Travisia brevis Moore, 1923

Tovar-Hernández, María Ana, Burgess, Dany E., León-González, Jesús Angel De & Hendrickx, Michel E., 2025, Travisiid worms from deep water off Western Mexico with the establishment of a new species (Annelida: Travisiidae), Zootaxa 5729 (2), pp. 349-369 : 351-355

publication ID	https://doi.org/10.11646/zootaxa.5729.2.7
publication LSID	lsid:zoobank.org:pub:259CD4C1-6727-4839-8074-38AF01A7E3B0
persistent identifier	https://treatment.plazi.org/id/038D8112-A02D-D67A-FBE0-FC78374226AF
treatment provided by	Plazi
scientific name	Travisia brevis Moore, 1923
status

Treatment

Travisia brevis Moore, 1923 View in CoL

( Figs 1‒3 View FIGURE 1 View FIGURE 2 View FIGURE 3 )

Travisia brevis Moore, 1923: 220‒221 View in CoL .— Berkeley & Berkeley, 1952: 90‒91, fig. 183.— Hartman, 1961: 34; 1966: 409; 1969: 343‒344, fig. 1.— Imajima, 1963: 361; 1964: 247; 2009: 138–139 — Reish, 1965: 145.— Fauchald, 1972: 237.— Hobson & Banse, 1981: 62, fig. 13h.— Blake, 2000: 161‒162, fig. 7.7.— Hendrickx, 2005: 83.— Méndez, 2006: 777; 2007: 609; 2012: 184.— Mercado-Santiago et al. 2021: 388.— Hernández-Alcántara et al. 2023: 4.— Hernández-Alcántara et al. 2025: 6.

Material examined. All off Guerrero, Mexico. ICML-EMU-14077-A, TALUD XI, St. 2, BC, 16º47’42”N, 100º28’12”W, 07 June 2007, 880 m, 1 specimen GoogleMaps . ICML-EMU-14077-B, TALUD XI, St. 5, BC, 16º52’35”N, 100º47’34”W, 07 June 2007, 1550 m, 1 specimen GoogleMaps . ICML-EMU-14078-A, TALUD XII, St. 8, BC, 17º04’16”N, 101º39’28”W, 29 March 2008, 1928 m, 3 specimens GoogleMaps . ICML-EMU-14078-B, TALUD XII, St. 27, BS, 18º40’28”N, 104º35’51”W, 02 April 2008, 1040‒1095 m, 3 specimens GoogleMaps .

Diagnosis. Travisia with annulate branchiae from chaetiger 2, 18‒21 pairs of branchia and 19‒22 chaetigers. Mid-ventral groove absent. Nuchal organs small, C-shaped. Parapodial lappets well-developed, present along body.

Description. Specimens 20‒23 mm long, 3.5‒6.0 mm wide with 19‒22 chaetigers. Body brownish in alcohol; robust, grub-like ( Fig. 1A‒B View FIGURE 1 ) with rugose epidermis ( Figs 1‒3 View FIGURE 1 View FIGURE 2 View FIGURE 3 ). Mid-ventral groove absent.

Prostomium small, conical, pointed, smooth, iridescent ( Figs 1A, C‒E View FIGURE 1 , 2A View FIGURE 2 , 3A‒B View FIGURE 3 ). Nuchal organs small, Cshaped, dorsolateral ( Figs 1C‒D View FIGURE 1 , 3A‒B View FIGURE 3 ). Eyes absent. Mouth between chaetigers 1 and 2 ( Figs 1E View FIGURE 1 , 3B View FIGURE 3 ). Pharynx not everted in any specimens.

Peristomium uniannulated. Chaetiger 1 biannulated. Chaetigers 2 to 19 triannulated. Following chaetigers uniannulated to pygidium. Segments from first two body quarters with annulation visible along entire segment width (from parapodium to parapodium); segments from third body quarter toward posterior end with annulation visible only on middorsal and midventral zones (annulation not reaching parapodia).

Epithelium of peristomium and first three chaetigers fully covered with small, spherical papillae (dorsal, ventral and laterally) ( Figs 1A, C‒E View FIGURE 1 , 2A View FIGURE 2 , 3A‒B View FIGURE 3 ). In chaetigers 4 to 13, dorsal and ventral surfaces with three narrow ridges, each ridge with 1‒2 rows of tightly packed, small, spherical papillae with lateral-most papillae enlarged ( Figs 1A View FIGURE 1 , 2B, E View FIGURE 2 ); lateral sides with epithelium fully covered with small, rounded papillae ( Fig. 2B‒C View FIGURE 2 ). Mid-body segments with five broad ridges dorsally and ventrally, each composed of many tight papillae, unequal in size ( Fig. 2F View FIGURE 2 ). An intersegmental package of papillae ventrally along last body quarter, oval-shaped to rim-shaped, depending on fixation ( Fig. 3C‒D View FIGURE 3 ); papillae diminishing gradually in size toward posterior segments.

Interamal sensory pores small, present between notochaetae and neurochaetae from chaetiger 2 to near last segments ( Figs 1B View FIGURE 1 , 2C View FIGURE 2 ). Lateral nephridial pores not seen.

Branchiae annulate ( Fig. 2A‒D View FIGURE 2 ), 18‒21 pairs, starting in chaetiger 2. First pair short, increasing in size towards medium chaetigers, decreasing in size gradually to posterior end ( Figs 1A‒B View FIGURE 1 , 2A‒D View FIGURE 2 ). Last branchia small, digitate.

Parapodial lappets conical, present from chaetiger 17 continued to posterior segments, covered by clusters of dense, small spherical papillae ( Fig. 2G‒I View FIGURE 2 ). From chaetiger 20 to end, distal-most papilla of parapodial lappets remarkably larger than basal ones ( Fig. 2G‒I View FIGURE 2 ).

Parapodia biramous. All noto- and neurochaetae iridescent, spinulose capillaries. Last 4‒6 segments achaetous.

Pygidium short, thick, with one ring of 12 lobes, without anal cirri ( Figs 1B View FIGURE 1 , 2D View FIGURE 2 , 3C‒E View FIGURE 3 ).

Methyl green staining. Prostomium and branchiae unstained ( Fig. 3A, C View FIGURE 3 ). Rest of the body is uniformly stained.

Remarks. Travisia brevis has been reported in many ecological surveys and technical reports (e.g., Méndez 2006, 2007, 2012; Carson & Hentschel 2006; Henkel et al. 2020; Mercado-Santiago et al. 2021), but apart from the original description there are few illustrations of this species. Unfortunately, the original establishment by Moore (1923) did not include drawings. Berkeley & Berkeley (1952: fig. 183) included a drawing of the body in dorsal view which was later replicated by Hartman (1969: fig. 1) and Blake (2000: fig. 7.7A). A chaetiger in lateral view was illustrated by Hobson & Banse (1981: fig. 13h) and then replicated by Blake (2000: fig. 7.7B). Digital photographs of T. brevis are available in technical sheets of the Southern California Association of Marine Invertebrate Taxonomists ( SCAMIT 2016) and Burgess (2018a). In the present study, a full description and additional digital photographs of body structures are provided (see Figs 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 ) in order to help further identifications of T. brevis in western Mexico or elsewhere along the eastern Pacific.

Species of Travisia have been classified in two groups based on the absence or presence of branchiae by Rizzo & Salazar-Vallejo (2020, 2021 taxonomic identification key) and Plathong et al. (2023). Group I includes four species lacking branchiae whereas group II consists of species with branchiae. Group II is also separated into two subgroups based on the type of branchiae: subgroup A with branched branchiae, and subgroup B with cirriform branchiae. Subgroup B is further divided into B1 based on the presence of a ventral groove, and B2 lacking a ventral groove. Following this recognition of groups and subgroups, B2 is currently composed of 33 species when the three species described by Avery et al. (2023) are considered.

A comprehensive comparison of species of Travisia is a complicated matter, mostly because after their establishment they have seldom been recorded and are often included in lists of species or ecological studies without being thoroughly examined from a morphological point of view. Revisions based on type material, redescriptions, and appropriate illustrations are not available. The majority of the original descriptions do not include adequate description of the morphological features that the current study of Travisia demands (see Rizzo & Salazar 2020, Yang et al. 2022, Avery et al. 2023, Plathong et al. 2023). Some do not even include figures of body structures or, if present, these can be interpreted erroneously or in a speculative manner. In addition, the size of worms, number of chaetigers, achaetous segments and branchia, and the beginning of interamal sensory pores and lateral nephridiopores may be features with discrete or overlapped variations that do not allow a precise distinction of taxa to species level. Besides, intrasegmental divisions and patterns of papillation are features that demand a very detailed and specific study, sometimes difficult to perform due to body contractions or to a dense papillation above the body epithelium.

Abiotic conditions. The specimens of T. brevis were collected from 880–1928 m depth, under the following environmental conditions: temperature, 2.3–5.1°C; salinity, 34.53–34.63 ppm; dissolved oxygen, 0.24– 1.49 O 2 mg / L; %CO, 1.37–1.96; sediments composition variable, including silty clay, mixed, and muddy sand ( Table 1).