Notomastus mazatlanensis, García-Garza & León-González & Tovar-Hernández, 2019

García-Garza, María Elena, León-González, Jesús Angel De & Tovar-Hernández, María Ana, 2019, Catalogue of Notomastus M. Sars, 1851 (Annelida, Capitellidae) and the description of a new species from the Gulf of California, Zootaxa 4577 (2), pp. 249-273 : 262-263

publication ID	https://doi.org/ 10.11646/zootaxa.4577.2.2
publication LSID	lsid:zoobank.org:pub:C61988A5-561D-4E34-9C0B-2E8BFF23BF25
DOI	https://doi.org/10.5281/zenodo.5940531
persistent identifier	https://treatment.plazi.org/id/038BC67D-3A5E-FFE5-FF5A-A74BFC33F8D9
treatment provided by	Plazi
scientific name	Notomastus mazatlanensis
status	sp. nov.

Treatment

43. Notomastus mazatlanensis View in CoL sp. nov.

( Fig. 6 View FIGURE 6 a–e)

Material examined. Holotype (UANL-8128) Eastern Pacific, Mexico, Southern Gulf of California, Sinaloa, Mazatlán , Marina Mazatlán , 23°16’2.1”N, 106°27’14.5”W, September 5, 2018, 6 m, mud. (4) GoogleMaps Paratypes (UANL- 8129), October 11, 2015, Colls. MEG-G, MAT-H and JAL-G. Comparative material examined. Notomastus hemipodus Hartman, 1945 : Holotype ( LACM-AHF Poly 414) , Paratypes (4) ( LACM-AHF Poly 415), (1) ( LACM- AHF Poly 2667), (2) ( LACM-AHF Poly 2668); (6) ( LACM-AHF Poly 2669). Notomastus fauvelii Day, 1955 : Holotype ( BMNH 1961.16.73-74) .

Diagnosis. Prostomium conical with palpode and eyespots. Thorax with an achaetous peristomium and 11 chaetigers with capillary chaetae. First chaetiger uniramous. Abdominal segments with hooded hooks in both rami. Branchiae present dorsally. Pygidium without appendages.

Description. Holotype incomplete, fragmented in 4 parts, anterior fragment with 50 segments, 22.2 mm long, 0.89 mm wide, and 38 segments, 14.8 mm long, 0.86 mm wide; posterior fragments with 43 segments, 15.5 mm long, 1.2 mm wide, and 68 segments, 38.0 mm long, 1.4 mm wide. Paratypes incomplete, 50–89 segments, 22–66 mm long, 1.4 mm wide. Color in ethanol reddish-white. Prostomium conical with palpode. Eyespots covered by peristomium, small, forming discrete groups on both sides of prostomium. Proboscis everted, globular, finely papillated. Peristomium and chaetigers 1-3 with tessellated epithelium; following thoracic segments smooth ( Fig. 6a View FIGURE 6 ).

Thorax with 11 chaetigers armed with bi-limbated capillary chaetae. First chaetiger uniramous. Thoracic chaetigers biannulated. Notopodia inserted laterally in first fifth thoracic chaetigers, then notopodia inserted dorsally from chaetiger 6 to posterior thorax ( Fig. 6a View FIGURE 6 ). Lateral organs occurring from first thoracic chaetiger ( Fig. 6a View FIGURE 6 ) towards abdominal segments, between noto- and neuropodia, but closer to notopodia; abdominal lateral organs as small protuberances, closer to notopodial lobes ( Fig. 6b View FIGURE 6 ). Genital pores located at chaetigers 8–11, under neuropodial lobes.

Transition between thorax and abdomen marked abruptly by size of segments. Abdominal segments with smooth epithelium. Abdominal neuropodia with hooded hooks throughout. Abdominal notopodia widely separated dorsally, without lobe, with hooded hooks on both rami (six hooks per fascicle) ( Fig. 6b View FIGURE 6 ). Neuropodial lobes ventrally separated, with 28–30 hooded hooks per fascicle ( Fig. 6e View FIGURE 6 ). Digitiform, eversible branchia emerging from body wall on medial abdominal segments and so on towards posterior end; branchiae aligned below the notopodia bearing 3–4 branchial filaments initially ( Fig. 6c View FIGURE 6 ) and 28–30 in posterior segments ( Fig. 6d View FIGURE 6 ). Hooded hooks similar in shape on noto- and neuropodia; long anterior shaft, angulated node, evident constriction, posterior shaft longer than anterior one, developed shoulder, covered with numerous apical filaments; with a main fang and four rows of small teeth, basal row with three teeth, intermediary row with 4–5 teeth and distal, one with an indeterminate number ( Fig. 6f View FIGURE 6 ). Pygidium without appendages.

Methyl green staining pattern. Prostomium, peristomium and chaetigers 1 and 2 stained light green; chaetigers 3 and 4 with moderate green, and chaetigers 5–11 dark green ( Fig. 6a View FIGURE 6 ). Anterior abdominal segments stained dark green dorsally ( Fig. 6b View FIGURE 6 ). Posterior abdominal segments stained dark green, with a dotted band around each segment ( Fig. 6c, e View FIGURE 6 ).

Remarks. Notomastus mazatlanensis sp. nov., is similar to N. fauvelii and N. hemipodus by having finger-like branchiae emerging from the epithelium near the notopodia. However, N. mazatlanensis sp. nov. differs from N. fauvelii by presenting the first chaetiger uniramous and the digitiform branchiae grouped in 3–4 filaments in anterior abdominal segments, while N. fauvelii has the first chaetiger biramous ( Fig. 4a View FIGURE 4 ) and the branchiae are composed by 15 filaments in anterior abdominal segments ( Fig. 6h View FIGURE 6 ). Furthermore, glandular staining pattern is markedly different in N. fauvelii : peristomium, segments 6–9 and post-chaetal area of segment 11 stain moderate green; abdominal segments have two pre and post-chaetal longitudinal bands dark green running along, and each abdominal segment present narrow, transversal bands dark green ( Fig. 4a View FIGURE 4 ).

Notomastus mazatlanensis sp. nov. and N. hemipodus present the first chaetiger uniramous, but both species differ in that N. mazatlanensis sp. nov. has 3–4 branchial filaments per notopodium, while N. hemipodus presents bilobed branchiae ( Fig. 6g View FIGURE 6 ). In addition, the glandular staining pattern of N. hemipodus is very evident in the abdominal segments, presenting moderate green marks, and ventral region with a pair of longitudinal bands toward the end of the body.

Etymology. The specific name is related to the type locality where the new species was found: Mazatlán, in a marina located in the Southern Gulf of California, México ( Fig. 1 View FIGURE 1 ).