Balanidae

Hosie, Andrew & Ahyong, Shane T., 2008, First records of the giant barnacles, Austromegabalanus nigrescens (Lamarck, 1818) and A. psittacus (Molina, 1782) (Cirripedia: Balanidae) from New Zealand, with a key to New Zealand Balanidae, Zootaxa 1674, pp. 59-64 : 62-63

Key to the Balanidae known from New Zealand

For definitions and illustrations of terms see Foster (1978) and Pitombo (2004).

1. Radii broad, inner face with longitudinal abutment near sheath margin, permeated with tubes................. 2

- Radii narrow, without longitudinal abutment or tubes ................................................................................ 6

2. Spur furrow open ......................................................................................................................................... 3

- Spur furrow closed, or nearly so.................................................................................................................. 4

3. Parietes smooth. Radii pink ................................................................................ Notomegabalanus decorus

- Parietes ribbed. Radii white............................................................................ Notomegabalanus campbelli

4. Tergum with projecting spine-like apex. Shell smooth ............................................................................... 5

- Tergum with angular apex, not spine-like. Shell ribbed; dark reddish-purple............... Megabalanus linzei

5. Adductor ridge of scutum confluent with articular ridge. Shell white-pink ... Austromegabalanus psittacus

- Adductor ridge of scutum separate from articular ridge. Shell whitish-blue to purple, often darker when eroded .......................................................................................................... Austromegabalanus nigrescens

6. Scutum with one or more rows of longitudinal pits. Shell pink to purplish red with white ribs................... ..................................................................................................................... Balanus trigonus Darwin, 1854

- Scutum not as above .................................................................................................................................... 7

7. Basal margin of tergum excavated on both sides of spur. Spur longer than wide. Shell cross-hatched with purple stripes. Labrum simple. ................................................... Amphibalanus variegatus ( Darwin, 1854)

- Basal margin of tergum not excavated on either side of spur. Spur as long as or shorter than wide. Shell white with solid grey to purple longitudinal stripes. Labrum multidenticulate............................................. ..................................................................................................... Amphibalanus amphitrite ( Darwin, 1854)