Carinaria lamarcki Péron and Lesueur 1810

Introduction

This is the second largest species (to 220 mm body length) among the six species of Carinaria. The proboscis and trunk are large, due to the presence of a thick cutis layer. The shell is broadly triangular in side view and shares with C. challengeri the lowest shell height to basal length ratio (0.5). The keel is moderately low, and increases in height gradually with increasing proximity to the shell aperture. The tail is moderately small, with a low dorsal crest.

Brief Diagnosis

A species of Carinaria with:

• Proboscis and trunk large, due to thick cutis
• Shell broadly triangular in side view
• Keel moderately low, increasing in height gradually with shell growth
  
• Tail moderately small; dorsal crest low
  

Characteristics

1. Body morphology (see title illustration)
   1. Proboscis short and trunk long; cutis thick
      
   2. Eye shape triangular in dorsal view
   3. Left tentacle long; right one greatly reduced
      
   4. Tail moderately small, with low dorsal crest
      
      
2. Shell morphology
   1. Shell laterally compressed and broadly triangular in side view;
      
   2. Shell height about one-half the basal length; ratio = 0.8-1.0
   3. Keel moderately well developed, with height increasing gradually with increasing proximity to shell aperture
      

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      Figure. Stalked visceral nucleus with transparent shell in Carinaria lamarcki, viewed from right side of body. ©

   4. Shell apex in adult shells with ventrally-directed protoconch
      

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      Figure. Apical portion of shell in Carinaria lamarcki, from right side (left) and close up of protoconch (right). ©

3. Radula with a central, rachidian tooth bearing three elongate and pointed median cusps, the middle one of which is slightly longer than the other two
   
   

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   Figure. Scanning electron micrographs of the radula of Carinaria lamarcki at low (left) and high (right) magnifications. Scale bars = 200 µm (left) and 20 µm (right). Photographs modified from Richter and Seapy (1999). © G. Richter

4. Larval morphology (after Thiriot-Quiévreux, 1975)
   1. Brown pigment on the mantle, digestive tube and opercular lobe; digestive gland yellow
      
   2. Velum comprised of six velar arms; each arm is bordered by a thin line of brown pigment and with a terminal small brown patch
      
   3. Larval shell transparent and globular, with oval aperture; low, conical spire; and, two elevated spiral ridges on second whorl, the outer most of which does not extend as far around the shell whorl as the inner one
      
      

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      Figure. Scanning electron micrographs of Carinaria lamarcki larval shells, viewed from the aperture (left), right side, tilted (center), and right side, spire (right). Photographs modified from Thiriot-Quiévreux (1975; Fig. 1E-G). © 1975 C. Thiriot

References

Richter, G. and R. R. Seapy. 1999. Heteropoda, pp. 621-647. In: D. Boltovskoy (ed.), South Atlantic Zooplankton. Leiden: Backhuys Publishers.

Seapy, R. R. and C. Thiriot-Quievreux. 1994. Veliger larvae of Carinariidae (Mollusca: Heteropoda) from Hawaiian waters. Veliger 37:336-343.

Thiriot-Quiévreux, C. 1975. Observations sur les larves et les adulte de Carinariidae (Mollusca: Heteropod) de l'Océan Atlantique Nord. Marine Biology 32: 379-388.