Leptonereis nota Treadwell 1941: 1–3
de Jesús-Flores et al. 2016: 209–213
Laeonereis culveri Pettibone 1971: 15
Revision of Laeonereis Hartman, 1945 (Annelida: Phyllodocida: Gymnonereidinae), with a review of shaft morphology in nereidids
Conde-Vela, Víctor M.
Journal of Natural History
2021
2021-06-11
55
7 - 8
381
455
8M34S
(Treadwell, 1941)
Treadwell
1941
[455,861,748,774]
Polychaeta
Nereididae
Laeonereis
Animalia
Phyllodocida
38
419
Annelida
species
nota
( Figures 6, 17(a–e), 18(a–d), 19(a–l), and 20(a–h)
Leptonereis nota Treadwell 1941: 1–3, figs 7–10. de Jesús-Flores et al. 2016: 209–213, figs 2A–F, 3A–D, 4A–F. Laeonereis culveri Pettibone 1971: 15, fig. 5c, d ( partim, non Webster, 1879).
Type locality Offats Bayou, Galveston, Texas, Gulf of Mexico. Type material Gulf of Mexico, Atlantic Ocean. Holotypeof Leptonereis notaAMNH 2896, Offats Bayou, Galveston, Texas, no date, Coll. W.G. Hewatt. Additional material USNM 1490824 (3), Wiggam’s Pass, Naples, Florida, Inlet Beachside, 28 December 1958, Coll . C. Long . USNM 1490825 (10), Rock Creek, Naples, Florida, 24 December 1959, Coll . C. Long.
Description Holotype( AMNH 2896) incomplete, 50 mmlong, 1 mmwide at chaetiger 10, 83 chaetigers, specimen previously dissected, several parapodia previously removed, pharynx everted ( Figure 17(a–e)). Non-type specimens ( USNM 1490825) used for complete description, 52 mmlong, 2 mmwide at chaetiger 10, 117 chaetigers ( Figure 18(a–c)); one specimen( USNM 149824) found inside a tube made with sand in a soft matrix ( Figure 18(d)). Specimens brownish, body pigmentation faded out in holotype; anterior chaetigers in non-type specimen with a dorsal, transverse light brown line, almost faded out; glandular masses in parapodia and dorsal side of chaetigers visible in holotype( Figure 17(a,c)). Figure 17. Laeonereis nota( Treadwell, 1941). (a–e), holotype AMNH 2896. (a) anterior end, dorsal view; (b) anterior end, lateral view; (c) posterior end, dorsal view; (d) whole specimen, dorsal view; (e) anterior end, ventral view. Scale bars: a–c, e = 0.5 mm; d = 2.4 mm. Prostomium hexagonal, wider than long, anterior margin shallowly cleft, dorsal groove wide and reaching anterior pair of eyes ( Figure 17(a)); antennae digitiform, as long as dorsal groove ( Figure 17a); eyes black, elliptical to reniform, the two pairs subequal Figure 17(a)). Achaetous ring 1.5–2.0 times longer than first chaetiger ( Figures 17(a), 18(b)); four pairs of anterior cirri, cirrophores inconspicuous, longest pair of cirri reaching chaetiger 1 ( Figures 17(a,b), 18(a,b)). Figure 18. Laeonereis nota( Treadwell, 1941). (a–c), non-type USNM 1490825; (d), non-type USNM 1490824. (a) whole specimen, dorsal view; (b) anterior end, dorsal view; (c) posterior end, dorsal view; (d) tube with specimen partially exposed. Scale bars: a = 2 mm; b, d = 1 mm; c = 0.5 mm. Pharynx everted in holotype( Figure 17(b,e)). Maxillary ring: I = 1–1 tuft of verticillate rod-like papillae; II = 1–1 tuft of verticillate rod-like papillae; III = 3 tufts of verticillate rodlike papillae; IV = 1–1 tuft of verticillate rod-like papillae ( Figure 17(b,e)). Oral ring: V = 0, VI = 1–1 triangular papilla; VII–VIII = one ridge row with 5 rounded papillae, 1 papilla on each A–C region ( Figure 17(b,e)). Pattern of pedal glands ( Figure 6). UpG cordiform and as wide as MeG, becoming L-shaped in middle chaetigers. LoG triangular or elliptical and shorter than UpG in anterior chaetigers, becoming shorter in middle chaetigers. MeG rounded and 3 times larger than PoG, subequal in middle chaetigers. PoG becoming larger towards middle chaetigers. First two chaetigers with neuroaciculae only; remaining ones with both noto- and neuroaciculae. In first two chaetigers ( Figure 19(e)), dorsal cirri linguiform. Dorsal ligules subconical, blunt, 1.2 times longer than wide, 2.8 times longer than dorsal cirri, as long as neuropodial postchaetal lobes. Neuroacicular ligules subconical, distally bilobed, twice as wide as long; postchaetal lobes digitiform, as long as wide, twice as long as neuroacicular ligules, 1.2 times longer than neuropodial ventral ligules; neuropodial ventral ligules digitiform, 1.7 times wider than long, 1.7 times longer than ventral cirri. Ventral cirri subconical. In anterior chaetigers ( Figure 19(a,f)), dorsal cirri linguiform. Notopodial dorsal ligules subconical, blunt, 2.3 times wider than long, 3 times longer than dorsal cirri, twice as long as prechaetal lobes; prechaetal lobes digitiform, 1.5 times longer than wide; notopodial ventral ligules digitiform, 1.3 times longer than wide, twice as long as prechaetal lobes, 1.5 times longer than neuropodial postchaetal lobes. Neuroacicular ligules subconical, distally bilobed, as long as neuropodial ventral ligules; postchaetal lobes digitiform, 1.2 times longer than wide, 1.4 times longer than neuroacicular ligules, twice as long as neuropodial ventral ligules; neuropodial ventral ligules digitiform, 3 times wider than long, 2.3 times longer than ventral cirri. Ventral cirri subconical. Figure 19. Laeonereis nota( Treadwell, 1941). (a–d), holotype AMNH 2896; (e–l), non-type USNM 1490825. (a) chaetiger 8, right parapodium; (b) chaetiger 20, right parapodium; (c) chaetiger 39, right parapodium (NaL with distorted shape); (d) chaetiger 77, left parapodium; (e) chaetiger 2, right parapodium; (f) chaetiger 10, right parapodium; (g) chaetiger 25, right parapodium; (h) chaetiger 40, left parapodium; (i) chaetiger 60, left parapodium; (j) chaetiger 80, right parapodium; (k) chaetiger 97, right parapodium; (l) chaetiger 112, right parapodium. Scale bars: 0.1 mm. Figure 20. Laeonereis nota( Treadwell, 1941). (a–h) non-type USNM 1490825. (a) notopodial homogomph spiniger, chaetiger 25; (b) supra-acicular homogomph spiniger, chaetiger 10; (c) supra-acicular homogomph spiniger, chaetiger 25; (d) supra-acicular homogomph spiniger, chaetiger 40; (e) subacicular homogomph spiniger, chaetiger 10; (f) sub-acicular homogomph falciger, chaetiger 25; (g) sub-acicular homogomph falciger, chaetiger 60; (h) sub-acicular homogomph falciger, chaetiger 80. Scale bars: 10 µm. In middle chaetigers ( Figure 19(b,c,g,h)), dorsal cirri linguiform. Notopodial dorsal ligules digitiform, 1.4–1.6 times wider than long, 4.5 times longer than dorsal cirri, 2.5 times longer than prechaetal lobes; prechaetal lobes digitiform, as long as wide, disappearing quickly towards posterior chaetigers; notopodial ventral ligules subconical, blunt, 1.3 times longer than wide, 1.2–1.5 times longer than notopodial dorsal ligules. Neuroacicular ligules subconical, 1.2 times longer than notopodial ventral ligules, 2.5 times longer than neuropodial ventral ligules; postchaetal lobes absent; neuropodial ventral ligules digitiform, 4.5 times wider than long, 2.6 times longer than ventral cirri. Ventral cirri subconical. In posterior chaetigers ( Figure 19(d,i,j)), dorsal cirri linguiform. Notopodial dorsal ligules digitiform to subconical, 1.6 times wider than long, 3.2 times longer than dorsal cirri; prechaetal lobes absent; notopodial ventral ligules subconical, 1.5 times longer than notopodial dorsal ligules, twice as long as wide, 1.0–1.5 times longer than neuroacicular ligules. Neuroacicular ligules subconical, 1.3 times longer than wide, 3–5 times longer than neuropodial ventral ligules; postchaetal lobes absent; neuropodial ventral ligules digitiform, 4.2 times wider than long, 10–11 times longer than ventral cirri. Ventra cirri subconical. In posteriormost chaetigers ( Figure 19(k,l)), dorsal cirri linguiform. Notopodial dorsal ligules subconical, as long as wide, 3 times longer than dorsal cirri, half as long as notopodial ventral ligules, becoming shorter in posteriormost chaetigers; notopodial ventral ligules subconical, 1.7–2.0 times longer than wide, as long as neuroacicular ligules. Neuroacicular ligules subconical, 1.0–1.3 times wider than long, 3 times longer than neuropodial ventral ligules; postchaetal lobes absent; neuropodial ventral ligules subconical, 3.7–4.7 times wider than long, 6 times longer than ventral cirri. Ventral cirri subconical. Notopodia homogomph spinigers. Neuropodia homogomph spinigers in supraacicular fascicles, homogomph spinigers and falcigers in sub-acicular fascicles; subacicular homogomph falcigers absent in anterior chaetigers. Notopodial and neuropodial homogomph spinigers pectinate, minute teeth, decreasing in size towards distal end ( Figure 20(a–d)); sub-acicular spinigers with teeth slightly longer than notopodial and supra-acicular ones ( Figure 20(a–d)). Neuropodial homogomph falcigers pectinate, minute teeth, distal tooth stout and hook-like ( Figure 20(f–h)), appearing from chaetigers 15–20; blades 11–12 times longer than wide in anterior chaetigers, becoming 18 times longer than wide towards posterior chaetigers ( Figure 20(g,h)); blades slightly increasing in size due to blades increasing their length from upper to lower positions in the same fascicle. Pygidium funnel-shaped; anal cirri cirriform, 2–3 times longer than width of pygidium ( Figure 18(c)).
Remarks The original description by Treadwell (1941)agrees well with the current description, with the following differences: (1) the original description stated the longest pair of anterior cirri reaches chaetiger 3 (‘fourth somite’), whereas in the specimens examined here they reach the end of chaetiger 1; the original description noted the presence of neuropodial postchaetal lobes in posterior chaetigers, but in the specimens examined they are absent in these chaetigers. Treadwell (1941)placed this species in the genus Leptonereisbecause of the lack of paragnaths in the pharynx, but he overlooked the presence of papillae, as Pettibone (1971)highlighted later. Hartman (1951)regarded Leptonereis notaas a synonym of Laeonereis culveri, but no comments about this were made; illustrations in Hartman’s (1951)work correspond to the species L. longula sp. nov., probably based on specimens from Lemon Bay, Sarasota, Florida. Pettibone (1971)followed this decision without further argumentation. After this, de Jesús-Flores et al. (2016)examined topotype and additional specimens of both L. culveriand L. notaand rejected this synonymy, arguing differences in parapodial morphology are taxonomically significant; these differences are discussed in the Remarks section of L. acutaabove. The examination of specimens from Chetumal Bay demonstrated that specimens are very similar to those from the Gulf of Mexico, especially in body measurements such as body size and the number of chaetigers, and in parapodial and chaetal morphology, as found in a previous work ( de Jesús-Flores et al. 2016); de Jesús-Flores et al. (2016)proposed dispersion via migratory birds. Finally, the same authors suggested that pigmentation in the holotypeis a preservation artefact that likely could be removed by brushing the specimen ( de Jesús-Flores et al. 2016); however, the dark pigmentation of the body and glands is not an artefact, and additional specimens have a similar body colouration. Laeonereis notadiffers from L. culveriin the following features: in anterior chaetigers of L. nota, notopodial dorsal ligules are subconical and 3 times longer than dorsal cirri, whereas in L. culverithey are lanceolate and 6–7 times longer than dorsal cirri; in middle chaetigers of L. nota, notopodial ventral ligules are longer than notopodial dorsal ligules, whereas in L. culverithey are shorter; in middle and posterior chaetigers of L. nota, the notopodial dorsal ligules are 3.2–4.5 times longer than dorsal cirri and the notopodial ventral ligules are subequal to neuroacicular ones, whereas in L. culverithe notopodial dorsal ligules are 5–8 times longer than dorsal cirri and notopodial ventral ligules are longer than neuroacicular ones. Laeonereis notais also similar to L. pandoensis, but some differences can be noted: in anterior chaetigers of L. nota, the notopodial dorsal ligules are 3 times longer than the dorsal cirri, whereas in L. pandoensisthey are 4 times longer; in middle and posterior chaetigers of L. nota, the notopodial ventral and neuroacicular ligules are subequal, whereas in L. pandoensisthe notopodial ventral ligules are 1.5 times longer than neuroacicular ones; in L. nota, the blades of the neuropodial homogomph falcigers become wider towards the distal end, whereas in L. pandoensisthey become narrower.
Offats Bayou & Galveston & Coll. W. G. Hewatt.
Mexico
38
419
1
Mexico
holotype
1958-12-28
Wiggam's Pass
Inlet Beach
Naples
38
419
1
Florida
[205,235,1287,1312]
1958-12-28
Wiggam's Pass
true
Inlet Beach
Naples
38
419
1
Florida
[306,1152,1287,1312]
1959-12-24
Naples
Rock Creek
38
419
1
Florida
1959-12-24
true
Naples
Rock Creek
38
419
1
Florida
AMNH
38
419
AMNH 2896
1
holotype
USNM
38
419
USNM 1490825, USNM 149824
1