Ozestheria Schwentner and Richter

Schwentner, Martin, Rabet, Nicolas, Richter, Stefan, Giribet, Gonzalo, Padhye, Sameer, Cart, Jean- François, Bonillo, Céline & Rogers, D. Christopher, 2020, Pseudosesarma crassimanum, Zoological Studies (Zool. Stud.) 59 (44), pp. 1-23 : 14-15

Ozestheria Schwentner and Richter , in Schwentner, Just, and Richter, 2015

Diagnosis: (modified from Schwentner et al. 2015). Populations composed of males and females; amplexus is venter to venter. Male and female rostrum triangular. Ocular tubercle smoothly arcuate. Angle between rostrum and frons 150° to 170°. Occipital condyle either short and rounded or elongated and subacute. Carapace valve length ~1.5 times valve breadth (hinge to margin). Carapace with or without sculpturing between growth lines (scarring from algae often mistaken for sculpture). Carapace typically dark brown. Male thoracopod I and II with endopod (= movable finger) bearing one or more transverse apical rows of flattened, broadly subtriangular denticles (claw-like scales) ( Fig. 1H ). Endite IV broadly transverse to cylindrical, bearing a dense, apical field of short spiniform setae. Eggs attaching to prolonged exopods of thoracopods IX and X. Thoracopod exopods lacking a triangular lamina. Posterior trunk segments with several medial dorsoposterior spines per segment. Telson posterior margin posteriolateral spine rows confluent dorsally, with confluence not projecting. Each row with 10 to 30 spines. Caudal filament originating between spine rows at fifth, sixth, or seventh spines from confluence. Caudal filament borne on projecting mound or not. Cercopods sinuate to curved. Cercopod with medial longitudinal setal row on proximal 40– 60%. Setae plumose and either long or short. Setal row terminates with single spine. Cercopod with subapical, dorsal cirrus, extending from 60–40% of cercopod length.

Comments: Ozestheria lutraria ( Brady, 1886) is the type species (Schwentner et al. 2015). This genus is morphologically defined by the clasper endopod bearing one or more transverse apical rows of flattened, broadly subtriangular denticulae (“claw-like scales”). Several forms previously treated at Cyzicus are here reported as Ozestheria , with the result that Ozestheria is no longer considered to be endemic to Australia. The distribution of this genus apparently extends to Africa and Asia as well suggesting to be primarily Gondwanan, with an extension into Asia. It is currently unclear if further species, which are currently identified as Cyzicus , in fact belong to Ozestheria . But at this time we can confidently ascribe at least one Asian species to this genus: Ozestheria pilosa (Rogers, Thaimuangphol, Saengphan, & Sanoamuang, 2013) new combination.

Eocyzicidae, Schwentner, Rabet & Rogers, 2020 , fam. nov.

= Caenestheriidae Daday, 1913: 12 (pro partim)

Diagnosis: (Modified from Rogers et al. 2017). Populations composed of males and females; amplexus is venter to venter. Rostrum typically sexually dimorphic. Rostrum subtriangular (usually females) to subquadrate (usually males) or rounded. Adult rostrum not armed with an apical spine (sometimes present in juveniles). Angle between rostrum and frons 170° to 190°. Occipital notch very shallow or absent. Occipital condyle low, rounded or absent, length half or less basal width. Carapace valve length ~1.5 times valve breadth (hinge to margin). Carapace growth line intervals smooth or weakly ornamented (scarring from algae often mistaken for ornamentation). Carapace typically whitish and partly translucent. Clasper endopod apically with one or a few elongated scales, each scale laterally fringed. Endite IV broadly transverse to cylindrical, bearing a dense, apical field of short spiniform setae. Thoracic segments smooth or with a central dorsoposterior projection and/or set of spines or setae. Eggs attaching to prolonged exopods of thoracopods IX and X. Thoracopod epipods lacking a triangular lamella. Telson posterior margin posteriolateral spine rows confluent dorsally, with confluence not or slightly projecting. Each row has from six to 30 spines depending on species and gender. Females typically have more and smaller spines than males. Caudal filament originating between spine rows at fifth, sixth, or seventh spines from confluence. Caudal filament borne on projecting mound. Cercopods arcuate or straight. Cercopod with a dorsomedial longitudinal row of setae or spines on proximal 40–60%. Setae plumose and either long or short. Row terminates with single spine. Cercopod with subapical, dorsal cirrus, extending from 50–40% of cercopod length. Eggs smooth or with surface polygons.

Comments: The type genus is fixed here as Eocyzicus . Naganawa (2001) treated Eocyzicus as a junior synonym of Cyzicus , however. this is not supported by this and previous molecular studies (Schwenter et al. 2009 2018; Weeks et al. 2009).

Figures

Fig. 1. Figure 1. Representative Spinicaudata and their typical head shapes. A) Ozestheria altus Shu et al., 2015, male head left lateral view; B) Cyzicus californicus (Packard, 1874), female head left lateral view; C) Ozestheria pilosa (Rogers et al., 2013), male head left lateral view; D) Leptestheria kunmingensis Shu et al., 2015, male head left lateral view; E) L. kunmingensis Shu, et al., 2015, female head left lateral view; F) Eocyzicus taiwanensis Rogers et al., 2017, male head left lateral view; G) Ozestheria sp. “Mongolia”, DCR collection 729, male head left lateral view; H) Ozestheria sp. “Mongolia”, DCR collection 729, male limb I endopod distal portion, right lateral view; I) Metalimnadia sp. DCR collection 853, male head left lateral view; J) Eoleptestheria cf. ticinensis from Australia, male head left lateral view. Designations: f = fornix; on = occipital notch; oc = occipital condyle; rs = rostral spine; r = rostrum.