Anocellidae, Quiroga, Bolaños & Litvaitis, 2006

Quiroga, Sigmer Y., Bolaños, D. Marcela & Litvaitis, Marian K., 2006, First description of deep­sea polyclad flatworms from the North Pacific: Anocellidus n. gen. profundus n. sp. (Anocellidae, n. fam.) and Oligocladus voightae n. sp. (Euryleptidae), Zootaxa 1317, pp. 1-19 : 3-5

Family: Anocellidae n. fam.

Definition: Ilyplanoidea without eyes. Ruffled pharynx located anteriorly; long, pointed tentacles present. Gonopores separate and male copulatory apparatus positioned posterior to male pore, hence directed forwards; armed with a long and pointed stylet directed backwards. Prostatic­like glands (prostatoid organs, sensu Faubel 1983) absent. Spermiducal bulbs present instead of a true seminal vesicle. Female apparatus with Lang’s vesicle. A ventral disk of potentially sensory function, positioned anterior to the cerebral ganglion; this organ is not homologous with the cotylean sucker.

Taxonomic remarks regarding the new family: According to Faubel (1983), the absence of a true prostatic vesicle is the taxonomic character defining the superfamily Ilyplanoidea which includes the families Enantiidae Graff 1889 , Discocelidae Laidlaw 1903 , Discoprosthididae , Euplanidae , Ilyplanidae , Mucroplanidae and Paluidae (the last five all by Faubel 1983). The ruffled pharynx and a male tract without a trace of prostaticlike glands or a prostatic vesicle would place this new species into the genus Aprostatum , within the Euplanidae . This family is defined by a ruffled, centrally located pharynx, a posteriorly­dircted male copulatory apparatus, separate gonopores, and a complete lack of prostatic­like glands ( Faubel 1983). Although these characters conform to those found in our new species, an additional character found in our specimens warrants the establishment of the new family Anocellidae .

The defining character of the Anocellidae is that the male copulatory apparatus is located posterior to the male gonopore and is directed anteriorly. This is exactly opposite of the condition found in the Euplanidae , where the male copulatory complex is located anterior to the male gonopore and directed posteriorly ( Table 1 ). Using a single character as a basis for a new family without a complete reanalysis of acotylean classification may appear precipitous, however, “orientation of male copulatory apparatus” weighs heavily in the classification system of acotyleans and has previously been used in defining families ( Faubel 1983). In fact, Lang (1884) used it as the main character to establish the Cestoplanidae , a group in which the male copulatory apparatus is located posterior to the male gonopore and is directed anteriorly. Other morphological differences however eliminate placement of the new species in the Cestoplanidae ( Table 1 ), thus justifying the establishment of the family Anocellidae .

Key for the determination of the new family (modified from Faubel 1983)

1. ruffled pharynx ............................................................................................................. 2

­ tubular or cylindrical pharynx, directed forwards........................................... Enantidae

2. male tract provided with prostatic­like glands .............................................................. 3

­ male tract completely lacking prostatic­like glands ...................................................... 7

3. male tract with glandular epithelium, prostatoid organs lacking .................................. 6

­ male tract with or without glandular epithelium, prostatoid organs present ................. 4

4. male tract without prostatic­like lining ......................................................................... 5

­ male tract with prostatic­like lining ................................................... Discoprosthididae

5. male tract edged with numerous prostatoid organs .................................... Discocelidae

­ male tract without prostatoid organs; a single armed prostatoid organ opens independently from the male tract to the exterior......................................................... Palauidae

6. like (3) and with bulbous, glandular chambered penis, prostatic­like glands are extraepithelial .......................................................................................... Mucroplanidae

­ penis if present, is papilla­like rod­like or armed with a cuticular stylet...... Ilyplanidae

7. male copulatory apparatus positioned anterior to male pore, hence directed backwards ....................................................................................................................... Euplanidae

­ male copulatory apparatus positioned posterior to the male gonopore, hence directed forwards; eyes lacking.................................................................................. Anocellidae

Tables

TABLE 1. Comparison of morphological features of the new family Anocellidae with Euplanidae and Cestoplanidae.

Character	Anocellidae	Euplanidae	Cestoplanidae
Body form	Round to oval	Elongate, oval or cuneate	Very elongate, slender
Tentacles	Nuchaltentacles present	Absent or rudimentary	Absent
Eyes	Absent	Well­developedmarginal eyes; tentacular, frontal and cerebral eyes­spots present	Eye­spots scattered over anterior end; definite cerebral and tentacular eyes absent
Prostatic vesicle	Absent	Absent	Present, interpolated
Location of male copulatory complex	Posterior to male gonopore	Anterior to male gonopore	Posterior to male gonopore
Orientation of male copulatory complex	Directed anteriorly	Directed posteriorly	Directed anteriorly
Ventral, sensory disk	Present	Absent	Absent