(FZB.Pyc–001) 31 specimens, Fernando de Noronha, Pernambuco, Brazil, Dec 21, 1978; (FZB.Pyc–007) 5 specimens, Perequê, Nov 2, 1972.

Brazil: São Paulo and Paraíba (Lucena and Christoffersen 2018a; Lucena et al. 2019a). Seychelles (Aldabra Atoll), Mauritius, Oman and Tonga (Child 1998a; Bamber 2004).

Shallow waters.

The species is recorded herein for the first time for the Archipelago of Fernando de Noronha, expanding its known distribution in north-eastern Brazil. All 31 specimens obtained from Fernando de Noronha were found associated with the epibiont hydrozoan Clytia? Lamouroux, 1812 (FZB.Pyc–001).

The hydrozoans occurred on both the dorsal and ventral surfaces of the trunk (mainly near the dorsal tubercles and the lateral processes), on eggs and ovigers and more densely on the legs (Fig. 2). Besides occurring on the proximal articles, as observed by Pipe (1982), we also found them mainly on the distal articles, such as the tibia 2 and even on the propodus. Visual differences in epibiont density were not noted amongst ovigerous and non-ovigerous individuals.

Figure 2. 

Ascorhynchus corderoi (FZB.Pyc–001). A. Dorsal view; B. Lateral view; C. Distal articles of 3^rd leg; D. Tibia 2, tarsus and propodus.

Colossendeidae Jarzynsky, 1870

Colossendeis Jarzynsky, 1870

(FZB.Pyc–002) 1 female, South Atlantic, July 8, 1964; (FZB.Pyc–004) 5 females, off Mar del Plata, Argentina (38°22'S, 55°37'W), May 1961, col. L.R. Pontes; (FZB.Pyc–005) 1 female, Uruguay, Mar1961.

Figure 3. 

Colossendeis megalonyx (FZB.Pyc–002), female. A. Dorsal view; B. Distal articles of palp; C. Distal articles of oviger; D. Tarsus and propodus.

Circumpolar. Antarctic, Western South America and up to Buenos Aires (Argentina), South Africa, Madagascar, New Zealand, Eastern South America (Child 1995a; Munilla and Soler-Membrives 2009; Scarabino et al. 2019). This is the first record for Uruguayan waters.

7 to 4900 m in depth.

Colossendeis megalonyx is a very variable species (Fry and Hedgpeth 1969; Child 1998b) and may represent a group of cryptic species. Only the long proboscis, palp article 8 shorter than articles 9 and 10 and a tarsus longer than the propodus remain stable amongst all examined specimens (Child 1995a). Variable characters are the shape and size of the ocular tubercle (elevated or short, conical or rounded), the occurrence of eyes (similar in size or larger anteriorly, well pigmented, white or even absent), the size of the proboscis (equal to, or longer than the trunk) and the size of the legs (either the femur or the tibia represent the longest article) (Child 1995a, 1998b; Cano-Sanchez and López-González 2007).

Molecular studies confirm that a complex of species exists under the name C. megalonyx. Five species and another seven cryptic species were indicated (Krabbe et al. 2010; Dietz et al. 2015; Dömel et al. 2020). These papers suggest the use of the name C. megalonyx for specimens from South America and the Subantarctic Region, the type locality (Krabbe et al. 2010; Dietz et al. 2015, 2019). Although morphology was not used for the delimitation of these species, subspecies were previously proposed by Fry and Hedgpeth (1969). This indicates that morphology can be used successfully for the delimitation of species (Cano-Sanchez and López-González 2007).

Specimens analysed thus should belong to C. megalonyx, as they were collected in Uruguay (the northernmost record for the species, a full two degrees of latitude north of the record provided by Child (1995a)). Further, they conform to the description of Hoek (1881). Yet, variations in the shape of the ocular tubercle were observed, in some specimens this structure being conical and in others, rounded. All specimens had a proboscis 1.5 times as long as the trunk, on average, the same proportion observed by Stock (1963) for individuals identified as C. orcadensis. Although molecular analyses are an important new source of evidence, their results need to be correlated with detailed morphological analyses, in order to corroborate or refute the recent results with the older morphological work available in literature.

Pallenopsidae Fry, 1978

Pallenopsis Wilson, 1881

(FZB.Pyc–003) 2 females, Garopaba, Santa Catarina, Brazil, 24 June 1975.

Scotia Sea, King George Island, Brazil: Santa Catarina, Rio de Janeiro and Espírito Santo. Brazil to USA (Georgia); Panama (Pacific) (Lucena and Christoffersen 2018a).

Figure 4. 

Pallenopsis candidoi (FZB.Pyc–003), female. A. dorsal view; B. lateral view; C. oviger; D. propodus.

Up to 430 m.

P. candidoi and P. fluminensis (Krøyer, 1844) are sympatric species, very frequent in depths between 10 and 100 m. These are the commonest species of Pallenopsis along the Brazilian coast. The two species are very similar, varying mainly in the number of setae on the legs (larger and more numerous in P. candidoi) and in the number of articles in the female oviger, in which article 6 is smaller than article 5 and 8 and is less than half as long as article 7 in P. candidoi (article 6 is the same size as article 5 and article 8 is almost the same size as article 7 in P. fluminensis) (Marcus 1940; Mello-Leitão 1949; Stock 1974; Lucena et al. 2017).

(FZB.Pyc–008) 1 female, St. 4512, 37°38'S, 56°56'W, Argentina, 25 Aug 1977.

Antarctic (Ross Sea, Weddell Sea) to southern Argentina (up to approximately 37°15'S), southeast Pacific (Strait of Magellan up to 33°S) (Weis et al. 2014; Scarabino et al. 2019).

Figure 5. 

Pallenopsis patagônica (FZB.Pyc–008), female. A. Dorsal view; B. Lateral view; C. Oviger; D. Propodus.

15–720 m (Child 1995b).

Literature records large morphological variations for this species (Hoek 1881; Hodgson 1907; Loman 1923; Gordon 1944; Child 1995b; Weis et al. 2014). These variations encompass mainly the proportion of the articles of the legs, the shape of the trunk, the structure of the propodus, the size and inclination of the abdomen and the size of the cement gland (Stock 1957; Pushkin 1993; Child 1995b; Cano-Sanchez and López-González 2019; Scarabino et al. 2019).

Recent studies, based mainly on molecular data, have indicated the existence of cryptic species under the name P. patagonica, mainly from the Antarctic Region (Weis et al. 2014; Harder et al. 2015; Dömel et al. 2017, 2019). These species form the P. patagonica sensu lato complex. Although no consensus exists concerning the number of possible new species (up to 19 clades have been proposed) and no morphological characterisation has been provided for the identified clades, specimens collected in the Falkland Islands and the Patagonian Region appear to belong to P. patagonica sensu stricto (Weis et al. 2014; Harder et al. 2015; Dömel et al. 2017, 2019), the type locality of the species.

The specimen analysed herein comes from northern Argentina, close to the northern range of the species (Child 1995b). This female individual has all the characters described by Hoek (1881), such as the indicated number of articles and the proportion established amongst the last articles of the ovigers, the same proportion amongst the articles of the legs and a similar body structure, with lateral processes separated by about less than half their own diameter and a cylindrical proboscis. In relation to subsequent descriptions, the present specimen is similar to P. meridionalis (today a synonym of P. patagonica), particularly in the shape of the ocular tubercle, structure of the propodus and ornamentation of the lateral processes (Pushkin 1993). However, the closest proximity is with P. yepayekae Weis et al. 2014, from which it may be distinguished by the number of articles on the oviger and in the number of setae on the abdomen (2 in the description, 4 in the individual at hand), including a cylindrical proboscis. However, we observed an undescribed character for P. patagoica, but reported for P. yepayekae and indicated as distinguishing the two species: the presence of brush-like setae in the ventral region of coxae 2 and 3. Hoek (1881) described the presence of setae in coxae 2 and 3, but did not illustrate them. In the cited material, such setae appear to be smaller and in lower number in the material analysed herein than in P. yepayekae.

Great morphological variation has been reported for several species from polar, temperate and tropical regions, where the genus is quite diverse (Stock 1974). Our data are insufficient for advancing previous taxonomic conclusions. It becomes necessary to conduct more in-depth morphological analysis and to extend the investigation to include samples from wider geographical locations. Species-group and genus-level revisions are necessary to distinguish diagnostic species characters from intrapopulational variations (Hennig 1950, 1968).