paragnath

See: labium, metastoma [Martin, 2005].

A pair of ventral projections of the cephalic cuticle just posterior and medial to the mandibles. Each projection has two lobes, a broad lamellar outer lobe with hair-like setae on the inner margins and a thick inner lobe covered with many hair-like setae. (Syn. paragnathae or lower lips) [Wilson, 1989].

See: metastoma [McLaughlin, 1980].

(Order Cladocera):

Labium [Stachowitsch, 1992].

(Order Notostraca):

One of a pair of lobe-like structures between mandibles and maxillules posterior to mouth. Considered to represent either true lower lip or additional lobe of each maxillule [Stachowitsch, 1992].

(Order Anostraca):

On underside of head, structure posterior to mouth between mandibles and maxillules; considered to represent or at least function as lower lip [Stachowitsch, 1992].

(Order Decapoda):

Labium [Stachowitsch, 1992].

(Order Amphipoda):

Labium [Stachowitsch, 1992].

(Order Isopoda):

In isopods, the labium is usually produced and cleft into a large bilobed structure, and hence more commonly referred to as the paragnath (=hypostome, mesastome, hypopharynx) [Wetzer et al. 1997].

(Order Isopoda):

One two lobes of labium [Stachowitsch, 1992].

(Order Mysida):

Labium [Stachowitsch, 1992].

(Order Stomatopoda):

Labium [Stachowitsch, 1992].

(Order Leptostraca):

One of two lobe-like structures forming lower lip (labium) posterior to mouth [Stachowitsch, 1992].

(Subclass Branchiura):

One of two lobes of lower lip (labium); either papilla-shaped elevations posterior to mouth or reduced, along with labrum, to serrate flap enclosed in proboscis [Stachowitsch, 1992].

(Subclass Copepoda):

A pair of articulating lobes often bearing setae and located posterior to the mandible and anterior to maxilla 1. Homologies of the paragnath have not been determined, but it may be the praecoxa of the mandible or it may be that section of the praecoxa of maxilla 1 bearing a second lobe [Ferrari and Dahms, in press].

(Subclass Copepoda):

A small paired lobe located on ventral surface of cephalosome, between the bases of mandibles and maxillules [Boxshall and Halsey, 2004].

(Class Ostracoda):

Labium [Stachowitsch, 1992].

(Class Ostracoda):

One of two lobes of lower lip (labium) [Stachowitsch, 1992].

(Class Remipedia):

One of a pair of lobes flanking opening (atrium oris) to mouth; margin of each paragnath bear dense cover of ribbon setae [Stachowitsch, 1992].

(Superorder Syncarida):

One of two lobe-like structures forming lower lip (labium) posterior to mouth [Stachowitsch, 1992].

(Order Thermosbaenacea):

Labium [Stachowitsch, 1992].

(Order Euphausiacea):

One of two lobe-like structures forming lower lip (labium) posterior to mouth [Stachowitsch, 1992].