 mm long, 3 mm wide; poorly preserved; most integument detached from body wall; cirri macerated; body depressed, parallel sided pharynx invaginated; prostomium with posterior depression visible, eyes visible, brownish, very close to each other, anterior ones slightly more separated and larger than posterior ones; most chaetae lost; posterior end cirri lost].

Bahía de La Paz . 1 specimen, UANL 128, 14.XI.1984, U. Garza coll. [21 mm long, 3.5 mm wide; pharynx everted, dorsal papillae digitate, twice as long as wide; prostomium with posterior depression visible, eyes visible, brownish, very close to each other; dorsal cirri basally multiarticulated; acicular lobe double, upper tine digitate, lower lobe conical, blunt, 1/5 as long as upper one; posterior end cirri lost, anus in an 8-shaped area]. — 5 specimens, LACM 8566, RV Velero III, Sta. 503, off Lighthouse , coralline algae, 9 m depth, 21.II.1936 [19-25 mm long, 2.0- 4.5 mm wide; largest specimen mature (25 mm long, 4.5 mm wide), oocytes about 100 µm; acicular lobe double, upper tine tapered, sometimes basally contracted, 5-8 times longer than lower, rounded one; neurochaetal blades longer in smaller specimens (series of slides and photos in 3 specimens of different length and width)] . — 4 specimens, LACM 8575, RV Velero III, Sta. 1111 (24°21’55”N, 110°15’15”W), San Lorenzo Channel , 11 m depth, sand, shell, coralline, 14.II.1940 [29-41 mm long, 3.5-5.0 mm wide; macerated; chaetal lobes invaginated; acicular lobe with upper tine tapered, 5-8 times longer than lower, rounded one] .

Espíritu Santo Island. 2 specimens, USNM 35566 , 24 m depth, 30.III.1934, E. & C. Berkeley coll. [damaged, most cirri and many chaetal blades lost, partially dehydrated, stiff, many parapodia with longer upper acicular lobe and smaller, rounded lower lobe; not measured to avoid further damage].

A D E B C

San José Island. 2 specimens, MNHN-IA-PNT 91f (formerly jar 70), in different containers; one from the southern lagoon, among corals; the other without precise locality, 1904, L. Diguet coll. [specimen in better condition 24 mm long, 3 mm wide; the other distorted, dried-out; acicular lobe single, can be seen in several parapodia despite their condition; acicular lobes single throughout body] .

Ensenada de Muertos. 1 specimen, LACM 8564 , RV Velero III, Sta. 627 (23°58’55”N, 109°49’25”W), 9 m depth, sand, 5.III.1937 [27 mm long, 2.5 mm wide; many cirri lost; body with circular adsorbed salts throughout the body; acicular lobe with upper tine tapered, long, sometimes digitate, lower one minute ].

Gulf of California, Baja California Sur (?). 1 specimen, MNHN-IA- PNT 91g (formerly jar 70), no locality, 1894, L. Diguet coll. [13 mm long, 2 mm wide; distorted, partially dehydrated, acicular lobes single, can be seen in several parapodia] . — 1 specimen, MNHN- IA-PNT91h (formerly jar 70b), no locality, II.1895, L. Diguet coll. [32 mm long, 4 mm wide; distorted by compression; body almost without pigmentation, one middorsal pale spot between chaetigers 2 and 3]. — 2 specimens, MNHN-IA-PNT 91i (formerly jar 70c), no locality, II.1895, L. Diguet coll. [31-36 mm long, 5-7 mm wide; macerated; both with pharynx fully everted; acicular lobes single] .

Western Mexico. Sinaloa. Sixteen specimens, LACM 7101, Topolobampo (25°36’N, 109°04’W), 26.I.1971, R. C. Brusca coll. [17- 28 mm long, 2-3 mm wide; upper acicular lobe tapered, 4-5 times longer than lower rounded one; 1 specimen mature, 25 mm long, 3 mm wide, dissected for anatomical features]. — 1 specimen, UANL EMU 442, Estero de Urías , Mazatlán, intertidal, 1980, A. Rutgers coll. [11.5 mm long, 2 mm wide; bent ventrally; colorless; acicular lobe single, tapered] .

Nayarit. 1 specimen, LACM 8572, RV Velero III, Sta. 745 (21°54’10”N, 105°53’05”W), Isabel Island , 18-32 m depth, corallines, 2.IV.1937 [37 mm long, 4 mm wide; slightly macerated; acicular lobe rounded, upper tine contracted, 3-4 times longer than lower ones] .

Guerrero. 1 specimen, ECOSUR OH-374, Hornos Beach , Acapulco, on oysters ( Spondylus calcifer ), 4 m depth, 19.IV.2008, L. F. Carrera-Parra & SISV coll. [23 mm long, 3 mm wide; irregular, thin longitudinal lines still visible on tentacular segment only, rest of body colorless; pharynx not exposed; prostomial anterior margin depressed; anterior eyes twice as large as posterior ones; parapodia with acicular lobes single, tapered; posterior end smashed, integument smooth] . — 5 specimens, LACM 8555, RV Velero, Sta. 2596, Santa Lucía bay (16°50’33”N, 99°55’28”W), Acapulco , 2-8 m depth, sponges, algae, rock, muddy sand bottoms, 1.II.1954 [four in better condition, 14-35 mm long, 2.5-5.0 mm wide; dorsal cirri longer than body width, including parapodia; one right parapodium (chaetigers 7-9) removed (kept in container); oocytes 100 µm in diameter] .

Revillagigedo Islands, México. 1 specimen, LACM 134 34, RV Velero III, Sta. 134 (18°20’35”N, 114°44’20”W), 25 m depth, rock, nullipores, 5.I.1934 [extremely distorted, body twisted over itself, posterior region compressed; 17 mm long, 2 mm wide; acicular lobe with upper tine tapered, 4-5 times longer than rounded lower one] . — 1 specimen, LACM 8563 , RV Velero III, Sta. 289 (18°41’50”N, 110°57’20”W), 8-27 m depth, sand and nullipores, 8.VI.1934 [16 mm long, 2.5 mm wide; mature, gonads visible through body wall from chaetiger 10, as homogeneous masses; acicular lobe digitate, upper tine 5-7 times longer than rounded lower one] . — 1 specimen, LACM 8561 , RV Velero III, Sta. 304 (18°20’25”N, 114°44’30”W), 36 m depth, nullipores, algae, 11.VI.1934 [26 mm long, 3 mm wide; mature; body distorted, gonads exposed after body wall rupture; acicular lobe digitate, upper tine 4-5 times longer than rounded lower one; sperm spherical, about 5 µm in diameter]. Ecuador. 1 specimen, LACM 8583, RV Velero III, Sta. 213 (01°15’25”S, 81°05’15”W), off La Plata Island , 13-18 m depth, rock, nullipores, 10.II.1934 [14 mm long, 2 mm wide; macerated, body soft, semitransparent, including cirri; acicular lobe with upper tine very long, about 10 times longer than lower, rounded one] . — 1 specimen, LACM 10150, RV Velero III, Sta. 59 (01°14’31”S, 90°26’30”W), off Cormoranat Bay, Charles Island , Galápagos Islands, 23 m depth, 6.II.1933 [27 mm long, 4 mm wide; macerated; chaetal lobes invaginated, acicular lobe with upper tine 4-5 times longer than lower, rounded one]. — 1 specimen, LACM 148-34, RV Velero III, Sta. 148 (00°16’41”S, 91°22’39”W), Tagus Cove, Albermarle Island , Galápagos Islands, 22-45 m depth, 13.I.1934 [20 mm long, 2.8 mm wide; macerated, with abundant adsorbed particles on body and chaetae; chaetal lobes invaginated, acicular lobe with upper tine 4-5 times longer than lower, rounded one]. — 5 specimens, LACM 10151, RV Velero III, Sta. 167 (01°14’37”S, 90°28’08”W), Post Office Bay, Charles Island , Galápagos Islands, 27 m depth, rocks, 19.I.1934 [20-32 mm long, 2-4 mm wide; macerated, most cirri and neurochaetal blades on site; chaetal lobes variably invaginated; right parapodium of chaetiger 9 in 3 specimens removed (kept in vial); acicular lobe with upper tine 3-4 times longer than lower one; largest specimen mature; oocytes about 100 µm ]. — 1 specimen, LACM 10151, RV Velero III, Sta. 336 (00°16’30”S, 90°35’20”W), Sullivan Bay, James Island , Galápagos Islands, 36 m depth, 12.XII.1934 [25 mm long, 3 mm wide; macerated; pharynx fully everted; chaetal lobes slightly invaginated, acicular lobe with upper tine 4-5 times longer than lower, rounded one]. — 1 specimen, LACM 10161, RV Velero III, Sta. 811 (00°51’35”S, 90°02’00”W), Barrington Island , Galápagos Islands, shore, Pocillopora , 26.I.1938 [30 mm long, 4 mm wide; macerated; chaetal lobes invaginated; acicular lobe with upper tine tapered or digitate, 3-5 times longer than lower, rounded one].

DISTRIBUTION. — Eastern tropical Pacific , From Punta Eugenia, Baja California Sur, México to the Galápagos Islands, from intertidal to 45 m depth, in sandy or mixed bottoms.

DIAGNOSIS. — Hesione with prostomium slightly curved laterally; parapodia with dorsal cirri basally cylindrical, dorsal cirrophore twice as long as wide; larger acicula blackish; acicular lobe single, long, tapered, lower tine rounded, small; neurochaetal blades bidentate, 3-8 times as long as wide; subdistal tooth smaller than distal one, with guards approaching distal tooth.

DESCRIPTION

Holotype, USNM 19379, complete, tapered, colorless in ethanol, slightly macerated with several dorsal cirri and ventral cirri damaged or lost; chaetae from chaetiger 1 lost; body integument finely annulated dorsally, annulations not continued into lateral cushions, especially behind chaetal lobes ( Fig. 33A ). Body 39 mm long, 5 mm wide.

Prostomium as long as wide, anteriorly narrower, expanded towards posterior margin; anterior margin projected, posterior margin with a small furrow ( Fig. 33B ). Antennae minute, blunt, slightly as long as wide. Eyes barely pigmented, anterior ones placed by the middle of the prostomium, slightly larger and farther apart than posterior ones, displaced posteriorly.

Tentacular cirri damaged, longest ones reaching chaetiger 4. Lateral cushions projected, corrugated in anterior region, divided into two sections in posterior region.

Parapodia with dorsal cirri damaged; cirrophore annulated, about twice as long as wide; cirrostyle macerated, looking smooth. Ventral cirri with cirrophores small, indistinct; cirrostyle longer than chaetal lobe. Chaetal lobe thick, with parallel sides, slightly tapered, annulated basally ( Figs 33C , 34D, E ).

Neuraciculae blackish, two, one markedly thicker than the other. Acicular lobe single, tapered, rarely directed upwards, mostly projected laterally, sometimes with a round basal projection, upper tine (eroded) 3 times longer than lower one (basal tine not visible in other specimens, Fig. 34E ).

Neurochaetae about 16 neurochaetae per bundle, blades bidentate, slightly shorter ventrally, 8 times as long as wide, with a small subdistal tooth, guard usually passing it ( Fig. 33D ) (other specimens with blades 3-7 as long as wide, Fig. 34D ).

Pygidium with integument smooth; anus projected as a short, distally expanded cylinder ( Fig. 33E ); about 8 short, digitate anal papillae.

Pharynx not exposed. Oocytes not seen.

Pigmentation

Body with longitudinal, dorsal, irregular, discontinuous thin dark green or pale brown bands ( Fig. 34A ), restricted to first 2-3 anterior chaetigers, alternating with small, round spots, and completely replaced by them in medial and posterior chaetigers, expanded into lateral cushions, but not into pygidium.Tentacular and dorsal cirri colorless; cirrophores pale in anterior chaetigers, yellowish in posterior ones; chaetal lobes pale. Prostomium with thin irregular marginal lines. Longitudinal bands progressively thinner ( Fig. 34B ); all chaetigers with an irregular middorsal spot, irregularly ovoid, as long as wide, along chaetigers 1-6, becoming as long as wide in following chaetigers, connected by a thin, darker middorsal line continued to the last achaetous segment. This thin middorsal line bordered by paler areas, short in anterior and medial segments, becoming longer, running throughout all dorsal segmental surface in posterior segments. Pigmentation remaining visible after 8 years in ethanol ( Fig. 34C ).

REMARKS

Hesione panamena Chamberlin, 1919 , reinstated, resembles H. pantherina Risso, 1826 in the key below. Their main difference is the type of acicular lobe. In H. panamena acicular lobes are long, tapered, whereas in H. pantherina they can be short or long but their tips are blunt to distally swollen. Living specimens also differ because in H. panamena there are middorsal blackish, round spots whereas in H. pantherina there are middorsal pale areas.

Hesione panamena was originally spelled as such for the description ( Chamberlin 1919: 188) and H. panamica for the legends to figures, and although both epithets are correct, the former has been followed by subsequent authors. Chamberlin (1919: 189) indicated that antennae were broken off, but they are present in the type, although because their bases are not exposed, they are difficult to observe. The details of the neurochaetal blades, as indicated in the original illustrations (his plate 22, figures 9-10) are accurate by showing long blades, with a small subdistal tooth, and its guard usually passing subapical tooth.

Hesione panamena resembles H. intertexta Grube, 1878 by the small size of the eyes and antennae, and they also have similar neurochaetal blades. However, in H. panamena the blade length/width proportions are smaller and the antennae are ovoid, whereas in H. intertexta there is a wider variation in blade size, and antennae are tapered. Further, although pigmentation fades quite soon in ethanol, their patterns show some differences; in H. panamena , segmental longitudinal lines are discontinuous whereas they are continuous in H. intertexta , and in H. panamena , there is a blackish, as long as wide middorsal spot just before a paler area, and this is not so evident in H. intertexta . Further, in H. intertexta acicular lobe is single, without any lower one, whereas in H. panamena there can be a smaller, rounded lower tine.

Fauvel (1941: 9) recorded two Hesione species for the Gulf of California: H. pantherina Risso, 1826 (this record is herein regarded as belonging to H. panamena ), and H. genetta Grube, 1867 because of its pigmentation pattern: “à la face dorsale des traces de mouchetures brunes, ovales, alternées, qui rappellent la robe de la Genette.” (Transl.: on the dorsal surface there are remains of brown oval, alternating spots, resembling the genette skin). This specimen was found in the Paris museum, it differs from H. hartmanae n. sp. described above, and initially regarded as having potential affinities because acicular lobes are double in H. genetta and H. hartmanae n. sp., but the Paris specimen has acicular lobes single. Fauvel’s specimen had been in ethanol for about 50 years before he saw it, and he referred to a pigmentation pattern, but after other half a century spent before I studied the specimen, this pigmentation is now completely faded out. This specimen is also regarded as conspecific with H. panamena .

Monro (1926: 312) made a comparison of the size of guards and separated Hesione species into three groups; among those having guards approaching the apical tooth he listed H intertexta , H. reticulata von Marenzeller, 1879 , H. praetexta Ehlers, 1885 and H. panamena Chamberlin, 1919 . Further, in the previous page, Monro rejected, following Fauvel (1923a), the use of pigmentation pattern and the development of acicular lobes. As a consequence, in two of his publications on Panamian polychaetes ( Monro 1928: 79; 1933: 26) he regarded H. panamena as a junior synonym of H. intertexta , and recorded it for the Pacific coast of Panama. Hartman (1940: 212) followed this synonymy and listed specimens from Western Mexico to the Galápagos Islands, but her material includes two species: one with a very long upper acicular lobe, herein retained as H. panamena , and another one with two acicular lobes, which were illustrated, and were based on Galápagos specimens, which are regarded as belonging to an undescribed species and described above as H. hartmanae n. sp. The record of Hesione pantherina Risso, 1826 for the Gulf of California ( Fauvel 1941: 9) is regarded as belonging to H. panamena . Consequently, there are two species in the Galapagos ( Blake 1991: 78) but their names should be changed to H. panamena and H. hartmanae n. sp. (see above).

Figures

FIG. 33. — Hesione panamena Chamberlin, 1919, holotype, USNM 19379:A, anterior end, dorsal view; B, close-up of head (arrow points to right lateral antenna); C, chaetiger 8, right parapodium (inset: close-up of acicular lobe, upper tine eroded); D, same, blade of neurochaeta (inset: close-up of another neurochaetal blade tip); E, posterior region, dorsal view. Scale bars: A, 1.3 mm; B, 0.3 mm; C, 70 µm; D, 30 µm; E, 1.7 mm.

FIG. 34. — Hesione panamena Chamberlin, 1919, non-type specimens: A, dorsal view of living specimen, depressed by glass slide, ECOSUR OH 374, reddish hue due to blood vessels fracture after pressure and osmotic shock; B, same, anterior end, dorsal view; C, same, after some time in ethanol, pharynx barely ex- posed; D, chaetiger 6, right parapodium, anterior view (insets: blade tips); E, another specimen, LACM 8556, chaetiger 10, left parapodium, anterior view. Scale bars: A, 3 mm; B, 1 mm; C, 0.7 mm; D, 0.4 mm; E, 0.5 mm (photos: A, B, H. Bahenas).