Online Dictionary of Invertebrate Zoology: Complete Work - Best Text

728Maggenti and Gardnerprimary intergradation An intermediate zone between twophenotypically different populations, developed in situ as aresult of selection. see secondary intergradation.primary iris cells see corneal pigment cellsprimary ligament (MOLL: Bivalvia) Original ligamental structureconsisting of periostracum, lamellar layer and fibrouslayers; not secondary additions such as the fusion layer.primary ocelli see dorsal ocelliprimary/periodical pleometrosis (ARTHRO: Insecta) In socialHymenoptera, a colony founded by a group of queens,however, after emergence of the first workers, all but onefemale disperse. see secondary pleometrosis, temporarypleometrosis.primary pigment cells see corneal pigment cellsprimary reproductive (ARTHRO: Insecta) In Isoptera, thequeen or male termite derived from winged adults, thatestablish a colony. see adultoid reproductive, nymphoidreproductive, ergatoid reproductive.primary riblet (MOLL: Bivalvia) In shells with various strengthof riblets, the riblet appearing early in development andremaining stronger than later ones.primary royal pair see primary reproductiveprimary segmentation The segmental division of the bodyoriginating in embryonic metamerism.primary setae (ARTHRO: Insecta) In Lepidoptera, setae with adefinite arrangement found on caterpillars in all instars.primary sexual characters Gonads and associated ducts.primary shell layer (BRACHIO) Outer layer under the periostracum;deposited by columnar epithelium of the outermantle lobe.primary somatic hermaphrodite see intersexprimary spicule (PORIF) A major structural megasclere.primary teeth (BRACHIO) The cardinalia or central teeth belowthe umbones.primary zooid (BRYO: Gymnolaemata) In some Cheilostomata,the ancestrula or one to several zooids simultaneously