Notorhinus, Moritz & Parra-Gómez, 2023

Moritz, Leif & Parra-Gomez, Antonio, 2023, Notorhinus floresi sp. nov. gen. nov.: The first records of Siphonophorida in Chile and Siphonorhinidae in South America (Colobognatha), Arthropod Systematics & amp; Phylogeny 81, pp. 565-579 : 565

3.1.2. Genus Notorhinus gen. nov.

Type species.

Notorhinus floresi sp. nov.

Diagnosis.

Pale, thin and elongated Siphonorhinidae with pyriform heads. In Notorhinus gen. nov. (Figs 2 , 7 ) two backwards projecting spines are situated behind the elevated ozopores (Figs 4E , 8G ), and the posterior margin of the metazonite (limbus) carries sculptures in shape of a fluke (tail-fin) (Figs 4D , 8H ). Notorhinus gen. nov. differs from all other Siphonorhinidae genera by the absence of sensilla basiconica on antennomere 5 and the arrangement of numerous sensilla basiconica on antennomere 6 in a field not sunken into a sensory pit (Figs 3E , 8C ). In Siphonorhinus and Kleruchus (see Attems 1930 for S. pellita ; Attems 1938 for Teratognathus (syn. of Siphonorhinus ) and Kleruchus ) numerous sensilla basiconica are located in sensory pits (Sinnesgruben sensu Attems 1930) on antennomeres 5 and 6. In Illacme few sensilla basiconica are arranged in rows along the apical margin of antennomeres 5 and 6 ( Marek et al. 2012, 2016) and in Madagascarhinus sensilla basiconica are arranged in 2 - 3 rows on antennomeres 5 and 6 ( Wesener 2023). In Nematozonium no sensory structures are evident on the antennae according to Shelley and Hoffman (2004). Notorhinus gen. nov. differs from Illacme by the fusion of the first legs’ coxae to the sternite (Fig. 3G ), forming a coxosternite (see Marek et al. 2012, 2016 for Illacme ), as is the case in Siphonorhinus (see Enghoff et al. 2015). Furthermore, the specimens differ from Kleruchus by the presence of an anal scale/hypoproct (Figs 4F , 8I ) (Analschuppe sensu Attems 1938).

Remarks.

Several characters are shared with the genus Illacme Cook and Loomis, 1928 (see Marek et al. 2012, 2016 for detailed documentation): antennomeres 5 and 6 longer and wider; antennae elbowed between antennomeres 3 and 4 (Fig. 3B ); presence of cluster of spiniform sensilla basiconica (spiniform basiconic sensilla sensu Marek et al. 2016) next to apical sensory cones (Fig. 3F ); labrum with incision, lined by teeths; pores of salivary glands arranged in a single circular field above the labrum (Fig. 3C ); gonopods with 7 podomeres (Fig. 5E ); posterior gonopods apical podomere with three branches: two apically laminate/flattened branches and a single posterior spine-like branch (Fig. 5F ). However, some of these characters are not well studied in the remaining genera of the Siphonorhinidae .

Etymology.

Noto is derived from the ancient greek νότος ( nótos) meaning south and refers to the distribution of the genus in South America and the fact that it is the most southern record of the family Siphonorhinidae . Rhinus is derived from the ancient Greek ῥῑ ́ς (rhī́s; genitive: ῥῑνός ( rhīnós)), meaning nose, and refers to the acuminate head shape. Rhinus is often part of taxonomic names in the group (e.g. Siphonorhinidae Cook, 1895, Siphonorhinus Pocock, 1894, Madagascarhinus Wese-ner, 2023).

Figures

Figure 2. Notorhinus floresi sp. nov., photographs. A, B Living specimen in its natural habitat. Photographs by Edgardo Flores. C Male paratype (ZFMK-MYR 12267), habitus, lateral view. D Female paratype (ZFMK-MYR 12269), head, lateral view.

Figure 3. Notorhinus floresi sp. nov., male holotype (MNHNC 8387), head, SEM. A Head, frontal view. B Head, lateral view. C Labrum, frontal view. D Labrum and gnathochilarium, ventral view. E Apical antennomeres, lateral view. F Apical antennomere, apical view. G Gnathochilarium and leg-pair 1, ventral view. Abbreviations: I-VII = antennomeres, ac = apical cones, cl = claw, co = collum, cx = coxa, ep = epicranium, fe = femur, fh = forehead, ge = genae, in = inscision of the labrum, la = labrum, LL = lamella lingualis, lp = spinous protuberences of labrum, lt = teeth lining labral incision, me = mentum, pa = palp-like structure, po = pores of the salivary glands, pof = postfemur, prf = prefemur, sb = sensilla basiconica, ssb = spiniform sensilla basiconica, sti = gnathochilarial stipes, ta = tarsus, ti = tibia.

Figure 4. Notorhinus floresi sp. nov., male holotype (MNHNC 8387), body-rings and legs, SEM. A Mid-body-rings, dorsal view. B Mid-body-rings, lateral view. C Mid-body-rings, ventral view, legs removed. D Metazonite posterior margin (limbus), arrow indicates fluke-shaped sculpture. E Ozopore, lateral view, arrows indicate spines behind ozopore. F Telson, posterior view. G Mid-body leg, anterior view. H Leg 2, tarsal claw, arrow indicates division of tarsal claw. Abbreviations: cl = claw, cs = coxal sac, cx = coxa, fe = femur, hp = hypoproct (subanal scale), mz = metazonite, oz = ozopore, pl = pleurite, pof = postfemur, pp = paraproct (anal valve), pr = preanal ring, prf = prefemur, pz = prozonite, sp = spiracle, st = sternite, ta = tarsus, ti = tibia, tr = trochanter.

Figure 5. Notorhinus floresi sp. nov., male holotype (MNHNC 8387), sexual characters, SEM. A Leg 2, ventral view. B Male pseudopenis bearing the gonopore, ventral view. C Male pseudopenis bearing the gonopore, posterior view. D Anterior and posterior gonopods, ventral view. E Anterior and posterior gonopods, ventro-lateral view. F Right anterior and posterior gonopod, detail of the apical podomeres. Abbreviations: a 1 - a 7 = podomeres of the anterior gonopod, cx = coxa, f 1 = pointed / spinous branch of the posterior gonopod's apical podomere, f 2 and f 3 = laminate branches of the posterior gonopod's apical podomere, go = pseudopenis carrying the gonopore, p 1 - p 7 = podomeres of the posterior gonopod, st = sternite associated with anterior gonopods.

Figure 7. Notorhinus sp., female (MNHNC 8390). A Habitus, lateral view. B Head and anterior body, lateral view.

Figure 8. Notorhinus sp., female (MNHNC 8390), SEM. A Head and anterior body-rings, frontal view. B Apical parts of gnathochilarium and labrum, ventral view. C Left antenna, lateral view. D Antennomere 7 with apical sensory structures. E Tarsal claw of mid-body leg. F Mid-body tergite, dorsal view. G Ozopore, lateral view, arrows indicate spines behind ozopore. H Posterior tergal margin (limbus), dorsal view, arrow indicates fluke-shaped sculpture. I Posterior body-rings and telson, ventral view. Abbreviations: I-VII = antennomeres, ac = apical cone, cl = tarsal claw, co = collum, ep = epicranium, fh = forehead, gn = gnathochilarium, hp = hypoproct, L 1 = leg-pair 1, L 2 = leg-pair 2, la = labrum, LL = lamella lingualis, md = mandible gnathal lobe, me = mentum, mz = metazonite, oz = ozopore, pp = paraproct, pr = preanal ring, pz = prozonite, sb = sensilla basiconica, ssb = spiniform sensilla basiconica, sti = gnathochilarial stipes, ta = tarsus.